Final Report Summary - PRE-XFEL (Preparatory activities for the implementation of the European X-ray free-electron laser facility)
Executive summary:
The objectives of the preparatory phase of the European x-ray free-electron laser facility, a research infrastructure of the European Strategy Forum for Research infrastructures (ESFRI) roadmap, were the promotion and the acceleration of all processes necessary to transform this strategic scientific proposal into a working research institute, organised to build and operate one of the most innovative scientific instruments worldwide: a source of ultra-short and very bright flashes of coherent x-rays, able to disclose not only the atomic configuration of materials and molecules, but also the atomic dynamics, i.e. its evolution in time during chemical reactions and phase transformations.
At the end of the PRE-XFEL period that lasted from 15 June 2007 to 15.06.2011 there is:
1. an intergovernmental convention (30 November 2009) establishing the European x-ray free-electron laser facility, signed by representatives of 11 governments and including annexes detailing technical and administrative specifications;
2. a limited liability company under German law, the European x-ray free-electron laser facility GmbH (European XFEL), created on 28 September 2009, with research institutions of the participating countries as shareholders, with over 80 employees actively engaged in the construction of the facility and a fully operational management structure and overseeing committees, according to the best governance standards of international research institutions in Europe;
3. a vast international effort to contribute to the construction of the facility. On the one hand, many laboratories from the participating countries are contributing in-kind vital components of the linear accelerator, of the undulator systems (the devices producing the ultra-short bursts of coherent x-rays) and of the photon beamlines and instrumentation systems; on the other, the potential scientific use of the facility after 2015 has been discussed with the community in a series of general users' meetings and thematic workshops, taking place in eight different countries, as well as in schools for young scientists and information days, involving thousands of scientists in the process.
The project is therefore well on its way to its implementation and to the realisation of its ambitious scientific goals.
Project context and objectives:
The history of European collaboration in science and in particular in the establishment of large research infrastructures, can boast remarkable successes such as Organisation Européenne pour la Recherche Nucléaire (CERN), Institut Laue-Langevin (ILL), European Synchrotron Radiation Facility (ESRF), European Organisation for Astronomical Research in the Southern Hemisphere (ESO), to name just a few among many. Nonetheless, the actual process leading from a brilliant scientific concept to a functioning international institution is long and difficult. Some of the main steps and hurdles are:
1. to organise an international scientific consensus on the necessity of the project;
2. to identify and obtain agreement on a site for the proposed facility;
3. to convince a government or an initial core group of governments to spearhead the initiative and to pursue the effort to create the new facility;
4. to secure initial funding for the establishment and support of committees and of a core technical and scientific group in charge of the full design and costing proposal;
5. to facilitate the convergence of financial agreements and cost repartition among the potentially interested countries to secure the financing of the new institute;
6. to reach agreement on the governance, legal and administrative texts lying at the heart of the founding document (convention).
The initial concept of the European x-ray free-electron laser facility was developed in the last decade of the past century, by an international collaboration centred at the Deutsches Elektronen-Synchrotron (DESY) laboratory in Hamburg. The scientific case merges two highly successful achievements of modern physics in providing instruments that benefit all natural sciences: synchrotron light sources on the one hand and ultra-fast (femtosecond) lasers on the other. Synchrotron rings have proven themselves as extremely brilliant sources of x-rays, an electromagnetic radiation with a wavelength comparable to the size of atoms, or to the distance between atoms in matter under normal conditions. This makes them the ideal probe to investigate (one could say 'to see') the atomic structure of matter, i.e. the detailed arrangement in space of the atoms constituting a solid material or a biological molecule. Lasers, in their 50 years of history, have made tremendous progress and are today available for a variety of applications in science and industry. Great strides have in particular been made in the production of intense and extremely short pulses: femtosecond (fs) lasers are available commercially and many laboratories are developing and using attosecond (as) pulsed lasers for scientific purposes. These ultra-short pulses are very useful to investigate the dynamics of chemical reactions or of relaxation and phase transformation processes. Since the typical time scale of atomic motion in such processes is a picosecond (ps), flashes of fs duration can provide snapshots in which atoms are caught in their instantaneous positions. Lasers however produce wavelengths in the visible, infrared or ultraviolet, which are many thousands of times longer than atomic distances and therefore unsuitable to explore the atomic structure of matter - although they have proven of revolutionary importance in other areas of science. A free-electron laser (FEL), based on a high-energy electron accelerator, can produce radiation in pulses as short as a few fs and, at the same time, with a wavelength comparable to the atomic distances.
Worldwide scientific interest in such tools is enormous. X-ray FEL projects are vigorously pursued in the US, in Japan, in South Korea and of course in Europe. The European x-ray free-electron laser facility has a formidable advantage in comparison with all other competitors: its linear accelerator exploits the superconducting accelerator technology, which allows production of many thousands of pulses per second (27 000 is the design value); competing facilities have typically 120 pulses per second, or less.
In 2003 the German government announced its intention to go ahead with the realisation of the project as an international one, in which at least 40 % of the financial resources had to come from foreign sources. Following intense consultations, a memorandum of understanding was signed, in 2004 and 2005, by representatives of China, Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. As an implementation of the memorandum, the European XFEL project team was appointed and installed at DESY in Hamburg, in late 2005, to prepare the foundation of an independent research organisation that will build and operate the European XFEL, i.e. the European XFEL GmbH. The application for the building permit, submitted to the competent German authority in April 2005, was approved in July 2006; a few days later, the European XFEL project team handed over the technical design report (TDR) for the European XFEL to the chairman of the international steering committee, the main decision body foreseen in the memorandum of understanding. The 600 pages thick TDR has over 300 authors, from 71 institutes in 17 countries.
The project took a further step forward when 260 scientists from 22 countries came to Hamburg to participate in the first European XFEL users' meeting, on 24 and 25 January 2007. The main topics of discussion were the requirements of the future users as input for the detailed planning of the experimental stations, the development of novel detectors and experimental techniques.
On 5 June 2007, the German federal minister of education and research, Dr Annette Schavan, in presence of the Russian and French ministers of research, of the presidents of the regional governments of Hamburg and Schleswig Holstein and of other high officials, launches the European XFEL. Germany and the participating countries agree to begin the construction of a 'start version', a facility with slightly less design margins in the linear accelerator, 3 (instead of 5) undulators and photon beamlines and 6 (instead of 10) experimental stations.
At this point, it seemed to many that the signature of the intergovernmental convention, the official creation of the European XFEL company and the first steps of the newly born European research infrastructure would be only a few months away.
In this context, in June 2007 the Pre-XFEL contract started. Its objectives were:
1. the completion of the legal texts (convention, articles of association, bylaws for the new research institute, etc.)
2. the drafting of procedures and rules for the in-kind contributions to the facility to be built
3. the acceleration of the build-up of the staff, in particular scientists and engineers, in order to allow immediate start of design and construction work, even before completion of the formal founding steps
4. a strong programme of outreach to the natural sciences communities in Europe, to involve them in the formulation of a robust scientific program and in the indispensable research and development (R&D) work for the development of suitable instrumentation.
The idea was to use the contract resources in the most efficient way as a catalyst for the rapid take-off of all aspects of the project. Thanks to the support from the contract, a large number of committee meetings and actions for the achievement of objectives one and two were possible; objective three was pursued by using the PRE-XFEL contract resources to support employment of personnel by beneficiary laboratories and by subsequent detachment to the project team in Hamburg. This made the achievement of a team of extremely motivated, enthusiastic young scientists and engineers possible at an early stage and supported also the build-up of the necessary infrastructure to start work. Legal and administrative staff to support objectives one and two was also put in place at an early stage. Objective four was pursued with the organisation of specialised meetings and workshops devoted to specific experimental techniques or components of instrumentation and of general information meetings. Thousands of scientists throughout Europe were involved in these activities.
Project results
The European x-ray free-electron laser facility GmbH was created in 29 September 2009 by DESY as the only shareholder; on 30 November 2009 the signature of the intergovernmental 'Convention concerning the construction and operation of a European x-ray free-electron laser facility' in Hamburg, provided the basis for shareholders of the other participating countries to join. The participating countries that signed the Convention so far are, in alphabetic order: Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovakia, Sweden and Switzerland. Spain was expected to sign in autumn of 2011.
At the end of the PRE-XFEL contract, the project is in full swing into the construction phase. A new international European research infrastructure has come to life, its technical implementation is well under way and a well-developed governance system is in place. This is the main result of the PRE-XFEL contract and it shall be illustrated in detail in the following. For clarity and convenience, it is useful to separate the milestones achieved in the scientific/technical implementation of the project, on the one hand, from the legal, organisational and governance structures that have been defined and set up, on the other.
Scientific and technical results
Civil construction activities
Starting on the DESY campus, a nearly 2 km long linear accelerator imparts a 17.5 GeV energy to electrons; the highly accelerated electrons are then sent through undulators, systems of magnets which force the electrons to a zig-zag trajectory and generate intense bursts of coherent x-rays. The electrons are then stopped against large copper and graphite cylinders, while the x-ray bursts are channelled through long (up to about 1 km) photon beamlines to the experimental hall, 3.4 km away from the electron starting point on the DESY campus. All of the buildings so far described are underground, at a depth varying between 6 and 28 m below the surface. Only an office and laboratory building above the experimental hall and the access buildings above the other shafts are above the ground. Accelerator components, undulators and photon beamlines are in tunnels with a diameter of about 5.5 m; the total length of tunnels is 5.7 km.
