BNL, Upton, Long Island, New York, USA
CERN, Geneva, Switzerland
Stony Brook University, Stony Brook, USA
SLAC, Menlo Park, California, USA
LBNL, Berkeley, California, USA
The LHC high luminosity project envisages the use of the crabbing technique for increasing and levelling the LHC luminosity. Double-Quarter Wave (DQW) resonators are compact cavities especially designed to meet the technical and performance requirements for LHC beam crabbing. A couple of DQW crab cavities are under preparation and will be tested with beam in the Super Proton Synchrotron (SPS) of CERN by 2017. This paper describes the design and prototyping of DQW crab cavities for the SPS test.
Stony Brook University, Stony Brook, USA
BNL, Upton, Long Island, New York, USA
The first RF commissioning of 112 MHz QWR superconducting electron gun was done in late 2014. The coaxial Fundamental Power Coupler (FPC) and Cathode Stalk (stalk) were install and tested for the first time. During this experiment, we observed several multipacting barriers at varied gun voltage levels. The simulation work was done within the same range. The comparison between the experimental observation and the simulation results are presented in this paper. The observations during the test are consisted with the simulation predictions. We were able to overcome most of the multipacting barriers and reach 1.7 MV gun voltage under pulsed mode after several round of conditioning processes.
Stony Brook University, Stony Brook, USA
Transfer Engineering and Manufacturing, Inc, Fremont, California, USA
BNL, Upton, Long Island, New York, USA
Stangenes Industries, Palo Alto, California, USA
Two electron beams from two activated bulk GaAs photocathodes were successfully combined during the recent beam test of the High Current High Polarization Electron gun for eRHIC. The beam test took place at Stangenes Industries in Palo Alto, CA, where the cathodes were placed in radially opposite locations inside the high voltage shroud. No significant cross talking between the cathodes were found for the pertinent vacuum and low average current operation, which is very promising towards combining multiple beams for higher average current. This paper describes the cathode preparation, transport and cathode performance in the gun for the combining test, including the QE and lifetimes of the photocathodes at various steps of the experiment.
BNL, Upton, Long Island, New York, USA
Transfer Engineering and Manufacturing, Inc, Fremont, California, USA
Stangenes Industries, Palo Alto, California, USA
Stony Brook University, Stony Brook, USA
A prototype of a high average current polarized electron funneling gun as an eRHIC injector has been built at BNL. The gun was assembled and tested at Stangenes Incorporated. Two beams were generated from GaAs photocathodes and combined by a switched combiner field. We observed the combined beams on a YAG crystal and measured the photocurrent by a Faraday cup. The gun has been shipped to Stony Brook University and is being tested there. In this paper we will describe the major components of the gun and recent beam test results. High voltage conditioning is discussed as well.
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase I a 112 MHz superconducting RF photoemission gun and two 500 MHz normal conducting bunching cavities were installed and commissioned. The paper describes the Phase I linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems.
BNL, Upton, Long Island, New York, USA
ANL, Argonne, Illinois, USA
Niowave, Inc., Lansing, Michigan, USA
Fermilab, Batavia, Illinois, USA
A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system currently 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 to 22 MeV. Novel mechanical designs, including the helium vessel, vacuum vessel, tuner mechanism, and FPC are presented. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for the CeC PoP experiment.
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BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
Lancaster University, Lancaster, United Kingdom
CERN, Geneva, Switzerland
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A double quarter wave crab cavity (DQWCC) was designed for the Large Hadron Collider (LHC) luminosity upgrade. A compact Higher Order Mode (HOM) filter with wide stop band at the deflecting mode is developed for this cavity. Multi-physics finite element simulation results are presented. The integration of this design to the cavity cryomodule is described.
BNL, Upton, Long Island, New York, USA
CERN, Geneva, Switzerland
Stony Brook University, Stony Brook, USA
SLAC, Menlo Park, California, USA
A Proof-of-Principle (PoP) Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. A vertical cryogenic test has been done at Brookhaven National Lab (BNL). The cavity achieved 4.5 MV deflecting voltage with a quality factor above 3×109. We report the test results of this design.