WEYB1
Niowave, Inc., Lansing, Michigan, USA
BNL, Upton, Long Island, New York, USA
Niowave, Inc., Lansing, Michigan, USA
A 5-cell SRF cavity operating at 704 MHz will be used for Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the ability of relativistic electrons to cool a single bunch of heavy ions in RHIC. The cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up 22 MeV. Novel mechanical designs, including the super fluid heat exchanger, helium vessel, vacuum vessel, tuner mechanism, and FPC are presented. Structural and modal analysis, using ANSYS were performed to confirm the cavity chamber and He vessel structural stability and to calculate the tuning sensitivity of the cavity. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.
LANL, Los Alamos, New Mexico, USA
MIT/PSFC, Cambridge, Massachusetts, USA
Niowave, Inc., Lansing, Michigan, USA
We present an update on the 2.1 GHz superconducting rf (SRF) photonic band gap (PBG) resonator experiment in Los Alamos. The new SRF PBG cell was designed with the particular emphasis on changing the shape of PBG rods to reduce the peak magnetic fields and at the same time to preserve its effectiveness for suppression of the higher order modes (HOMs). The new PBG cells have great potential for outcoupling long-range wakefields in SRF accelerator structures without affecting the fundamental accelerating mode. Using PBG structures in superconducting particle accelerators will allow operation at higher frequencies and moving forward to significantly higher beam luminosities thus leading towards a completely new generation of colliders for high energy physics. Here we report the results of our efforts to fabricate 2.1 GHz PBG cells with elliptical rods and to test them with high power in a liquid helium bath at the temperature of 2 Kelvin. The high gradient performance of the cells will be evaluated and the results will be compared to electromagnetic and thermal simulations.
Stony Brook University, Stony Brook, USA
BNL, Upton, Long Island, New York, USA
Niowave, Inc., Lansing, Michigan, USA
SBU, Stony Brook, New York, USA
The 112 MHz quarter wave superconducting electron gun was designed and built as an injector for the coherent electron cooling experiment. Besides that, the gun is suitable for testing various types of photocathodes thanks to its specially designed cathode holder. In recent RF tests of the gun at 4 K, the accelerating voltage reached 0.9 MV CW and more than 1 MV in pulsed mode. During this testing, we observed several multipacting barriers at low electromagnetic field levels. Since the final setup of the gun will be different from the cool down test configuration, we want to understand the exact location of the multipacting sites. We used Track3P to simulate multipacting. The results show several resonant trajectories that might be responsible for the observed barriers, but fortunately no strong multipacting barriers have been found in the cavity.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Niowave, Inc., Lansing, Michigan, USA
Fermilab, Batavia, USA
SBU, Stony Brook, New York, USA
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
Efforts to experimentally prove a concept of the coherent electron cooling are underway at BNL. A short 22-MeV linac will provide high charge, low repetition rate beam to cool a single ion bunch in RHIC. The linac will consist of a 112 MHz SRF gun, two 500 MHz normal conducting bunching cavities and a 704 MHz five-cell accelerating SRF cavity. The paper describes the SRF and RF systems, the linac layout, and discusses the project status, first test results and schedule.