No seminar scheduled

R&D of CW Normal Conductivity VHF Gun at Tsinghua University (SHINE Injector)

• Yingchao Du (Tsinghua University)

A 217 MHz very-high-frequency gun operating in CW mode is being developed at Tsinghua University, which will be served as the beam source of the high repetition XFEL facilities and high repetition MeV UED. The cavity profile has been optimized to minimize input power, peak surface electric field, and peak wall power density. The profile optimization also takes into account the suppression of multipacting effect. Additionally, thermal analysis has been performed to guide the design of water cooling channels in coordination with gun mechanical design. The fabrication of the gun has been completed, and the frequency and quality factor measured in cold test are in good agreement with simulation expectations. During high power conditioning, 75 kW cw radio frequency power was successfully fed into the gun, corresponding to a cathode gradient of 27  MV/m and a gun voltage of 780 keV. Under this condition, the maximum dark current collected by the Faraday cup at the gun exit was 376 nA when the strength of the gun solenoid was scanned. To measure and optimize the beam quality, a test beamline was constructed. After preliminary optimization, the 95% projected transverse emittance was 0.161 mm mrad for 10 pC bunches with a bunch length of 0.49 mm rms, 0.429 mm mrad for 50 pC bunches with a bunch length of 1.15 mm rms, and 0.853 mm mrad for 100 pC bunches with a bunch length of 1.44 mm rms. Now one of the guns has been delivered to Shanghai and installed in the SHINE tunnel. Recently, it was operated in CW mode with ~75 kW input power and generated the first beam successfully.

A Hybrid, Asymmetric, Linear Higgs Factory based on Plasma Acceleration – the HALHF Concept

• Richard D'Arcy (University of Oxford)

Plasma-wakefield acceleration promises orders of magnitude higher gradients than can be achieved via conventional radio-frequency cavities. It is now starting to be used in real user facilities. However, its application to particle-physics colliders has always been complicated by the difficulty in accelerating positrons. I will introduce the basics of plasma wakefield acceleration and explain the difficulty with accelerating positrons. HALHF avoids this by using a conventional linac to accelerate positrons, resulting in an asymmetric-energy, hybrid linear facility which is much smaller, greener and cheaper than any conventional alternative Higgs-factory proposal. I will outline the HALHF layout and principles, possible upgrades to the Higgs factory and the R&D path to making it a reality.

Gamma Factory -- A Tool-driven Revolution?

• Mieczyslaw Witold Krasny (LPNHE, Sorbonne University, Paris, Centre National de la Recherche Scientifique (FR) and CERN)

High energy-frontier accelerators have provided the necessary research tools to establish the Standard Model by precision investigation of the strong and, subsequently, electro weak interactions at their characteristic energy scales of O(10-1000) MeV and O(100) GeV. What should be our next steps? Should we remain on the inertial progress-path and devote most of our resources to investigate the O(100) TeV scale with new high-energy frontier collider(s) -- even if we do not have any hint for new interactions at this energy scale, and the cost of the new high energy frontier colliders becomes large? Shouldn’t we investigate, in parallel, complementary development paths focused on studies of the emergent phenomena by developing new, unprecedented intensity and quality particle beams in the anthropomorphic energy domain? In this talk, I shall discuss two attempts going in such a direction. I shall concentrate mainly on the Gamma Factory project, being developed at CERN over the last 7 years. Its goal is to significantly broaden the present CERN research programme by including new components based on the novel-type light source. The proposed, partially-stripped-ion beam-driven light source is the backbone of the Gamma Factory project. It could be realized at CERN by re-using the infrastructure of the already existing accelerators and by profiting from the recent progress in laser technology. It could extend the scientific life of the LHC storage rings beyond its HL-LHC phase. The Gamma Factory could push the intensity limits of the presently operating light-sources by at least 7 orders of magnitude, reaching the flux of up to 10^18 photons/s, in the particularly interesting gamma-ray energy domain of 0.1 — 400 MeV, which is presently not accessible to the FEL photon sources. The partially stripped ion beams, the unprecedented-intensity energy-tuned gamma beams, together with the gamma-beam-driven secondary beams of polarized positrons, polarized muons, neutrinos, neutrons, and radioactive ions constitute the basic research tools of the Gamma Factory. A broad spectrum of new research opportunities, in a vast domain of uncharted fundamental and applied physics territories, could be opened by the Gamma Factory. Examples of new research opportunities and the status of the project development will be presented in this talk.

Physics at the CERN Secondary Beamlines

• Nikolaos Charitonidis (CERN)

The talk will provide a description of the secondary beamlines at CERN. More specifically, it will address the operational principles and the available beam parameters, as well as highlights of the exciting physics that takes place at these unique facilities at CERN. The talk will also cover HiRadMat - the high-energy, single-pulse facility for material tests at CERN.

Future Particle Physics Colliders with Sustainable Accelerating Systems

• Jorgen D'Hondt (Vrije Universiteit Brussel (BE))

In order to meet the ambitions of exploring the fundamentals of particle physics, the 2020 update of the European Strategy for Particle Physics emphasised the importance of an intensified and well-coordinated programme of accelerator R&D, supporting the design and delivery of future particle accelerators in a timely, affordable and sustainable way. Accelerating particles will always require a large amount of energy, hence achieving a minimal energy consumption is an unavoidable challenge and duty for future colliders. For many frontier accelerators, superconducting RF (SCRF) systems are the enabling technology. With the ambition to maintain competitiveness of European accelerator-based research infrastructures and to enable Europe’s Green Deal, a project has been proposed to Innovate for Sustainable Accelerating Systems (iSAS, https://indico.ijclab.in2p3.fr/event/9521/) with the aim to broaden, expedite and amplify the development and impact of novel energy-saving technologies to accelerate particles with enhanced collaborations. Directly connected to the SCRF accelerating system itself, three key technology areas requiring high power can provide significant energy-savings: RF power, cryogenics and beam energy recovery. The objective of iSAS is to develop, prototype and validate new impactful energy-saving technologies so that SCRF accelerators can provide the same, or improved, performance while using significantly less energy. Integrating iSAS technologies intrinsically in the design of especially high-energy and high-luminosity lepton accelerators is a prominent avenue to unlock a portfolio of impactful applications in particle physics with future electron-proton and electron-positron colliders.

Beam Irradiation Facilities

• Abbas NASREDDINE (ARIEL)

During this seminar, a presentation of the Technological Resources Center “Aerial” will be given, showing the multiple research platforms, covering multiple scientific fields (radiation, microbiology, physical chemistry, freeze drying and sensory evaluation). A focus on Aerial’s Excellence Center for Radiation Processing will be given. These multiple irradiation facilities available at Aerial (low, medium and high energy electron and X-ray beams) are open to research projects and collaborations. On the other hand, an overview of common and novel radiation applications will be given.

No seminar scheduled