Civil construction activities started in January 2009, in three separate building sites, corresponding to major shafts: one on the DESY Bahrenfeld campus, the second in Osdorfer Born and the third in Schenefeld, where the Experimental Hall is located. Actual work in the field started on 8 January 2009, with some preparatory work starting even earlier, in December 2008. Preparatory work included modification or construction of access roads, removal of trees and other vegetation where needed, installation of construction site offices, displaying construction site panels, fencing, installing water and power access, performing search for explosives and setting up concrete (Schenefeld and Bahrenfeld) and bentonite facilities.
At the DESY-Bahrenfeld site, 110 000 m3 soil of the Lise-Meitner-Park were removed and the excavation of the 34 m deep and 1 500 m2 sized watertight building pit for the injector complex was started, with 80 000 m3 removal of soil. The excavation there was completed in late 2010 and the construction of the injector building, with seven stories from the bottom of the shaft up to the ground level, started. In June 2011, the concrete structure of the building was completed and the roof is now visible above ground level.
Similarly work started and progressed rapidly also in the Osdorfer Born site. In Schenefeld, excavation of the 90 X 50 m2 hall and of the smaller shafts corresponding to the branching points of the undulator tunnels (XS2, XS3, XS4) also progressed essentially according to schedule.
In July 2010 the first tunnelling machine started the digging of the tunnels connecting the shafts and was joined by a second one in December 2010.
In June 2011, at the end of the PRE-XFEL contract, 3 km of tunnels were already excavated and the completion of the main linear accelerator tunnel XTL was only a few weeks away. The progress of the tunnelling works can be followed in real time via a public web page (http://www.xfel.eu/project/construction_progress/(odnośnik otworzy się w nowym oknie)) accessible from the home page of the XFEL project (http://www.xfel.eu/)(odnośnik otworzy się w nowym oknie); details about the current and past activities of the two tunnel machines can be found there.
Thanks to the PRE-XFEL support, it was possible to create, staff and put to work an international project team ahead of the creation of the company and, making full use of German funds channelled via DESY, to start the civil engineering work after the June 2007 decision to go ahead with the project. In this way, the delay in achieving foundation texts agreed by all partners was not entirely reflected on a project delay.
Development and construction of the accelerator
In the general organisation for the construction of the European XFEL, the construction of the linear accelerator is entrusted to the 'accelerator construction' consortium, a group of 15 laboratories from the participating countries, coordinated by DESY and is going to be delivered to the European XFEL company as an in-kind contribution. This may look at first as a complex and risky strategy, were it not for the fact that most of the laboratories involved in the consortium have worked together for many years in the development of the superconducting 'TESLA' technology and in the construction of the accelerator for the FLASH vacuum ultraviolet (VUV) and soft x-ray FEL operating in Hamburg since 2004; FLASH, besides being a very successful user facility on its own, can also be regarded as a large scale validation prototype for the European XFEL. The laboratories involved in the consortium are:
1. DESY, Hamburg and Zeuthen, Germany (coordinator)
2. Atomic Energy Commission (CEA) Saclay, France
3. Centre national de la recherche scientifique, Laboratoire de l'Accélérateur Linéaire (CNRS-LAL) Orsay, France
4. Istituto Nazionale di Fisica Nucleare (INFN) Milano, Italy
5. Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid, Spain
6. Soltan Institute, Swierk, Poland
7. University of Wroclav, Poland
8. Institute of Nuclear Physics (IFJ-PAN), Cracow, Poland
9. Budker Institute, Novosibirsk, Russia
10. Institute for High Energy Physics (IHEP), Protvino, Russia
11. Institute for Nuclear Research (INR), Troitsk, Russia
12. Efremov Institute, Saint Petersburg, Russia
13. University of Stockholm, Sweden
14. University of Uppsala, Sweden
15. Paul Scherrer Institute, Villigen, Switzerland.
The cryomodule contains components built or procured by DESY, INFN Milano, LAL Orsay, CIEMAT Madrid, Soltan Institute in Swierk; the cryomodules are going to be assembled in a facility set up in Saclay by CEA and tested in Hamburg in the accelerator module test facility (AMTF), a large hall built by DESY, with cryogenic and radio frequency (RF) equipment built in a German-Polish-Russian collaboration; all cryomodules shall undergo such testing before being installed in the tunnel. The production of this large series of cryomodules and of their components (among which are over 800 high quality superconducting niobium radio-frequency cavities) is a major challenge for industry as well. A substantial amount of know-how was transferred to industry during the qualification and tendering exercises.
As it is the case for most of the components of the European XFEL accelerator, the cryomodules design is based very heavily on the FLASH corresponding components, with modifications inspired by the several years of careful monitoring of the performance during operation of that facility. The same holds for the injector, the system that imparts the first acceleration to the electrons emitted from the photocathode in the electron gun and impresses a high collimation and very tight transverse section on the electron bunches, to be preserved as much as possible along the whole acceleration chain, a crucial requirement for the lasing process that shall take place more than 2 km downstream, when the electrons radiate in the undulators. The injector for FLASH and presently the one for the European XFEL have been developed by DESY in its Zeuthen and Hamburg labs.
Development and construction of undulators
The accelerated electron bunches emerging from the long linear accelerator are sent through the undulators, where they are subjected to magnetic fields pointing in alternate directions, which force the electrons to follow a zig-zag trajectory and radiate; if the quality of the electron bunches and of the undulators is sufficient, the emitted radiation consists of bursts of coherent x-rays. Three undulators are foreseen for the 'start-up' version of the European XFEL and they range in length from about 100 to 180 m. Two, called SASE1 and SASE2 are specialized for the production of hard x-rays, whereas the third one, SASE3, is devoted to the production of soft x-rays. The quality of the electron bunches is given, as explained in the previous section, by their collimation and tight transverse section; the quality of the undulators by the accurate periodicity of the magnetic fields. undulators are composed, in the design chosen for the European XFEL, of 5 m segments, each of which contains a lower and an upper array of permanent magnets, separated by a gap of the order of a cm, that should be adjustable, in order to tune the wavelength of the emitted radiation. The perfect parallelism and the precise identical separation (down to µm level) of the upper and lower arrays in all the segments are needed for the required field quality. This level of mechanical precision is a formidable engineering problem, as the magnetic forces between the upper and lower magnet arrays are gigantic and the frames are therefore vey bulky mechanical supports. Here again the experience from FLASH is very useful, although the tolerances for longer wavelengths (VUV and soft x-rays) are more relaxed, the total length of the FLASH undulator is about 30 m and the gap between the magnet arrays is fixed and not tuneable.
At the end of the PRE-XFEL contract, that supported engineering recruitments for the Undulator group at an early stage, two generations of 5 m segment prototypes had been delivered, the second generation being tested in the undulator labs at the time of this writing. After evaluation of the prototypes, orders for the series production will be tendered out, with an increased confidence level on the quality of the resulting products.
In between undulator segments, 'intersections' are foreseen, where sensitive instruments are used to measure and to correct electron trajectories for optimisation of lasing properties. These are being developed and built with the help of Swedish and Spanish in-kind contributions.
Photon beamlines and diagnostics
After the x-ray pulses are produced in the undulators, they must be transported to the Experimental Hall, without degrading their quality, analyzed to determine their exact properties, which may be very important to evaluate the experimental results and, if needed, filtered or modified. For example, some experiments may need a very narrow interval of wavelengths, which is achieved by a monochromator; other experiments may need a focused beam and therefore require optical devices such as curved mirrors, or Fresnel zone plates. All of the necessary or desirable components must be especially designed and built, to be adapted to the unprecedented properties of x-ray laser-like beams. The transport and the conditioning of the pulses is the task of the optics group; the analysis of the properties of the pulses is the task of the photon diagnostics group. Both groups took great advantage of the PRE-XFEL grant to ensure the recruitment of the necessary scientific and engineering staff, starting already in 2007; the milestone foreseeing viable optical and diagnostics components installed in 2015 is very demanding; but it would have been absolutely untenable without this early start.
In April 2011, the optical layout for the photon beamlines was the object of a conceptual design review by the scientific advisory committee, which gave a positive opinion about the timeline, the assessment and the handling of technical risks. The diagnostics work package is also showing good progress and design of appropriate devices is under way at the European XFEL and via collaborations with DESY and with the Joint Institute for nuclear research in Dubna, Russia. In February 2010 a specialized workshop devoted to 'X-ray diagnostics and scientific application of the European XFEL', supported by PRE-XFEL grant, was held in Ryn, Poland. The over 60 attendants had an opportunity to contribute to the specifications of the diagnostics system.
Experimental stations
The three undulators foreseen in the initial phase of the European XFEL send photon pulses down the corresponding photon beamlines, which end in the experimental hall. Here six experimental stations (or 'instruments') are located, as every beamline can feed alternatively two instruments (for example, switching the beam between them every 12 hours, or with whatever timing is best suited to the users). Each instrument is devoted to a well-defined experimental technique, or to a special scientific domain. The definition and specification of the six instruments was the object of a vast consultation with the scientific community, as six of the altogether nine workshops organised with support of the PRE-XFEL grant were each devoted to one of the six instruments; actually the seventh one was also devoted to the two instruments served by the soft x-ray undulator. Since the attendance to each workshop was between 35 and 115 participants and each was held in a different country, to facilitate a good national balance in the participation, the claim of a wide consultation with the scientific community is well founded. A good age distribution was also aimed at, by granting PRE-XFEL travel support funds to young scientists.
At present, individual instruments are undergoing conceptual design reviews by the scientific advisory committee. The first two, namely small quantum systems (SQS) and femtosecond x-ray experiments (FXE) were reviewed in April 2011.
Detectors are important components of all experimental stations and deserve special mention here. One of the conditions for the success of the European XFEL is going to be the ability to use the uniquely high number of x-ray pulses per second generated by the FEL, based on a superconducting Linac. One crucial element of the strategy to implement this goal is the development of detectors with appropriate time-response characteristics, in particular capable of distinguishing x-ray pulses separated by as little as 220 nanoseconds. This requirement is especially challenging for area detectors, with typically millions of pixels.
