Periodic Reporting for period 3 - XLS (CompactLight)
Période du rapport: 2021-01-01 au 2021-12-31
Synchrotron light is electromagnetic radiation generated by charged particles that move at a speed near to the velocity of light on a curved path in accelerating machines called synchrotrons. The produced light, which is billion times more brilliant than light generated by conventional light sources, permits a large spectrum of applications in industry as well as basic and applied research in the fields of physics, chemistry, life sciences and medicine, environmental sciences etc. Currently, more than sixty synchrotron light sources are operational worldwide as giant microscopes for the study of matter.
In the last years, a generational leap forward has been made with the implementation of new sources of even more intense electromagnetic radiation, called ‘Free Electron Lasers’ (FELs). These novel machines are based on linear accelerators (Linacs) followed by chains of undulators that force the high-speed electrons on wiggly trajectories, making them emit light. The photon flux emitted by a FEL is several orders of magnitude higher than that produced by today’s synchrotron radiation sources and consists of light pulses that can be extremely short, with a duration of femtoseconds (fs, 10-15 sec) and wavelengths below an Ångström (Å, 10-10 m). These characteristics make the FEL the most powerful instruments for basic research on materials.
Despite the continuously growing demand of ‘beamtime’ from the users, FEL sources are however not likewise distributed as synchrotrons, for technical reasons as well as for the huge investment and operation costs required.
CompactLight (XLS) is a H2020 Design Study funded by the European Union. It started in January 2018 and has a duration of four years. Launched by a group of 22 International Laboratories and two companies it aims to promote the diffusion of FEL light sources at a global scale. The collaboration, coordinated by Elettra-Sincrotrone Trieste, that from April 2020 includes two more partners, brings together experts from the fields of electron sources, Linacs, and the structures required for the production of photons, to work on the ‘Conceptual Design’ of extremely compact FEL sources, with advanced performances and contained costs, in order to permit their implementation also in contexts where the financial resources for research are rather limited.
In the last years, a generational leap forward has been made with the implementation of new sources of even more intense electromagnetic radiation, called ‘Free Electron Lasers’ (FELs). These novel machines are based on linear accelerators (Linacs) followed by chains of undulators that force the high-speed electrons on wiggly trajectories, making them emit light. The photon flux emitted by a FEL is several orders of magnitude higher than that produced by today’s synchrotron radiation sources and consists of light pulses that can be extremely short, with a duration of femtoseconds (fs, 10-15 sec) and wavelengths below an Ångström (Å, 10-10 m). These characteristics make the FEL the most powerful instruments for basic research on materials.
Despite the continuously growing demand of ‘beamtime’ from the users, FEL sources are however not likewise distributed as synchrotrons, for technical reasons as well as for the huge investment and operation costs required.
CompactLight (XLS) is a H2020 Design Study funded by the European Union. It started in January 2018 and has a duration of four years. Launched by a group of 22 International Laboratories and two companies it aims to promote the diffusion of FEL light sources at a global scale. The collaboration, coordinated by Elettra-Sincrotrone Trieste, that from April 2020 includes two more partners, brings together experts from the fields of electron sources, Linacs, and the structures required for the production of photons, to work on the ‘Conceptual Design’ of extremely compact FEL sources, with advanced performances and contained costs, in order to permit their implementation also in contexts where the financial resources for research are rather limited.
The CompactLight FEL has been designed as a hard X-ray facility, covering the wavelength range from 0.8 Å up to 5nm (16 keV to 0.25 keV) with two separate FEL beamlines:
i) a soft X-ray (SXR) FEL able to deliver photons from 5.0nm to 0.6nm (0.25 keV to 2 keV) operating
up to 1 kHz repetition rate (high rep rate);
ii) a hard X-ray FEL source (HXR) ranging from 6.0Å to 0.8 Å (2 keV to 16 keV) with maximum 100
Hz repetition rate (low rep rate).
Key elements proposed in the design are the dual-bunch photoinjector and the two-beam deflectors adopted for the linac. Both give a huge flexibility for the facility operation, with different combinations of SXR and HXR operating modes, at high and low repetition rates, as requested by the users.
Various innovations and advanced systems have been designed specifically for the CompactLight
facility. In particular:
- Electron Source: an innovative dual bunch C-band photoinjector;
- Beam Linearizer: a 36 GHz, Ka-band system with the high power RF source;
- Sub-Harmonic Deflecting System: an S-band (3 GHz) sub-harmonic deflecting structure able to separate the two e-bunches, generated at photoinjector, feeding the two XLS FELs;
- Helical Superconducting Undulator, HSCU.
