Periodic Reporting for period 3 - EuPRAXIA (Proposal for a Horizon 2020 Design Study on the “European Plasma Research Accelerator with eXcellence In Applications“ (EuPRAXIA)) Reporting period: 2018-11-01 to 2019-10-31 Summary of the context and overall objectives of the project EuPRAXIA is a design study on a “European plasma research accelerator with excellence in applications”. It aims at developing innovative plasma technology for compact and cost-efficient electron accelerators, enabling ground-breaking applications in photon science, high-energy physics, health and industry. The European research infrastructure EuPRAXIA would host compact plasma accelerators, modern lasers from European industry, and pilot user areas.Over the last century, particle accelerators have become powerful and widely used tools for industry, medicine and science. Today there are more than 30,000 particle accelerators worldwide. All of them rely on highly developed technologies for increasing the energy of charged particles. However, the achievable particle energy is often limited by practical boundaries on size and cost, e.g. the available space in hospitals, the available funding in universities or the cost that society as a whole can afford for science projects at the energy frontier. A new type of accelerator that uses plasmas instead of the conventional radiofrequency (RF) cavities provides acceleration rates 1,000 times higher than those of conventional machines. This allows for much smaller accelerators with a wide range of applications. EuPRAXIA brings together a consortium of 16 laboratories and universities from 5 EU member states. 25 associated partners from 13 countries in Europe, Asia and North America have also joined with in-kind commitments. The scientists represent expertise from accelerator science and high-energy physics, leading accelerators like the LHC, advanced acceleration test facilities like SPARC, and frontier laser projects like CLF, CILEX and ELI.Based on this interdisciplinary collaboration and four years of hard work, the EuPRAXIA project has produced a conceptual design report for a new plasma-accelerator-based research facility. It describes innovative solutions that combine state-of-the-art accelerator technology, plasma expertise, modern lasers, industrial know-how and advanced feedback systems. The proposed design strategies improve the quality of plasma-accelerated electron beams, such that applications are enabled. Additionally, user areas have been developed for free-electron laser (FEL) studies, tabletop high-energy physics test beams, medical applications, industry tests and more. The design report also presents an implementation model as a distributed infrastructure with multiple sites and centres across Europe. Depending on funding, it is estimated that such a facility could be prepared and implemented within an 8-to-10-year timeframe. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far The EuPRAXIA study considered a multitude of concepts and schemes for power sources, particle injection and acceleration, beam transport, and applications based on the goal parameters identified at the beginning of the project. Experiments at various European facilities together with start-to-end simulations were carried out to narrow down this range and identify the five most promising technical scenarios. The research was centred on improving the beam quality of a 5 GeV electron plasma accelerator by using two complementary technology directions: in one case a high-power laser is employed to drive the acceleration process, in the other a high-energy electron beam is the driver. In all configurations, a significant improvement in beam quality was eventually predicted, up to a factor of 10 in some parameters and even approaching the single-pulse performance of conventional RF accelerators. The conceptual design process also provided key results in other aspects. A high-power laser system with unprecedented repetition rate was designed and paths developed to even higher average power for EuPRAXIA. Additionally, the conceptual machine design proposes a comparably compact accelerator footprint, about six times smaller than RF accelerators of equivalent beam energy - a significant step towards more compact, more affordable accelerator-based machines in the future. Finally, the EuPRAXIA consortium defined and developed several impactful applications for this proposed high-quality accelerator. Intense X-ray and gamma-ray pulses, for example, from an innovative plasma-based free-electron laser and other tabletop sources are foreseen. These will be useful for medical imaging, studying chemical and biological processes at ultrafast and ultrasmall scales and many other applications. In addition, extremely short electron and positron beams could be produced at the proposed EuPRAXIA facility. These can act as tools for high-energy physics testing as well as for deeply penetrating high-resolution material studies.A main deliverable of the EuPRAXIA study and key tool for disseminating its outcomes is the EuPRAXIA Conceptual Design Report that was completed in Oct 2019. Important results have also been presented at conferences and workshops over the past four years and published in scientific journal and magazine articles to reach a broad audience. While some of the concepts and schemes developed for EuPRAXIA can be directly applied in consortium partner institutions, a full exploitation of the design is planned via further work on EuPRAXIA and the eventual implementation of the final infrastructure. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Plasma accelerators have immense promise for the innovation of affordable and compact accelerators for various applications, from high-energy physics to medical and industrial uses. Once fully developed, the technology resulting from the EuPRAXIA project will facilitate the access to accelerators for new users and in new locations (e.g. universities, hospitals, and mobile platforms), and even replace some of the RF accelerators currently found in particle colliders and research facilities. This will multiply the application of accelerators and create major advances in knowledge and capabilities, some of them yet unimaginable.The broad and interdisciplinary EuPRAXIA collaboration will also create a critical mass of expertise and capabilities in Europe. It will defend and further position Europe as a clear world-wide leader in accelerator innovation. The EuPRAXIA project will challenge and support the European and world-wide laser industry to further develop their products on high-power pulsed lasers. This will boost the laser and other related industries overall but in particular enable European laser companies to stay world-leading in a fair and competitive effort.Finally, new generations of scientists and technicians in the EU will be exposed to innovative and highly challenging technical and intellectual problems in centrally located and well-integrated R&D facilities. The proximity to research institutes and universities in the EU will amplify the capability of EuPRAXIA to fascinate young generations for science and technology, to foster innovative “out-of-the-box” thinking, to serve as a high-tech training base and to strengthen the job base for technical work.First results of many of these activities can already be observed at the end of the design study. The cooperation within the plasma accelerator community has increased, e.g. through common EuPRAXIA experiments; connections with laser and other industries have been improved and will be sustained in the future through an early involvement of companies in the design process; and some of the new technical concepts developed for EuPRAXIA are already in planning to be implemented in project partner institutions. Map of EuPRAXIA partners and associated partners EuPRAXIA Logo Overview of topics and application fields relevant for EuPRAXIA Conceptual visualisation of a plasma accelerating section of the proposed EuPRAXIA machine Conceptual visualisation of the high-energy positron and test beam beamline of the EuPRAXIA machine