This is why three separate ambitious projects for area detectors were solicited from international consortia of laboratories with world class reputation in detector development, as a result of an open call for expressions of interest. The three detectors under development, besides the mentioned response time requirements, have dynamic ranges, noise levels, spatial resolution, etc., properties that make each of them best suited for a particular class of experiments. In this sense, the success of all of them would not produce redundancy and would not correspond to an inefficient use of resources, quite the opposite being true. The proposals from the three consortia were selected with the help of an advisory committee of well-known experts, the so-called detector advisory committee (DAC), which has continued to assist the management board in monitoring the progress of the approved projects. The three projects and the respective consortia are:
1. Large pixel detector (LPD), STFC/Rutherford Appleton Laboratory and University of Glasgow (United Kingdom)
2. DEPMOS Sensor with Signal Compression (DSSC), MPI-Semiconductor Lab, Garching, Germany; University of Heidelberg, University Siegen (Germany); Politecnico di Milano, Università di Bergamo (Italy); DESY, Hamburg
3. Adaptive gain integrating pixel detector(AGIPD), DESY, Hamburg; PSI/SLS (Switzerland); University of Bonn (Germany); University of Hamburg (Germany).
In addition to the independent developments of each project, research on problems common to all detectors, i.e. the effects of intense irradiation on the detector sensors (radiation damage and possible anomalies of the electronic response due to the large amount of charges generated by each pulse) are handled in a common way under the coordination of the European XFEL, in collaboration with the University of Hamburg and other institutes. A computer program was also developed to simulate the expected signal from a given experiment and to compute the corresponding detector performance.
In the case of the LPD project, a complete prototype for testing and calibration could become available in early 2013.
Reaching out to the European scientific community: Workshops, meetings and schools.
One of the most important work packages of the PRE-XFEL contact was devoted to 'Coordination activity on the XFEL users' community'. Here the objective was to mobilise the scientific community to contribute to the shaping of the scientific program of the facility and to the corresponding instrumental developments. This was implemented by organising four general users' meetings in Hamburg and nine specialised workshops around Europe devoted to the six instruments or to other important aspects of instrumentation. In addition some support was also given to special events with strong educational character for young scientists. In the following a list of events with a few key data is given.
General users' meetings:
1. Users' meeting 2008, Hamburg, 23 and 24 January 2008, 252 participants
2. Users' meeting 2009, Hamburg, 28 and 29 January 2009, 256 participants
3. Users' meeting 2010, Hamburg, 27 to 29 January 2010, 281 participants
4. Users' meeting 2011, Hamburg, 26 to 28 January 2011, 319 participants.
Specialised workshops:
1. XFEL data acquisition and control for photon beam systems, Hamburg, 23 and 24 January 2008; organiser: Chris Youngman; 47 participants
2. Science with and Instrumentation for SQS at the European XFEL, Aarhus, Denmark, 29 to 31 October 2008; organiser: Henrik Pedersen; 36 participants
3. Science with and instrumentation for ultra-fast coherent diffraction imaging of single particles, clusters and bio-molecules at the European XFEL, Uppsala, Sweden, 20 to 22 November 2008; organiser: J. Hajdu, D. van der Spoel; 71 participants
4. High energy density science endstation and associated diagnostics and instrumentation at the European XFEL, Oxford, United Kingdom, 30 March to 1 April 2009; organiser: Justin Wark; 69 participants
5. Spectroscopy and coherent scattering endstation and associated instrumentation at the European XFEL, PSI Villigen, Switzerland, June 2-4, 2009; organiser: Rafael Abela, Bruce Patterson; 81 participants
6. Materials imaging and dynamics instrument at the European XFEL, MID Grenoble, France, 28 and 29 October 2009; organiser: Anders Madsen; 71 participants
7. Science and instrumentation at the European XFEL: Femtosecond x-ray experiments (FXE), Budapest, 9 to 11 December 2009; organiser György Vankó, Dénes L. Nagy; 115 participants
8. Special x-ray diagnostics and scientific applications of the European XFEL, Ryn, Poland, 14 to 17 February 2010; organiser Robert Nietuby; 62 participants
9. Soft x-ray science and instrumentation at the European XFEL, Trieste, Italy, 16 and 17 December 2010; organiser: Maya Kiskinova and Fulvio Parmigiani; 112 participants.
Schools for young scientists:
1. International school for young scientists: Advanced research in photon sciences, Experimental capabilities of the European XFEL, Moscow, 11 to 13 November 2009
2. XFEL information day: Winter school of synchrotron radiation, Liptovski Jan, Slovakia, 1 to 4 February 2011.
Legal and organisational results
In June 2007 (at the start of the PRE-XFEL contract) the European XFEL project had a sound scientific and technical basis in the TDR and in the validation of the basic technologies by the FLASH facility; from the legal and organisational point of view, the memorandum of understanding (MoU) provided a basis for the work of the European project team in Hamburg, as well as a way forward for the preparation of all financial agreements and legal papers to be provided for a final decision by the interested countries to end the preparation phase and start the project: an International Steering committee (chaired by H. Schunk and later by J. Wood), with one representative of each country having signed the MoU, was in charge of the process, assisted by an administrative and funding issues working group (chaired by H.F. Wagner) and by a science and technical issues working group (chaired by F. Sette).
The actual signing of the 'Convention concerning the construction and operation of a European x-ray free-electron laser facility' took place on 30 November 2009. The period up to this date was occupied by the definition and the legal formulation of the whole organisational and governance structure; the period after this date was occupied by the implementation of this abstract structure and, so to speak, by bringing it to life, with the people and the full activity of a working international research institute.
Legal form and organs
The legal form chosen for the new institution is that of a non-profit limited liability company (GmbH) under German private law; the shareholders are institutions (most frequently public research institutions) of the participating countries.
The organs of the company are the council (assembly of the shareholders) and the management board.
The council is the highest supervisory body of the company, that has the ultimate decision on all important questions in the life of the company, as listed in the 'articles of association' annexed to the convention, among which are: admission of new shareholders; share capital increases; mergers or splits of the company; dissolution of the company; the financial rules of the company; the repartition scheme of operating costs; medium-term scientific programme; annual budget and medium-term financial estimates; appointment, employment and termination of the appointment of the directors (members of the management board); establishment of committees and their terms of reference.
Since the formal establishment of the company (September 2009), the council has met eight times, including the 'foundation' meeting in front of the notary on the day the company was created by the then unique shareholder, DESY. The chairman of the council is Robert Feidenhans'l, of the University of Copenhagen, Denmark. The vice-chairman is Pavol Sovak, of the P.J. afárik University, Koice, Slovakia. The secretary of the council is Stephanie Suhr (European XFEL).
At the time of this writing, the shareholders are:
1. Danish Agency for Science, Technology and Innovation (DASTI), Denmark
2. DESY, Germany
3. National Office for Research and Technology (NKTH), Hungary
3. Andrzej Soltan Institute for Nuclear Studies (IPJ), Poland
4. Russian Corporation of Nanotechnologies (Rusnano), Russia
5. Slovak Republic, represented by the Ministry of Education, Slovakia
6. Vetenskapsrådet (VR), Swedish Research Council, Sweden
7. Swiss Confederation, represented by the State Secretariat for Education and Science, Switzerland.
Pending ratification and/or internal procedures, the designation of the shareholders representing France and Italy (that signed the convention) is expected in the next few months; Spain is expected to sign the convention in the autumn of 2011 and to nominate the corresponding shareholder after that.
The management board of the company is composed of at least two managing directors and additional scientific/technical directors, collectively called 'directors'. Among the managing directors, one shall be a scientist and at the same time the chairperson of the management board; another one shall be an administrative director. The division of responsibilities among the directors is established by the council, in the rules of procedure for the management board.
The management board is composed of Massimo Altarelli (Chair) and Karl Witte (administrative director), who are the managing directors; Serguei Molodtsov andreas Schwarz and Thomas Tschentscher are scientific directors.
The management board meets weekly and the managing and scientific directors are closely interacting in all decision processes.
The council is assisted in its supervisory role by committees. Two of them are explicitly foreseen by the articles of association, the scientific advisory committee (SAC) and the machine advisory committee (MAC), with the task to advise the council and the management board on matters of importance respectively related to the scientific program of the facility and to the accelerator complex. The 15 member SAC is chaired by G. Faigel and the 10 member MAC by M. Eriksson. The membership of the two committees is listed here:
1. SAC: Gyula Faigel (RISSPO Hungary) chairman, Salvador Ferrer (ALBA, Spain) vice chairman, Rafael Abela (Paul Scherrer Institute, Switzerland), Patrick Audebert (École Polytechnique, France), Dimitrios Charalambidis (Foundation for Research and Technology, Greece), Jerome Hastings (SLAC, Stanford, United States of America), Krystina Jablonska (Polish Academy of Sciences, Warsaw, Poland), Sine Larsen (University of Copenhagen, Denmark), Joseph Nordgren (University of Uppsala, Sweden), Vladislav Ya. Panchenko (Institute on Laser and Information Technologies, Russia), Franz Pfeiffer (Technical University Munich, Germany), Aymeric Robert (LCLS, Stanford, United States of America), Karel Saksl (Slovak Academy of Sciences, Slovak Republic), Francesco Sette (ESRF, Grenoble, France) and Edgar Weckert (DESY, Hamburg, Germany).
