Paper | Title | Page |
---|---|---|
TUPAC14 | A Linear Envelope Model for Multi-Charge State Linac | 478 |
|
||
Funding: U.S. Department of Energy The traditional linear envelope tracking model is widely used in linac design and on-line tuning. However, for multi-charge state acceleration situation, where the transfer matrix is different between charge-states, the linear envelope tracking model cannot be utilized. A direct way to handle multi-charge state acceleration is using multi-particle tracking, which is usually high in precision, but lack in efficiency, therefore is not suitable for linac on-line beam tuning. In this paper, a new approach of adapting linear envelope tracking model onto multi-charge state acceleration situation is proposed. The lattice of FRIB is used to test the scheme in both linac segment and folding segment. And the result is then benchmarked with a multi-particle tracking program IMPACT to ensure its precision with enhancement in efficiency. |
||
WEPAC03 | Electro-Magnetic Optimization and Analysis of a Quarter Wave Resonator | 790 |
|
||
Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 A β=0.085 quarter wave resonator (QWR) with resonant frequency=80.5 MHz is used in the Facility of Rare Isotope Beam (FRIB). Its baseline structure is designed to achieve the FRIB specifications with optimum cost to performance ratio. Electro-magnetic optimization is introduced in this paper to modify its internal geometry to reach instead maximum accelerating gradient, while preserving the original flange to flange length. Reduced peak magnetic field and increased shunt impedance are well achieved in the optimization while keeping the same stored energy. The maximum accelerating voltage is raised accordingly. Multipacting and steering are also analyzed for the optimized cavity. This resonator could be used in the ReA linac at MSU and in all applications where the maximum accelerating voltage should be achieved in a limited space, or where the accelerator cost is mainly driven by the resonator gradient. |
||
THPHO01 | Parameter Optimization for Multi-Dimensional Laser Cooling for an Ion Beam in the Storage Ring S-LSR | 1298 |
|
||
Funding: Advanced Compact Accelerator Development project, MEXT, Japan. GCOE project, Kyoto University, Japan. Abstract: S-LSR is a compact ion cooler ring built in ICR, Kyoto University, aiming at creating ultra-low temperature ion beam by laser cooling. In order to approach lowest possible temperature at S-LSR in an experiment, parameters of laser cooling should be carefully chosen by simulation. This paper mainly concerns on optimization of laser cooling parameters and prediction of possible low limit of beam temperature at S-LSR. Firstly, the adiabatic capture process of ion beam is introduced and studied. Then, different laser profile parameters are compared and an optimized value is chosen. After that, optimized solenoid field strength for 3-D coupling is proposed. At last, by choosing the parameters proposed, the lowest beam temperature achievable for S-LSR is predicted to be 10K in horizontal direction and 0.05K in longitudinal direction. |
||
THPMA02 | Study of Microphonics Compensation for SRF Cavity | 1355 |
|
||
Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Microphonics and Lorentz Force detune the resonance frequency of a SRF cavity, leading to perturbations of the amplitude and phase of its accelerating field. Although this disturbance could be compensated by a piezo-electric tuner or with additional RF power, these two methods have conflicts, which is observed as unstable RF fields in a recent experiment. These conflicts could be explained by a model. Further experiments on ReA3 [1] cryomodule validates a conflict suggested by the model. Overall optimization of control algorithm is still needed to effectively combine the two methods. |
||
FRYBA1 | Progress towards the Facility for Rare Isotope Beams | 1453 |
|
||
Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Facility for Rare Isotope Beams (FRIB) is based on a continuous-wave superconducting heavy ion linac to accelerate all the stable isotopes to above 200 MeV/u with a beam power of up to 400 kW. At an average beam power approximately two-to-three orders-of-magnitude higher than those of operating heavy-ion facilities, FRIB stands at the power frontier of the accelerator family - the first time for heavy-ion accelerators. To realize this innovative performance, superconducting RF cavities are used starting at the very low energy of 500 keV/u, and beams with multiple charge states are accelerated simultaneously. Many technological challenges specific for this linac have been tackled by the FRIB team and collaborators. Furthermore, the distinct differences from the other types of linacs at the power front must be clearly understood to make the FRIB successful. This report summarizes the technical progress made in the past years to meet these challenges. |
||