Overview of SNS Cryomodule Performance

Abstract

Thomas Jefferson National Accelerating Facility (Jefferson Lab) has completed production of 24 Superconducting Radio Frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) superconducting linac. This includes one medium-β (0.61) prototype, eleven medium-β and twelve high-β (0.81) production cryomodules. Nine medium-β cryomodules as well as two high-β cryomodules have undergone complete operational performance testing in the Cryomodule Test Facility at Jefferson Lab. The set of tests includes measurements of maximum gradient, unloaded Q (Q 0 ), microphonics, and response to Lorentz forces. The Q ext 's of the various couplers are measured and the behavior of the higher order mode couplers is examined. The mechanical and piezo tuners are also characterized. The results of these performance tests will be discussed in this paper.

RF Conditioning and Testing of Fundamental Power Couplers for SNS Superconducting Cavity Production

“…We have demonstrated at JLAB and Oak Ridge that the SNS fundamental power couplers can sustain, on the room temperature test stand, RF power levels in excess of machine specifications. To date, almost all couplers assembled on cavities have been successfully RF powered on the SNS cryomodules at JLAB and SNS [8] [9] and similar results are expected with beam operation in the near future.…”

Performance Overview of the Production Superconducting RF Cavities for the Spallation Neutron Source Linac

“…As part of the SNS SC Linac effort, 8 medium-β and 2 high-β cryomodules were tested in the JLab Cryomodule Test Facility (CMTF) [2]. This testing included measuring Q 0 vs E curves and onset of field emission, and provides an opportunity to compare cryomodule performance with cavity performance as measured in the VTA.…”