2. MAC: Mikael Eriksson (MAX-lab, Lund) chairman, Hans-Heinrich Braun (Paul Scherrer Institute, Switzerland), Paul Emma (LCLS/SLAC, Stanford, United States of America), Massimo Ferrario (INFN, Frascati, Italy), Jacek Krzywinski (SLAC, Stanford), Gennady Kulipanov (Budker Institute of Nuclear Physics, Russia), John Mammosser (Jefferson Lab, Newport News, United States of America), Alban Mosnier (CEA, Saclay, France), Felix Rodriguez Mateos (CERN/ITER, Switzerland/France), Richard Walker (Diamond, Oxfordshire, United Kingdom).
Other important committees of the European XFEL are the administration and finance committee (AFC) and the in-kind review committee (IKRC). Unlike the SAC and MAC, however their membership is composed of members designated by each participating country, up to two per country for the AFC, one for the IKRC; two additional members of IKRC are designated by the European XFEL management board, to represent the company.
The AFC has the task, among others, to examine the budget estimates, the annual accounts and the year-end auditors' report and to inform the council thereof. More generally it expresses recommendations to council on all administrative and financial matters of importance.
The function of the IKRC will be made clear soon, after clarifying the role of In-kind contributions in the financial structure of the European XFEL.
Financial aspects of the project
In the convention, for each signatory country a figure appears, which corresponds to the contribution of the country to the construction costs. The figure is expressed in 2005 Euros, with the understanding that payments in years later than 2005 have to be corrected for inflation by the 'Eurostat industry producer index', referred to January 2005 as a basis. In reality the situation of the commitments of individual countries already evolved, as for example Sweden announced the increase of its contribution from 12 to 16 million and Spain, that did not yet sign the convention, is going to do it, but with a commitment reduced from 21.6 to 11 million. Therefore the present situation of financial commitments in 2005 Euro is 11.0 million by the Kingdom of Denmark, 36.0 million by the French Republic, 580.0 million by the Federal Republic of Germany, 4.0 million by the Hellenic Republic, 11.0 million by the Republic of Hungary, 33.0 million by the Republic of Italy, 21.6 million by the Republic of Poland, 250.0 million by the Russian Federation, 11.0 million by the Slovak Republic, 11.0 million by the Kingdom of Spain, 16.0 million by the Kingdom of Sweden and 15.0 million by the Swiss Confederation.
Some countries participating in the MoU, like China and the United Kingdom, eventually declined to sign and withdrew their expected contributions. This, together with the costs for the underground construction, which were considerably higher than expected as a result of the general market situation in 2007 and 2008, introduced a financial pressure on the project. The major shareholders are very actively pursuing a solution to this problem and it is expected that it will soon be found.
As we mentioned before, the contribution committed by each country can be paid under two forms: either as a direct cash transfer, or as an in-kind contribution, defined as a non-cash benefit transfer of:
1. a technical component, as well as the personnel needed for its installation and integration on site, or
2. personnel made available for specific tasks during the construction phase.
Many countries expressed a strong interest in contributing in-kind to the facility. In fact, in-kind contributions allow to spend the money in the country of origin and are therefore more welcome by political authorities; allow home laboratories to be directly involved and therefore to acquire experience and know-how in very advanced fields of technology; ensure that young scientists undergoing training are exposed to the frontiers of research and of instrumentation without having to leave the country.
In-kind contributions make up more than 50 % of the total pledged contribution; even more if we consider that, for internal administrative reasons, Russian laboratories prefer to have a different contractual formulation for the components they could deliver in-kind. Notably, France and Italy deliver the total of their contribution in-kind.
The process leading to allocation of an in-kind contribution to a partner country starts with a consultation between a laboratory in a partner country and the leader of a work package (WPL), or the responsible director (WPR); after a sufficiently precise idea about the component specifications, the implementation schedule, the value of the in-kind contribution is agreed, the concerned laboratory submits an expression of interest, which is then transmitted to the in-kind review committee. This committee recommends allocation of the in-kind contribution after examination of the suitability of the proposed delivery for an in-kind contribution, the competence and experience and of the proposing laboratory in the necessary technologies and the financial value of the contribution in relation to the cost-book of the facility. After this scrutiny, if the IKRC recommends allocation, the allocation is approved by the management board if the value is below one million and transmitted for approval to the AFC if the value exceeds one million but is below five million. The council takes note of the decisions of the management board or of the AFC, or, in case the value exceeds five million, it takes the final decision on the allocation. The detailed in-kind contribution agreement, where all technical specifications, milestones, intermediate and final deliverables and crediting schedule is then prepared and submitted again to the management board, the AFC or council, depending on the value of the contribution as in the case of the allocation.
The definition of this whole procedure, the staffing of the in-kind contribution office with a very experienced engineer and support personnel were among the most significant results of the PRE-XFEL contract.
Potential impact:
The main objective of the PRE-XFEL contract was to accelerate and facilitate the creation of the European x-ray free-electron laser facility. In order to assess the potential impact it is therefore necessary to assess the impact of the facility itself on the relevant stakeholders.
The stakeholders of the European XFEL can be classified into the following categories:
1. European Community's (EC) research directorate, ESFRI
2. National government research funding agencies
3. academic community: universities, research centres, scientists, etc.
4. European industry and more generally, economic and financial institutions.
The objectives of these different categories of stakeholders can be identified as follows:
1. EC Research Directorate, ESFRI: promotion of the ERA, promotion of excellence in research and innovation in Europe; promotion of international mobility of researchers within Europe; reduce brain drain to United States of America and other extra-European destinations.
2. National government research funding agencies: increasing number of publications and visibility of their scientific community, other objectives of their national research and innovation plan.
3. Academic community: universities, research centres, scientists, etc.: opportunities for training and placement of graduates; open access to state of the art facilities for European academics.
4. European industry and more generally, economic and financial institutions: increase technological knowhow; support in competition for high technology products market.
For each stakeholder group, suitable indicators are identified to assess the impact of the European XFEL in terms of the stakeholders' objectives.
For the first stakeholders' group, we note that:
1. the European XFEL has provided Europe with a unique facility, which is expected not only to match, but actually to exceed the capabilities of comparable United States and Japanese facilities, in particular in terms of number of pulses and therefore of photons per second.
2. the European XFEL has strived from the very beginning for a Europe-wide recruitment of scientists. Here the PRE-XFEL grant was very important because it involved beneficiaries in many countries in the process at a very early stage. This is easily quantified by observing the distribution by nationality of the recruited scientific and engineering personnel.
3. the indicators for the brain drain objective has an easily established component, given by simply counting the number of recruits previously employed outside of Europe (essentially in the United States of America). There are five people who moved to Europe to accept a European XFEL job. Out of a total 63 science and engineering positions this does not look very impressive. However one should add (and this is not so easy) how many of our recruited people, especially the youngest, would have accepted an offer in the United States, had they not had the opportunity to come to the European XFEL. Here the evidence cannot be other than anecdotal and incomplete, but some cases certainly exist.
For the second stakeholders' group we note that, given the international composition of our scientific staff, one could trace back the nationality of the authors of each publication and provide a 'national' projection of the scientific productivity. To this one could also add the non-XFEL authors, given the frequent collaboration with laboratories all over Europe. We refrain from such exercise, as we consider that the number of publications during the construction phase is not the really relevant number; the real impact of the facility shall be measured by the scientific publications output during the operations phase, when groups of users from the participating countries will come in large numbers to the European XFEL.
For the third stakeholders' group, we note the following:
1. the age distribution of the recruitment by the European XFEL shows a large presence of the younger generations. The European XFEL, having yet to climb from the 90 employees it has at the time of this writing to a total of 237, will continue to provide opportunities of employment for young scientists and engineers, offering post graduate training in a stimulating atmosphere and in a very advanced project.
2. the aim of the project is to implement the most brilliant hard x-ray source in the world and to open it to the academic communities of Europe on the basis of scientific merit, at no cost to the users. This should open very exciting perspectives for scientists in the universities and public research institutes.
Turning now to the fourth group of stakeholders, we can observe that the European XFEL offers to European industry the possibility to acquire experience in the production of extremely advanced and novel high technology products. This could potentially provide them with a head start in markets that may open up in the near future. Two examples may be sufficient. The first one concerns the series fabrication of superconducting niobium cavities for the linear accelerator. Here DESY has over the last decades developed the state of the art of this technology, showing how quality in surface and interface treatment is essential for ensuring high acceleration gradients. However, the almost 2 km long linear accelerator needs 800 cavities and such a massive production can only be organised in industry. The transfer of the knowhow from the research laboratory to the industrial companies took some years of prototype development, qualification exercises and pre-series deliveries; the European industries that are so qualified can now expect to be on the front line for further superconducting accelerators, like the European Spallation Source (ESS) or, if it will be built, a very high energy linear collider for elementary particle physics. The second example is the need to push the technology in order for the European XFEL scientists and users to be able to take advantage of the very high number of pulses per second. This requires, among other R&D projects, the development of position sensitive detectors with very fast read out. Here again academic research and industrial competence come together because the special application specific integrated circuits (ASICs) are designed in academic laboratories, but need fabrication devices available only in industry for their actual deployment. Here again European semiconductor companies may get a head start in a new and promising niche of microelectronics.
The dissemination activities during the project period have been based on three pillars:
1. interaction with and information of the scientific community,
2. interaction with and information of the policy makers and
3. interaction with and information of the general public, with a special focus on the neighbourhood of the construction site.
Four users' meetings and nine specialised workshops have been conducted in the within the project. Additionally, various scientific posters have been presented at conferences and workshops related to the science involved in the project. Moreover, various general events like the 'First and second tunnel and borer christening' or the setup of info points have been one communication channel. These information activities have been supported by the production of flyers, brochures, film and photo footage explaining the European XFEL project and depicting the construction activities. In addition, alongside the project there have been various press releases and press clippings focussed on scientific and non-scientific media.