Each of these innovative systems can also be used ‘stand alone’ in a variety of accelerator applications (i.e. future beam colliders, compact accelerators for medicine, plasma drivers, etc.), where conventional systems cannot meet the challenging performance requested. Moreover they also represent a major opportunity for industrial developments and exploitation.
i) a soft X-ray (SXR) FEL able to deliver photons from 5.0nm to 0.6nm (0.25 keV to 2 keV) operating
up to 1 kHz repetition rate (high rep rate);
ii) a hard X-ray FEL source (HXR) ranging from 6.0Å to 0.8 Å (2 keV to 16 keV) with maximum 100
Hz repetition rate (low rep rate).
Key elements proposed in the design are the dual-bunch photoinjector and the two-beam deflectors adopted for the linac. Both give a huge flexibility for the facility operation, with different combinations of SXR and HXR operating modes, at high and low repetition rates, as requested by the users.
Various innovations and advanced systems have been designed specifically for the CompactLight
facility. In particular:
- Electron Source: an innovative dual bunch C-band photoinjector;
- Beam Linearizer: a 36 GHz, Ka-band system with the high power RF source;
- Sub-Harmonic Deflecting System: an S-band (3 GHz) sub-harmonic deflecting structure able to separate the two e-bunches, generated at photoinjector, feeding the two XLS FELs;
- Helical Superconducting Undulator, HSCU.
Each of these innovative systems can also be used ‘stand alone’ in a variety of accelerator applications (i.e. future beam colliders, compact accelerators for medicine, plasma drivers, etc.), where conventional systems cannot meet the challenging performance requested. Moreover they also represent a major opportunity for industrial developments and exploitation.
The overall concept underlying the project is to bring together recent advances in the main technical FEL sub-systems, i.e. electron photo-injector, linac accelerating structures and undulators, to produce the design of a next-generation facility with significantly lower cost and size than existing facilities. This brings to the use of very low emittance and higher repetition-rate sources, high-gradient linacs, high-efficiency klystrons, improved diagnostics, advanced undulators, the whole facility is being simulated using the most advanced beam dynamics and optimization tools, allowing to design such a cutting-edge facility.
The project will deliver to the scientific community a conceptual design of a machine with unique performance parameters and beam characteristics. The report will also include cost analyses and other strategic documents that support the decision-making process for constructing new facilities, or upgrading existing ones, using CompactLight technologies. The project will furthermore consider the complementary use of the technology for small infrastructures, that can be installed and operated at universities. Project data not affecting the potential exploitation of results by the partners will be made accessible as Open Data to facilitate the use of the technologies.
The major goal of CompactLight is to make the construction and operation of X-ray FELs feasible for smaller countries, regions and universities. This will support their wide-spread availability, reducing oversubscription of existing machines, and creating more and unique research opportunities for the scientific users. Given the large importance of FELs their wide dissemination will have an enormous impact on many different research fields, create access opportunities in more countries, and contribute significantly to European scientific and industrial competitiveness. An important aspect is also the coordinated flow of expertise from Europe’s larger research institutions to the smaller ones with ambitions to engage in cutting-edge photon science.
Major technology areas benefitting from the project are (a) high brightness e-sources (b) rf production and beam acceleration, (c) high-precision diagnostics, (d) undulators and photon production, etc., each of them with large application potential that goes beyond CompactLight and with clear opportunities for industries.
The compactness and reduced energy requirements of the XLS facility have also important environment benefits, in particular a reduction of climate gas emission. Also, 51 young researchers have been involved in the project, with important benefits for educational and training.
The project will deliver to the scientific community a conceptual design of a machine with unique performance parameters and beam characteristics. The report will also include cost analyses and other strategic documents that support the decision-making process for constructing new facilities, or upgrading existing ones, using CompactLight technologies. The project will furthermore consider the complementary use of the technology for small infrastructures, that can be installed and operated at universities. Project data not affecting the potential exploitation of results by the partners will be made accessible as Open Data to facilitate the use of the technologies.
The major goal of CompactLight is to make the construction and operation of X-ray FELs feasible for smaller countries, regions and universities. This will support their wide-spread availability, reducing oversubscription of existing machines, and creating more and unique research opportunities for the scientific users. Given the large importance of FELs their wide dissemination will have an enormous impact on many different research fields, create access opportunities in more countries, and contribute significantly to European scientific and industrial competitiveness. An important aspect is also the coordinated flow of expertise from Europe’s larger research institutions to the smaller ones with ambitions to engage in cutting-edge photon science.
Major technology areas benefitting from the project are (a) high brightness e-sources (b) rf production and beam acceleration, (c) high-precision diagnostics, (d) undulators and photon production, etc., each of them with large application potential that goes beyond CompactLight and with clear opportunities for industries.
The compactness and reduced energy requirements of the XLS facility have also important environment benefits, in particular a reduction of climate gas emission. Also, 51 young researchers have been involved in the project, with important benefits for educational and training.