FEL/Duke University, Durham, North Carolina
SLAC, Menlo Park, California
Funding: *Work supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086 (YKWu).
Touschek scattering is the dominant loss mechanism for the electron beam in a low energy storage ring with a large bunch current. The Duke Free-Electron Laser (FEL) storage ring typically operates in the one-bunch or two-bunch mode with a very high bunch current and a varying electron beam energy as low as 250 MeV. The study of the Touschek lifetime is important for improving the performance of the Duke storage ring based light sources, including the storage ring FELs and a FEL driven Compton gamma source, the High Intensity Gamma-ray Source. This work reports our lifetime measurement results for few-bunch operation of the Duke storage ring. The Touschek loss rate is reduced when an electron beam is polarized in the storage ring. The change of the Touschek lifetime can be used as a method to monitor polarization of the electron beam. In this work, we will also report our preliminary results of the electron beam energy measurements using the resonant depolarization technique.
IHEP Beijing, Beijing
The 1.6GeV proton synchrotron proposed in the CSNS Project is a 25Hz rapid-cycling synchrotron (RCS) with 80MeV Linac. Beam power is aimed to 100kW at 1.6GeV. In this paper the designs of the prototype of DTL-Q power supply and the prototype of the resonant network with one mesh exciting in series will be introduced.
IHEP Beijing, Beijing
CSNS accelerator mainly consists of an H- linac and a proton rapid cycling synchrotron. It is designed to accelerate proton beam pulses to 1.6 GeV kinetic energy at 25 Hz repetition rate, striking a solid metal target to produce spallation neutrons. The accelerator is designed to deliver a beam power of 120 kW with the upgrade capability up to 500 kW, The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges in some key technologies. A series of R&D for major prototypes have being conducted since 2006, including an H- ion source, DTL tank, RF power supply for the linac, injection/extraction magnets and its pulse power supplies, dipole and quadrupole prototype magnets in the ring and its power supplies, ferrite-loaded RF prototype cavity, ceramic vacuum chamber, control and some beam diagnostics. This paper will briefly introduce the design and R&D status of the CSNS accelerator.
USTC/NSRL, Hefei, Anhui
Radial alternating magnetic field is generated to act on polarized beam to give rise to resonant depolarization and calibrate the energy of electron by feeding power to a pair of vertical installed striplines in HLS. In the paper, the relationship between depolarization time and power fed into the striplines is investigated, and spin frequency spread is considered too. As a result, a depolarization time of 60s is acquired with an amplifier power of 15W fed into the striplines.