List of websites:
'http://www.xfel.eu'
The objectives of the preparatory phase of the European x-ray free-electron laser facility, a research infrastructure of the European Strategy Forum for Research infrastructures (ESFRI) roadmap, were the promotion and the acceleration of all processes necessary to transform this strategic scientific proposal into a working research institute, organised to build and operate one of the most innovative scientific instruments worldwide: a source of ultra-short and very bright flashes of coherent x-rays, able to disclose not only the atomic configuration of materials and molecules, but also the atomic dynamics, i.e. its evolution in time during chemical reactions and phase transformations.
At the end of the PRE-XFEL period that lasted from 15 June 2007 to 15.06.2011 there is:
1. an intergovernmental convention (30 November 2009) establishing the European x-ray free-electron laser facility, signed by representatives of 11 governments and including annexes detailing technical and administrative specifications;
2. a limited liability company under German law, the European x-ray free-electron laser facility GmbH (European XFEL), created on 28 September 2009, with research institutions of the participating countries as shareholders, with over 80 employees actively engaged in the construction of the facility and a fully operational management structure and overseeing committees, according to the best governance standards of international research institutions in Europe;
3. a vast international effort to contribute to the construction of the facility. On the one hand, many laboratories from the participating countries are contributing in-kind vital components of the linear accelerator, of the undulator systems (the devices producing the ultra-short bursts of coherent x-rays) and of the photon beamlines and instrumentation systems; on the other, the potential scientific use of the facility after 2015 has been discussed with the community in a series of general users' meetings and thematic workshops, taking place in eight different countries, as well as in schools for young scientists and information days, involving thousands of scientists in the process.
The project is therefore well on its way to its implementation and to the realisation of its ambitious scientific goals.
Project context and objectives:
The history of European collaboration in science and in particular in the establishment of large research infrastructures, can boast remarkable successes such as Organisation Européenne pour la Recherche Nucléaire (CERN), Institut Laue-Langevin (ILL), European Synchrotron Radiation Facility (ESRF), European Organisation for Astronomical Research in the Southern Hemisphere (ESO), to name just a few among many. Nonetheless, the actual process leading from a brilliant scientific concept to a functioning international institution is long and difficult. Some of the main steps and hurdles are:
1. to organise an international scientific consensus on the necessity of the project;
2. to identify and obtain agreement on a site for the proposed facility;
3. to convince a government or an initial core group of governments to spearhead the initiative and to pursue the effort to create the new facility;
4. to secure initial funding for the establishment and support of committees and of a core technical and scientific group in charge of the full design and costing proposal;
5. to facilitate the convergence of financial agreements and cost repartition among the potentially interested countries to secure the financing of the new institute;
6. to reach agreement on the governance, legal and administrative texts lying at the heart of the founding document (convention).
The initial concept of the European x-ray free-electron laser facility was developed in the last decade of the past century, by an international collaboration centred at the Deutsches Elektronen-Synchrotron (DESY) laboratory in Hamburg. The scientific case merges two highly successful achievements of modern physics in providing instruments that benefit all natural sciences: synchrotron light sources on the one hand and ultra-fast (femtosecond) lasers on the other. Synchrotron rings have proven themselves as extremely brilliant sources of x-rays, an electromagnetic radiation with a wavelength comparable to the size of atoms, or to the distance between atoms in matter under normal conditions. This makes them the ideal probe to investigate (one could say 'to see') the atomic structure of matter, i.e. the detailed arrangement in space of the atoms constituting a solid material or a biological molecule. Lasers, in their 50 years of history, have made tremendous progress and are today available for a variety of applications in science and industry. Great strides have in particular been made in the production of intense and extremely short pulses: femtosecond (fs) lasers are available commercially and many laboratories are developing and using attosecond (as) pulsed lasers for scientific purposes. These ultra-short pulses are very useful to investigate the dynamics of chemical reactions or of relaxation and phase transformation processes. Since the typical time scale of atomic motion in such processes is a picosecond (ps), flashes of fs duration can provide snapshots in which atoms are caught in their instantaneous positions. Lasers however produce wavelengths in the visible, infrared or ultraviolet, which are many thousands of times longer than atomic distances and therefore unsuitable to explore the atomic structure of matter - although they have proven of revolutionary importance in other areas of science. A free-electron laser (FEL), based on a high-energy electron accelerator, can produce radiation in pulses as short as a few fs and, at the same time, with a wavelength comparable to the atomic distances.
Worldwide scientific interest in such tools is enormous. X-ray FEL projects are vigorously pursued in the US, in Japan, in South Korea and of course in Europe. The European x-ray free-electron laser facility has a formidable advantage in comparison with all other competitors: its linear accelerator exploits the superconducting accelerator technology, which allows production of many thousands of pulses per second (27 000 is the design value); competing facilities have typically 120 pulses per second, or less.
In 2003 the German government announced its intention to go ahead with the realisation of the project as an international one, in which at least 40 % of the financial resources had to come from foreign sources. Following intense consultations, a memorandum of understanding was signed, in 2004 and 2005, by representatives of China, Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. As an implementation of the memorandum, the European XFEL project team was appointed and installed at DESY in Hamburg, in late 2005, to prepare the foundation of an independent research organisation that will build and operate the European XFEL, i.e. the European XFEL GmbH. The application for the building permit, submitted to the competent German authority in April 2005, was approved in July 2006; a few days later, the European XFEL project team handed over the technical design report (TDR) for the European XFEL to the chairman of the international steering committee, the main decision body foreseen in the memorandum of understanding. The 600 pages thick TDR has over 300 authors, from 71 institutes in 17 countries.
The project took a further step forward when 260 scientists from 22 countries came to Hamburg to participate in the first European XFEL users' meeting, on 24 and 25 January 2007. The main topics of discussion were the requirements of the future users as input for the detailed planning of the experimental stations, the development of novel detectors and experimental techniques.
On 5 June 2007, the German federal minister of education and research, Dr Annette Schavan, in presence of the Russian and French ministers of research, of the presidents of the regional governments of Hamburg and Schleswig Holstein and of other high officials, launches the European XFEL. Germany and the participating countries agree to begin the construction of a 'start version', a facility with slightly less design margins in the linear accelerator, 3 (instead of 5) undulators and photon beamlines and 6 (instead of 10) experimental stations.
At this point, it seemed to many that the signature of the intergovernmental convention, the official creation of the European XFEL company and the first steps of the newly born European research infrastructure would be only a few months away.
In this context, in June 2007 the Pre-XFEL contract started. Its objectives were:
1. the completion of the legal texts (convention, articles of association, bylaws for the new research institute, etc.)
2. the drafting of procedures and rules for the in-kind contributions to the facility to be built
3. the acceleration of the build-up of the staff, in particular scientists and engineers, in order to allow immediate start of design and construction work, even before completion of the formal founding steps
4. a strong programme of outreach to the natural sciences communities in Europe, to involve them in the formulation of a robust scientific program and in the indispensable research and development (R&D) work for the development of suitable instrumentation.
The idea was to use the contract resources in the most efficient way as a catalyst for the rapid take-off of all aspects of the project. Thanks to the support from the contract, a large number of committee meetings and actions for the achievement of objectives one and two were possible; objective three was pursued by using the PRE-XFEL contract resources to support employment of personnel by beneficiary laboratories and by subsequent detachment to the project team in Hamburg. This made the achievement of a team of extremely motivated, enthusiastic young scientists and engineers possible at an early stage and supported also the build-up of the necessary infrastructure to start work. Legal and administrative staff to support objectives one and two was also put in place at an early stage. Objective four was pursued with the organisation of specialised meetings and workshops devoted to specific experimental techniques or components of instrumentation and of general information meetings. Thousands of scientists throughout Europe were involved in these activities.
Project results
The European x-ray free-electron laser facility GmbH was created in 29 September 2009 by DESY as the only shareholder; on 30 November 2009 the signature of the intergovernmental 'Convention concerning the construction and operation of a European x-ray free-electron laser facility' in Hamburg, provided the basis for shareholders of the other participating countries to join. The participating countries that signed the Convention so far are, in alphabetic order: Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovakia, Sweden and Switzerland. Spain was expected to sign in autumn of 2011.
At the end of the PRE-XFEL contract, the project is in full swing into the construction phase. A new international European research infrastructure has come to life, its technical implementation is well under way and a well-developed governance system is in place. This is the main result of the PRE-XFEL contract and it shall be illustrated in detail in the following. For clarity and convenience, it is useful to separate the milestones achieved in the scientific/technical implementation of the project, on the one hand, from the legal, organisational and governance structures that have been defined and set up, on the other.
Scientific and technical results
Civil construction activities
Starting on the DESY campus, a nearly 2 km long linear accelerator imparts a 17.5 GeV energy to electrons; the highly accelerated electrons are then sent through undulators, systems of magnets which force the electrons to a zig-zag trajectory and generate intense bursts of coherent x-rays. The electrons are then stopped against large copper and graphite cylinders, while the x-ray bursts are channelled through long (up to about 1 km) photon beamlines to the experimental hall, 3.4 km away from the electron starting point on the DESY campus. All of the buildings so far described are underground, at a depth varying between 6 and 28 m below the surface. Only an office and laboratory building above the experimental hall and the access buildings above the other shafts are above the ground. Accelerator components, undulators and photon beamlines are in tunnels with a diameter of about 5.5 m; the total length of tunnels is 5.7 km.
Civil construction activities started in January 2009, in three separate building sites, corresponding to major shafts: one on the DESY Bahrenfeld campus, the second in Osdorfer Born and the third in Schenefeld, where the Experimental Hall is located. Actual work in the field started on 8 January 2009, with some preparatory work starting even earlier, in December 2008. Preparatory work included modification or construction of access roads, removal of trees and other vegetation where needed, installation of construction site offices, displaying construction site panels, fencing, installing water and power access, performing search for explosives and setting up concrete (Schenefeld and Bahrenfeld) and bentonite facilities.
