BNL, Upton, Long Island, New York, USA
Niowave, Inc., Lansing, Michigan, USA
JLab, Newport News, Virginia, USA
ODU, Norfolk, Virginia, USA
LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
The final steps in the manufacturing of a superconducting RF cavity involve careful tuning before the final welds to match the target frequency as fabrication tolerances may introduce some frequency deviations. The target frequency is chosen based on analysis of the shifts induced by remaining processing steps including acid etching and cool down. The baseline fabrication of a DQW crab cavity for the High Luminosity LHC (HL-LHC) envisages a first tuning before the cavity subassemblies are welded together. To produce a very accurate final result, subassemblies are trimmed to frequency in the last machining steps, using a clamped cavity assembly for RF measurements. This paper will describe the trim tuning of one of the SPS prototype DQW crab cavities fabricated by Niowave.
CERN, Geneva, Switzerland
BNL, Upton, Long Island, New York, USA
As a part of the HL-LHC upgrade, a cryomodule is designed to host two crab cavities for a first test with protons in the SPS machine. The evaluation of the cryomodule heat loads is essential to dimension the cryogenic infrastructure of the system. The current design features two cryogenic circuits. The first circuit adopts superfluid helium at 2 K to maintain the cavities in the superconducting state. The second circuit, based on helium gas at a temperature between 50 K and 70 K, is connected to the thermal screen, also serving as heat intercept for all the interfaces between the cold mass and the external environment. An overview of the heat loads to both circuits, and the combined numerical and analytical estimations, is presented. The heat load of each element is detailed for the static and dynamic scenarios, with considerations on the design choices for the thermal optimization of the most critical components.
#Federico.carra@cern.ch
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
CERN, Geneva, Switzerland
KEKB was the first facility to implement the crab crossing technique in 2007, for the interaction of electron and positron beams. The High Luminosity Large Hadron Collider (HL-LHC) project envisages the use of crab cavities for increasing and levelling the luminosity of proton-proton collisions in LHC. Crab cavities have also been proposed and studied for future colliders like CLIC, ILC and eRHIC. This contribution will focus on the near and far future of crab cavities for particle colliders.
