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Title: Results from sudden loss of vacuum on scaled superconducting radio frequency cryomodule experiment

Superconducting radio frequency (SRF) cavities for particle accelerators are at risk of failure due to sudden loss of vacuum (SLV) adjacent to liquid helium (LHe) spaces. To better understand this failure mode and its associated risks an experiment is designed to test the longitudinal effects of SLV within the beam tube of a scaled SRF cryomodule that has considerable length relative to beam tube cross section. The scaled cryomodule consists of six individual SRF cavities each roughly 350 mm long, initially cooled to 2 K by a superfluid helium bath and a beam tube pumped to vacuum. A fast-acting solenoid valve is used to simulate SLV on the beam tube, from which point it takes over 3 s for the beam tube pressure to equalize with atmosphere, and 30 s for the helium space to reach the relief pressure of 4 bara. A SLV longitudinal effect in the beam tube is evident in both pressure and temperature data, but interestingly the temperatures responds more quickly to SLV than do the pressures. It takes 500 ms (roughly 100 ms per cavity) for the far end of the 2 m long beam tube to respond to a pressure increase compared to 300more » ms for temperature (approximately 50 ms per cavity). The paper expands upon these and other results to better understand the longitudinal effect for SRF cryomodules due to SLV.« less
Authors:
;  [1] ; ;  [2]
  1. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
  2. National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States)
Publication Date:
OSTI Identifier:
22262766
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1573; Journal Issue: 1; Conference: Cryogenic engineering conference, Anchorage, AK (United States), 17-21 Jun 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 43 PARTICLE ACCELERATORS; ACCELERATORS; BEAMS; COMPARATIVE EVALUATIONS; DESIGN; FAILURES; HELIUM; PUMPS; SOLENOIDS; SUPERFLUIDITY; TUBES