At the DESY-Bahrenfeld site, 110 000 m3 soil of the Lise-Meitner-Park were removed and the excavation of the 34 m deep and 1 500 m2 sized watertight building pit for the injector complex was started, with 80 000 m3 removal of soil. The excavation there was completed in late 2010 and the construction of the injector building, with seven stories from the bottom of the shaft up to the ground level, started. In June 2011, the concrete structure of the building was completed and the roof is now visible above ground level.
Similarly work started and progressed rapidly also in the Osdorfer Born site. In Schenefeld, excavation of the 90 X 50 m2 hall and of the smaller shafts corresponding to the branching points of the undulator tunnels (XS2, XS3, XS4) also progressed essentially according to schedule.
In July 2010 the first tunnelling machine started the digging of the tunnels connecting the shafts and was joined by a second one in December 2010.
In June 2011, at the end of the PRE-XFEL contract, 3 km of tunnels were already excavated and the completion of the main linear accelerator tunnel XTL was only a few weeks away. The progress of the tunnelling works can be followed in real time via a public web page (http://www.xfel.eu/project/construction_progress/(odnośnik otworzy się w nowym oknie)) accessible from the home page of the XFEL project (http://www.xfel.eu/)(odnośnik otworzy się w nowym oknie); details about the current and past activities of the two tunnel machines can be found there.
Thanks to the PRE-XFEL support, it was possible to create, staff and put to work an international project team ahead of the creation of the company and, making full use of German funds channelled via DESY, to start the civil engineering work after the June 2007 decision to go ahead with the project. In this way, the delay in achieving foundation texts agreed by all partners was not entirely reflected on a project delay.
Development and construction of the accelerator
In the general organisation for the construction of the European XFEL, the construction of the linear accelerator is entrusted to the 'accelerator construction' consortium, a group of 15 laboratories from the participating countries, coordinated by DESY and is going to be delivered to the European XFEL company as an in-kind contribution. This may look at first as a complex and risky strategy, were it not for the fact that most of the laboratories involved in the consortium have worked together for many years in the development of the superconducting 'TESLA' technology and in the construction of the accelerator for the FLASH vacuum ultraviolet (VUV) and soft x-ray FEL operating in Hamburg since 2004; FLASH, besides being a very successful user facility on its own, can also be regarded as a large scale validation prototype for the European XFEL. The laboratories involved in the consortium are:
1. DESY, Hamburg and Zeuthen, Germany (coordinator)
2. Atomic Energy Commission (CEA) Saclay, France
3. Centre national de la recherche scientifique, Laboratoire de l'Accélérateur Linéaire (CNRS-LAL) Orsay, France
4. Istituto Nazionale di Fisica Nucleare (INFN) Milano, Italy
5. Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid, Spain
6. Soltan Institute, Swierk, Poland
7. University of Wroclav, Poland
8. Institute of Nuclear Physics (IFJ-PAN), Cracow, Poland
9. Budker Institute, Novosibirsk, Russia
10. Institute for High Energy Physics (IHEP), Protvino, Russia
11. Institute for Nuclear Research (INR), Troitsk, Russia
12. Efremov Institute, Saint Petersburg, Russia
13. University of Stockholm, Sweden
14. University of Uppsala, Sweden
15. Paul Scherrer Institute, Villigen, Switzerland.
The cryomodule contains components built or procured by DESY, INFN Milano, LAL Orsay, CIEMAT Madrid, Soltan Institute in Swierk; the cryomodules are going to be assembled in a facility set up in Saclay by CEA and tested in Hamburg in the accelerator module test facility (AMTF), a large hall built by DESY, with cryogenic and radio frequency (RF) equipment built in a German-Polish-Russian collaboration; all cryomodules shall undergo such testing before being installed in the tunnel. The production of this large series of cryomodules and of their components (among which are over 800 high quality superconducting niobium radio-frequency cavities) is a major challenge for industry as well. A substantial amount of know-how was transferred to industry during the qualification and tendering exercises.
As it is the case for most of the components of the European XFEL accelerator, the cryomodules design is based very heavily on the FLASH corresponding components, with modifications inspired by the several years of careful monitoring of the performance during operation of that facility. The same holds for the injector, the system that imparts the first acceleration to the electrons emitted from the photocathode in the electron gun and impresses a high collimation and very tight transverse section on the electron bunches, to be preserved as much as possible along the whole acceleration chain, a crucial requirement for the lasing process that shall take place more than 2 km downstream, when the electrons radiate in the undulators. The injector for FLASH and presently the one for the European XFEL have been developed by DESY in its Zeuthen and Hamburg labs.
Development and construction of undulators
The accelerated electron bunches emerging from the long linear accelerator are sent through the undulators, where they are subjected to magnetic fields pointing in alternate directions, which force the electrons to follow a zig-zag trajectory and radiate; if the quality of the electron bunches and of the undulators is sufficient, the emitted radiation consists of bursts of coherent x-rays. Three undulators are foreseen for the 'start-up' version of the European XFEL and they range in length from about 100 to 180 m. Two, called SASE1 and SASE2 are specialized for the production of hard x-rays, whereas the third one, SASE3, is devoted to the production of soft x-rays. The quality of the electron bunches is given, as explained in the previous section, by their collimation and tight transverse section; the quality of the undulators by the accurate periodicity of the magnetic fields. undulators are composed, in the design chosen for the European XFEL, of 5 m segments, each of which contains a lower and an upper array of permanent magnets, separated by a gap of the order of a cm, that should be adjustable, in order to tune the wavelength of the emitted radiation. The perfect parallelism and the precise identical separation (down to µm level) of the upper and lower arrays in all the segments are needed for the required field quality. This level of mechanical precision is a formidable engineering problem, as the magnetic forces between the upper and lower magnet arrays are gigantic and the frames are therefore vey bulky mechanical supports. Here again the experience from FLASH is very useful, although the tolerances for longer wavelengths (VUV and soft x-rays) are more relaxed, the total length of the FLASH undulator is about 30 m and the gap between the magnet arrays is fixed and not tuneable.
At the end of the PRE-XFEL contract, that supported engineering recruitments for the Undulator group at an early stage, two generations of 5 m segment prototypes had been delivered, the second generation being tested in the undulator labs at the time of this writing. After evaluation of the prototypes, orders for the series production will be tendered out, with an increased confidence level on the quality of the resulting products.
In between undulator segments, 'intersections' are foreseen, where sensitive instruments are used to measure and to correct electron trajectories for optimisation of lasing properties. These are being developed and built with the help of Swedish and Spanish in-kind contributions.
Photon beamlines and diagnostics
After the x-ray pulses are produced in the undulators, they must be transported to the Experimental Hall, without degrading their quality, analyzed to determine their exact properties, which may be very important to evaluate the experimental results and, if needed, filtered or modified. For example, some experiments may need a very narrow interval of wavelengths, which is achieved by a monochromator; other experiments may need a focused beam and therefore require optical devices such as curved mirrors, or Fresnel zone plates. All of the necessary or desirable components must be especially designed and built, to be adapted to the unprecedented properties of x-ray laser-like beams. The transport and the conditioning of the pulses is the task of the optics group; the analysis of the properties of the pulses is the task of the photon diagnostics group. Both groups took great advantage of the PRE-XFEL grant to ensure the recruitment of the necessary scientific and engineering staff, starting already in 2007; the milestone foreseeing viable optical and diagnostics components installed in 2015 is very demanding; but it would have been absolutely untenable without this early start.
In April 2011, the optical layout for the photon beamlines was the object of a conceptual design review by the scientific advisory committee, which gave a positive opinion about the timeline, the assessment and the handling of technical risks. The diagnostics work package is also showing good progress and design of appropriate devices is under way at the European XFEL and via collaborations with DESY and with the Joint Institute for nuclear research in Dubna, Russia. In February 2010 a specialized workshop devoted to 'X-ray diagnostics and scientific application of the European XFEL', supported by PRE-XFEL grant, was held in Ryn, Poland. The over 60 attendants had an opportunity to contribute to the specifications of the diagnostics system.
Experimental stations
The three undulators foreseen in the initial phase of the European XFEL send photon pulses down the corresponding photon beamlines, which end in the experimental hall. Here six experimental stations (or 'instruments') are located, as every beamline can feed alternatively two instruments (for example, switching the beam between them every 12 hours, or with whatever timing is best suited to the users). Each instrument is devoted to a well-defined experimental technique, or to a special scientific domain. The definition and specification of the six instruments was the object of a vast consultation with the scientific community, as six of the altogether nine workshops organised with support of the PRE-XFEL grant were each devoted to one of the six instruments; actually the seventh one was also devoted to the two instruments served by the soft x-ray undulator. Since the attendance to each workshop was between 35 and 115 participants and each was held in a different country, to facilitate a good national balance in the participation, the claim of a wide consultation with the scientific community is well founded. A good age distribution was also aimed at, by granting PRE-XFEL travel support funds to young scientists.
At present, individual instruments are undergoing conceptual design reviews by the scientific advisory committee. The first two, namely small quantum systems (SQS) and femtosecond x-ray experiments (FXE) were reviewed in April 2011.
Detectors are important components of all experimental stations and deserve special mention here. One of the conditions for the success of the European XFEL is going to be the ability to use the uniquely high number of x-ray pulses per second generated by the FEL, based on a superconducting Linac. One crucial element of the strategy to implement this goal is the development of detectors with appropriate time-response characteristics, in particular capable of distinguishing x-ray pulses separated by as little as 220 nanoseconds. This requirement is especially challenging for area detectors, with typically millions of pixels.
