Abstract: Precise neutrino cross section measurements and search for sterile neutrinos can be done with neutrino beams produced from muons decaying in a storage ring due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a racetrack storage ring, where circulating muon beam would be captured. The storage ring has three options: a FODO solution with large aperture quadrupoles, a racetrack FFA (Fixed Field alternating gradient Accelerator) using the recent developments in FFAs and a hybrid solution of the two previous options. Machine parameters, linear optics design and beam dynamics of the different solutions are discussed in this talk.
Abstract: The “Laser-hybrid Accelerator for Radiobiological Applications,” LhARA, is proposed as a novel, flexible facility dedicated to the study of radiobiology. LhARA will be a hybrid accelerator system in which laser interactions drive the creation of a large flux of protons or light ions that are captured using a plasma (Gabor) lens and formed into a beam. It is proposed that LhARA be developed in two stages. In the first stage, a programme of in vitro radiobiology will be served with proton beams with energies between 10 and 15 MeV. In stage two, the beam will be accelerated using a fixed-field alternating-gradient accelerator (FFA). This will allow experiments to be carried out in vitro and in vivo with proton beam energies of up to 127 MeV. In addition, ion beams with energies up to 33.4 MeV per nucleon will be available for in vitro and in vivo experiments. The technologies demonstrated in LhARA, which have wide application, will be developed to allow particle-beam therapy to be delivered in a new regimen, combining a variety of ion species in a single treatment fraction and exploiting ultra-high dose rates, including the “FLASH” regime. This talk presents briefly the design of the entire facility and focuses on the studies of the FFA ring post-accelerator.
Abstract: Muon to electron conversion in a muonic atom is an excellent laboratory to search for charged lepton flavor violation (CLFV). Its discovery would be a clear sign of physics beyond the Standard Model. In order to further improve the sensitivity of current experiments (COMET and Mu2e) by an additional factor of 100 and study potential signals, it was proposed to use a Phase Rotated Intense Source of Muons (PRISM). In PRISM system short, high intensity proton bunches are sent to a production target followed by a high acceptance capture/transport system, where the muon beam will be formed and subsequently injected into the FFA ring, which will allow significant purification of the muon beam and suppression of a typically large momentum spread by the use of RF phase rotation, both reducing the backgrounds and increasing the efficiency of muon stopping target. PRISM requires a proton driver capable of producing short, intense proton bunches. Development of new facilities, in particular PIP-II at Fermilab equipped with a dedicated accumulator ring, or upgrades of other accelerator facilities, such as J-PARC and ESS, offer promising opportunities for providing the required intensity and time structure of the proton beam for PRISM. This talk presents the current status and prospects for the PRISM R&D work in a near future.
Invited Speaker: Ming Li (on behalf of Tianjue Zhang)
Abstract: Proton beam with an average power of 5MW-10MW have important applications in particle physics towards the intensity frontier, as well as in the advanced energy, and material science. In 2019, a 2GeV/6MW CW FFA was proposed in China Institute of Atomic Energy (CIAE), which adopts a 100 MeV and 800 MeV Ring cyclotron for injection. From the perspective of the accelerator physics, the 2GeV FFA solution with 10 cells meets most of the requirements, except that the Vr=3 resonance are crossed. The technical requirements for the RF system are far from critical which is feasible in engineering. While the tolerance of the first harmonic, less than 1 Gs due to the resonance crossing, is too harsh for the magnet engineering. In 2020, the progress for the optimization design and construction of the 2GeV FFAG includes: 1) Physical design optimization. Making compromise between various physical design parameters and engineering parameters, solutions with different cell numbers and overall size are compared to determine the optimized physical design scheme, which is expected to be feasible in the engineering of the major systems, such as the magnet and RF system. 2) Pre-research of the high temperature superconducting (HTS) magnets. The physical, engineering design of the test-magnet and the HTS coils winding test have been completed. Through the confirmed technical route, the fabrication of the HTS coils has started and is planned to be finished in January 2021. In addition, the engineering design of the radial-varying-gradient formal magnet has also been completed and fabrication will begin soon. 3) RF system design and manufacturing. After the physical and engineering design of the RF system has been completed, we start the machining of the scale-down high frequency cavity with high Q-Value and large radial width, which is expected to be completed in February 2021. This report will outlined the status of the FFA design and the detail of the recent progress.
