BNL, Upton, New York, USA
ODU, Norfolk, Virginia, USA
SLAC, Menlo Park, California, USA
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
Crab cavity is essential for retrieving the loss in luminosity due to the large crossing angle in the two colliding beam lines of the Electron Ion Collider (EIC). Due to the asymmetric design of the proton beam crab cavity, the fundamental mode consists of contributions from higher order multipoles. These multipole modes may change during fabrication and installation of the cavities, and therefore affect the local dynamic aperture. Thresholds for each order of the multipoles are applied to ensure dynamic aperture requirements at these crab cavities. In this paper, we analyzed the strength of the multipoles due to fabrication and installation accuracies, and set limitations to each procedure to maintain the dynamic aperture requirement.
TUOZGD3
SLAC, Menlo Park, California, USA
UCSF, San Francisco, California, USA
Northwestern University, Northwester Medicine Proton Center, Warrenville, Illinois, USA
LLU, Loma Linda, USA
We report on the development of a 2.856 GHz accelerator system to provide energy modulation and RF-based steering for rapid 3-D beam scanning for proton therapy. Designs for the accelerator and deflector cavities have been modeled in ANSYS-HFSS and used to produce prototype structures. We present high power test results for a single cell energy modulator prototype and a three cell deflector prototype. Using General Particle Tracer, we simulate proton beam transport through the fully rendered accelerator and deflector beamline. System performance is optimized for the case of sub-relativistic protons with 230 MeV kinetic energy and covers an energy modulation range of ±30 MeV. We present simulated beam profile data after energy modulation and lateral steering, achieved using a combination of dynamic RF deflector cavities and static permanent magnet quadrupoles.
LANL, Los Alamos, New Mexico, USA
UNM-ECE, Albuquerque, USA
SLAC, Menlo Park, California, USA
A cold copper distributed coupling accelerator, with a high accelerating gradient at cryogenic temperatures (~77 K), is proposed as a baseline structure for the next generation of linear colliders. This novel technology improves accelerator performance and allows more degrees of freedom for optimization of individual cavities. It has been suggested that C-band accelerating structures at 5.712 GHz may allow to maintain high efficiency, achieve high accelerating gradient, and be suitable beam dynamics with wakefield damping and detuning of the cavities. The optimization of the cavity shape was performed and we computed quality factor, shunt impedance, and beam kick factor for each of the proposed cavity geometries using CST microwave studio. Next, we proposed a configuration for higher order mode (HOM) suppression that includes waveguide slots running parallel to the axis of the accelerator. This presentation will report details of the parametric study of performance of the HOM suppression waveguide, and the dependence of HOM Q-factors and kick-factors on the cavity’s and HOM waveguide’s geometries.