This is why three separate ambitious projects for area detectors were solicited from international consortia of laboratories with world class reputation in detector development, as a result of an open call for expressions of interest. The three detectors under development, besides the mentioned response time requirements, have dynamic ranges, noise levels, spatial resolution, etc., properties that make each of them best suited for a particular class of experiments. In this sense, the success of all of them would not produce redundancy and would not correspond to an inefficient use of resources, quite the opposite being true. The proposals from the three consortia were selected with the help of an advisory committee of well-known experts, the so-called detector advisory committee (DAC), which has continued to assist the management board in monitoring the progress of the approved projects. The three projects and the respective consortia are:
1. Large pixel detector (LPD), STFC/Rutherford Appleton Laboratory and University of Glasgow (United Kingdom)
2. DEPMOS Sensor with Signal Compression (DSSC), MPI-Semiconductor Lab, Garching, Germany; University of Heidelberg, University Siegen (Germany); Politecnico di Milano, Università di Bergamo (Italy); DESY, Hamburg
3. Adaptive gain integrating pixel detector(AGIPD), DESY, Hamburg; PSI/SLS (Switzerland); University of Bonn (Germany); University of Hamburg (Germany).
In addition to the independent developments of each project, research on problems common to all detectors, i.e. the effects of intense irradiation on the detector sensors (radiation damage and possible anomalies of the electronic response due to the large amount of charges generated by each pulse) are handled in a common way under the coordination of the European XFEL, in collaboration with the University of Hamburg and other institutes. A computer program was also developed to simulate the expected signal from a given experiment and to compute the corresponding detector performance.
In the case of the LPD project, a complete prototype for testing and calibration could become available in early 2013.
Reaching out to the European scientific community: Workshops, meetings and schools.
One of the most important work packages of the PRE-XFEL contact was devoted to 'Coordination activity on the XFEL users' community'. Here the objective was to mobilise the scientific community to contribute to the shaping of the scientific program of the facility and to the corresponding instrumental developments. This was implemented by organising four general users' meetings in Hamburg and nine specialised workshops around Europe devoted to the six instruments or to other important aspects of instrumentation. In addition some support was also given to special events with strong educational character for young scientists. In the following a list of events with a few key data is given.
General users' meetings:
1. Users' meeting 2008, Hamburg, 23 and 24 January 2008, 252 participants
2. Users' meeting 2009, Hamburg, 28 and 29 January 2009, 256 participants
3. Users' meeting 2010, Hamburg, 27 to 29 January 2010, 281 participants
4. Users' meeting 2011, Hamburg, 26 to 28 January 2011, 319 participants.
Specialised workshops:
1. XFEL data acquisition and control for photon beam systems, Hamburg, 23 and 24 January 2008; organiser: Chris Youngman; 47 participants
2. Science with and Instrumentation for SQS at the European XFEL, Aarhus, Denmark, 29 to 31 October 2008; organiser: Henrik Pedersen; 36 participants
3. Science with and instrumentation for ultra-fast coherent diffraction imaging of single particles, clusters and bio-molecules at the European XFEL, Uppsala, Sweden, 20 to 22 November 2008; organiser: J. Hajdu, D. van der Spoel; 71 participants
4. High energy density science endstation and associated diagnostics and instrumentation at the European XFEL, Oxford, United Kingdom, 30 March to 1 April 2009; organiser: Justin Wark; 69 participants
5. Spectroscopy and coherent scattering endstation and associated instrumentation at the European XFEL, PSI Villigen, Switzerland, June 2-4, 2009; organiser: Rafael Abela, Bruce Patterson; 81 participants
6. Materials imaging and dynamics instrument at the European XFEL, MID Grenoble, France, 28 and 29 October 2009; organiser: Anders Madsen; 71 participants
7. Science and instrumentation at the European XFEL: Femtosecond x-ray experiments (FXE), Budapest, 9 to 11 December 2009; organiser György Vankó, Dénes L. Nagy; 115 participants
8. Special x-ray diagnostics and scientific applications of the European XFEL, Ryn, Poland, 14 to 17 February 2010; organiser Robert Nietuby; 62 participants
9. Soft x-ray science and instrumentation at the European XFEL, Trieste, Italy, 16 and 17 December 2010; organiser: Maya Kiskinova and Fulvio Parmigiani; 112 participants.
Schools for young scientists:
1. International school for young scientists: Advanced research in photon sciences, Experimental capabilities of the European XFEL, Moscow, 11 to 13 November 2009
2. XFEL information day: Winter school of synchrotron radiation, Liptovski Jan, Slovakia, 1 to 4 February 2011.
Legal and organisational results
In June 2007 (at the start of the PRE-XFEL contract) the European XFEL project had a sound scientific and technical basis in the TDR and in the validation of the basic technologies by the FLASH facility; from the legal and organisational point of view, the memorandum of understanding (MoU) provided a basis for the work of the European project team in Hamburg, as well as a way forward for the preparation of all financial agreements and legal papers to be provided for a final decision by the interested countries to end the preparation phase and start the project: an International Steering committee (chaired by H. Schunk and later by J. Wood), with one representative of each country having signed the MoU, was in charge of the process, assisted by an administrative and funding issues working group (chaired by H.F. Wagner) and by a science and technical issues working group (chaired by F. Sette).
The actual signing of the 'Convention concerning the construction and operation of a European x-ray free-electron laser facility' took place on 30 November 2009. The period up to this date was occupied by the definition and the legal formulation of the whole organisational and governance structure; the period after this date was occupied by the implementation of this abstract structure and, so to speak, by bringing it to life, with the people and the full activity of a working international research institute.
Legal form and organs
The legal form chosen for the new institution is that of a non-profit limited liability company (GmbH) under German private law; the shareholders are institutions (most frequently public research institutions) of the participating countries.
The organs of the company are the council (assembly of the shareholders) and the management board.
The council is the highest supervisory body of the company, that has the ultimate decision on all important questions in the life of the company, as listed in the 'articles of association' annexed to the convention, among which are: admission of new shareholders; share capital increases; mergers or splits of the company; dissolution of the company; the financial rules of the company; the repartition scheme of operating costs; medium-term scientific programme; annual budget and medium-term financial estimates; appointment, employment and termination of the appointment of the directors (members of the management board); establishment of committees and their terms of reference.
Since the formal establishment of the company (September 2009), the council has met eight times, including the 'foundation' meeting in front of the notary on the day the company was created by the then unique shareholder, DESY. The chairman of the council is Robert Feidenhans'l, of the University of Copenhagen, Denmark. The vice-chairman is Pavol Sovak, of the P.J. afárik University, Koice, Slovakia. The secretary of the council is Stephanie Suhr (European XFEL).
At the time of this writing, the shareholders are:
1. Danish Agency for Science, Technology and Innovation (DASTI), Denmark
2. DESY, Germany
3. National Office for Research and Technology (NKTH), Hungary
3. Andrzej Soltan Institute for Nuclear Studies (IPJ), Poland
4. Russian Corporation of Nanotechnologies (Rusnano), Russia
5. Slovak Republic, represented by the Ministry of Education, Slovakia
6. Vetenskapsrådet (VR), Swedish Research Council, Sweden
7. Swiss Confederation, represented by the State Secretariat for Education and Science, Switzerland.
Pending ratification and/or internal procedures, the designation of the shareholders representing France and Italy (that signed the convention) is expected in the next few months; Spain is expected to sign the convention in the autumn of 2011 and to nominate the corresponding shareholder after that.
The management board of the company is composed of at least two managing directors and additional scientific/technical directors, collectively called 'directors'. Among the managing directors, one shall be a scientist and at the same time the chairperson of the management board; another one shall be an administrative director. The division of responsibilities among the directors is established by the council, in the rules of procedure for the management board.
The management board is composed of Massimo Altarelli (Chair) and Karl Witte (administrative director), who are the managing directors; Serguei Molodtsov andreas Schwarz and Thomas Tschentscher are scientific directors.
The management board meets weekly and the managing and scientific directors are closely interacting in all decision processes.
The council is assisted in its supervisory role by committees. Two of them are explicitly foreseen by the articles of association, the scientific advisory committee (SAC) and the machine advisory committee (MAC), with the task to advise the council and the management board on matters of importance respectively related to the scientific program of the facility and to the accelerator complex. The 15 member SAC is chaired by G. Faigel and the 10 member MAC by M. Eriksson. The membership of the two committees is listed here:
1. SAC: Gyula Faigel (RISSPO Hungary) chairman, Salvador Ferrer (ALBA, Spain) vice chairman, Rafael Abela (Paul Scherrer Institute, Switzerland), Patrick Audebert (École Polytechnique, France), Dimitrios Charalambidis (Foundation for Research and Technology, Greece), Jerome Hastings (SLAC, Stanford, United States of America), Krystina Jablonska (Polish Academy of Sciences, Warsaw, Poland), Sine Larsen (University of Copenhagen, Denmark), Joseph Nordgren (University of Uppsala, Sweden), Vladislav Ya. Panchenko (Institute on Laser and Information Technologies, Russia), Franz Pfeiffer (Technical University Munich, Germany), Aymeric Robert (LCLS, Stanford, United States of America), Karel Saksl (Slovak Academy of Sciences, Slovak Republic), Francesco Sette (ESRF, Grenoble, France) and Edgar Weckert (DESY, Hamburg, Germany).
2. MAC: Mikael Eriksson (MAX-lab, Lund) chairman, Hans-Heinrich Braun (Paul Scherrer Institute, Switzerland), Paul Emma (LCLS/SLAC, Stanford, United States of America), Massimo Ferrario (INFN, Frascati, Italy), Jacek Krzywinski (SLAC, Stanford), Gennady Kulipanov (Budker Institute of Nuclear Physics, Russia), John Mammosser (Jefferson Lab, Newport News, United States of America), Alban Mosnier (CEA, Saclay, France), Felix Rodriguez Mateos (CERN/ITER, Switzerland/France), Richard Walker (Diamond, Oxfordshire, United Kingdom).
Other important committees of the European XFEL are the administration and finance committee (AFC) and the in-kind review committee (IKRC). Unlike the SAC and MAC, however their membership is composed of members designated by each participating country, up to two per country for the AFC, one for the IKRC; two additional members of IKRC are designated by the European XFEL management board, to represent the company.
The AFC has the task, among others, to examine the budget estimates, the annual accounts and the year-end auditors' report and to inform the council thereof. More generally it expresses recommendations to council on all administrative and financial matters of importance.
The function of the IKRC will be made clear soon, after clarifying the role of In-kind contributions in the financial structure of the European XFEL.
Financial aspects of the project
In the convention, for each signatory country a figure appears, which corresponds to the contribution of the country to the construction costs. The figure is expressed in 2005 Euros, with the understanding that payments in years later than 2005 have to be corrected for inflation by the 'Eurostat industry producer index', referred to January 2005 as a basis. In reality the situation of the commitments of individual countries already evolved, as for example Sweden announced the increase of its contribution from 12 to 16 million and Spain, that did not yet sign the convention, is going to do it, but with a commitment reduced from 21.6 to 11 million. Therefore the present situation of financial commitments in 2005 Euro is 11.0 million by the Kingdom of Denmark, 36.0 million by the French Republic, 580.0 million by the Federal Republic of Germany, 4.0 million by the Hellenic Republic, 11.0 million by the Republic of Hungary, 33.0 million by the Republic of Italy, 21.6 million by the Republic of Poland, 250.0 million by the Russian Federation, 11.0 million by the Slovak Republic, 11.0 million by the Kingdom of Spain, 16.0 million by the Kingdom of Sweden and 15.0 million by the Swiss Confederation.
Some countries participating in the MoU, like China and the United Kingdom, eventually declined to sign and withdrew their expected contributions. This, together with the costs for the underground construction, which were considerably higher than expected as a result of the general market situation in 2007 and 2008, introduced a financial pressure on the project. The major shareholders are very actively pursuing a solution to this problem and it is expected that it will soon be found.
As we mentioned before, the contribution committed by each country can be paid under two forms: either as a direct cash transfer, or as an in-kind contribution, defined as a non-cash benefit transfer of:
1. a technical component, as well as the personnel needed for its installation and integration on site, or
2. personnel made available for specific tasks during the construction phase.
Many countries expressed a strong interest in contributing in-kind to the facility. In fact, in-kind contributions allow to spend the money in the country of origin and are therefore more welcome by political authorities; allow home laboratories to be directly involved and therefore to acquire experience and know-how in very advanced fields of technology; ensure that young scientists undergoing training are exposed to the frontiers of research and of instrumentation without having to leave the country.
In-kind contributions make up more than 50 % of the total pledged contribution; even more if we consider that, for internal administrative reasons, Russian laboratories prefer to have a different contractual formulation for the components they could deliver in-kind. Notably, France and Italy deliver the total of their contribution in-kind.
The process leading to allocation of an in-kind contribution to a partner country starts with a consultation between a laboratory in a partner country and the leader of a work package (WPL), or the responsible director (WPR); after a sufficiently precise idea about the component specifications, the implementation schedule, the value of the in-kind contribution is agreed, the concerned laboratory submits an expression of interest, which is then transmitted to the in-kind review committee. This committee recommends allocation of the in-kind contribution after examination of the suitability of the proposed delivery for an in-kind contribution, the competence and experience and of the proposing laboratory in the necessary technologies and the financial value of the contribution in relation to the cost-book of the facility. After this scrutiny, if the IKRC recommends allocation, the allocation is approved by the management board if the value is below one million and transmitted for approval to the AFC if the value exceeds one million but is below five million. The council takes note of the decisions of the management board or of the AFC, or, in case the value exceeds five million, it takes the final decision on the allocation. The detailed in-kind contribution agreement, where all technical specifications, milestones, intermediate and final deliverables and crediting schedule is then prepared and submitted again to the management board, the AFC or council, depending on the value of the contribution as in the case of the allocation.
The definition of this whole procedure, the staffing of the in-kind contribution office with a very experienced engineer and support personnel were among the most significant results of the PRE-XFEL contract.
Potential impact:
The main objective of the PRE-XFEL contract was to accelerate and facilitate the creation of the European x-ray free-electron laser facility. In order to assess the potential impact it is therefore necessary to assess the impact of the facility itself on the relevant stakeholders.
The stakeholders of the European XFEL can be classified into the following categories:
1. European Community's (EC) research directorate, ESFRI
2. National government research funding agencies
3. academic community: universities, research centres, scientists, etc.
4. European industry and more generally, economic and financial institutions.
The objectives of these different categories of stakeholders can be identified as follows:
1. EC Research Directorate, ESFRI: promotion of the ERA, promotion of excellence in research and innovation in Europe; promotion of international mobility of researchers within Europe; reduce brain drain to United States of America and other extra-European destinations.
2. National government research funding agencies: increasing number of publications and visibility of their scientific community, other objectives of their national research and innovation plan.
3. Academic community: universities, research centres, scientists, etc.: opportunities for training and placement of graduates; open access to state of the art facilities for European academics.
4. European industry and more generally, economic and financial institutions: increase technological knowhow; support in competition for high technology products market.
For each stakeholder group, suitable indicators are identified to assess the impact of the European XFEL in terms of the stakeholders' objectives.
For the first stakeholders' group, we note that:
1. the European XFEL has provided Europe with a unique facility, which is expected not only to match, but actually to exceed the capabilities of comparable United States and Japanese facilities, in particular in terms of number of pulses and therefore of photons per second.
2. the European XFEL has strived from the very beginning for a Europe-wide recruitment of scientists. Here the PRE-XFEL grant was very important because it involved beneficiaries in many countries in the process at a very early stage. This is easily quantified by observing the distribution by nationality of the recruited scientific and engineering personnel.
3. the indicators for the brain drain objective has an easily established component, given by simply counting the number of recruits previously employed outside of Europe (essentially in the United States of America). There are five people who moved to Europe to accept a European XFEL job. Out of a total 63 science and engineering positions this does not look very impressive. However one should add (and this is not so easy) how many of our recruited people, especially the youngest, would have accepted an offer in the United States, had they not had the opportunity to come to the European XFEL. Here the evidence cannot be other than anecdotal and incomplete, but some cases certainly exist.
For the second stakeholders' group we note that, given the international composition of our scientific staff, one could trace back the nationality of the authors of each publication and provide a 'national' projection of the scientific productivity. To this one could also add the non-XFEL authors, given the frequent collaboration with laboratories all over Europe. We refrain from such exercise, as we consider that the number of publications during the construction phase is not the really relevant number; the real impact of the facility shall be measured by the scientific publications output during the operations phase, when groups of users from the participating countries will come in large numbers to the European XFEL.
For the third stakeholders' group, we note the following:
1. the age distribution of the recruitment by the European XFEL shows a large presence of the younger generations. The European XFEL, having yet to climb from the 90 employees it has at the time of this writing to a total of 237, will continue to provide opportunities of employment for young scientists and engineers, offering post graduate training in a stimulating atmosphere and in a very advanced project.
2. the aim of the project is to implement the most brilliant hard x-ray source in the world and to open it to the academic communities of Europe on the basis of scientific merit, at no cost to the users. This should open very exciting perspectives for scientists in the universities and public research institutes.
Turning now to the fourth group of stakeholders, we can observe that the European XFEL offers to European industry the possibility to acquire experience in the production of extremely advanced and novel high technology products. This could potentially provide them with a head start in markets that may open up in the near future. Two examples may be sufficient. The first one concerns the series fabrication of superconducting niobium cavities for the linear accelerator. Here DESY has over the last decades developed the state of the art of this technology, showing how quality in surface and interface treatment is essential for ensuring high acceleration gradients. However, the almost 2 km long linear accelerator needs 800 cavities and such a massive production can only be organised in industry. The transfer of the knowhow from the research laboratory to the industrial companies took some years of prototype development, qualification exercises and pre-series deliveries; the European industries that are so qualified can now expect to be on the front line for further superconducting accelerators, like the European Spallation Source (ESS) or, if it will be built, a very high energy linear collider for elementary particle physics. The second example is the need to push the technology in order for the European XFEL scientists and users to be able to take advantage of the very high number of pulses per second. This requires, among other R&D projects, the development of position sensitive detectors with very fast read out. Here again academic research and industrial competence come together because the special application specific integrated circuits (ASICs) are designed in academic laboratories, but need fabrication devices available only in industry for their actual deployment. Here again European semiconductor companies may get a head start in a new and promising niche of microelectronics.
The dissemination activities during the project period have been based on three pillars:
1. interaction with and information of the scientific community,
2. interaction with and information of the policy makers and
3. interaction with and information of the general public, with a special focus on the neighbourhood of the construction site.
Four users' meetings and nine specialised workshops have been conducted in the within the project. Additionally, various scientific posters have been presented at conferences and workshops related to the science involved in the project. Moreover, various general events like the 'First and second tunnel and borer christening' or the setup of info points have been one communication channel. These information activities have been supported by the production of flyers, brochures, film and photo footage explaining the European XFEL project and depicting the construction activities. In addition, alongside the project there have been various press releases and press clippings focussed on scientific and non-scientific media.
List of websites:
'http://www.xfel.eu'