Lessons Learned from the Jefferson Lab — SNS Cryomodule Production Run

Abstract

In light of the recent developments with the International Linear Collider (ILC), and the recommendation to utilize "Cold" technology for this future particle accelerator, this paper will present the lessons learned from the recently concluded Spallation Neutron Source (SNS) superconducting radio frequency (SRF) cryomodule production run at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). Over the past twenty years Jefferson Lab has worked with industry to successfully design, manufacture, test and commission more SRF cryomodules than any other entity in the United States. The knowledge gained from the design and fabrication of the SNS prototype, eleven -0.61 (medium) beta and the twelve -0.81 (high) beta cryomodules, will prove to be an effective asset to the ILC project. After delivery of the final production cryomodule in March 2005, design and fabrication data will be collected, evaluated and presented to make this information beneficial for future particle accelerator projects. Recommendations with respect to these findings will also be presented as an integral part of this paper.

Superfluid Helium Testing of a Stainless Steel to Titanium Piping Transition Joint

“…The use of active cooling had been important to the success of other bimetallic transition usage in cryomodules. [2]…”

“…The use of active cooling had been important to the success of other bimetallic transition usage in cryomodules. [2] Post-fabrication Ambient Leak Checks: Effect of Ultrasonic Cleaning Since the Transition Joint Test Assembly will be installed for testing on a vacuum system that normally is used for SRF cavity beam tubes, they must be particulate free. They received ultrasonic water cleaning.…”

“…Since SS and Ti cannot be joined by conventional electron-beam methods, alternative methods are under investigation and in use [1]. This has been successfully done for other SRF accelerator components [2]. A joint program involving JINR (Dubna, Russia), FNAL (Batavia, United States), INFN (Pisa, Italy), and IEP (Sarov, Russia) was conducted for further study [3].…”

Pursuing the Origin and Remediation of Low Q0 observed in the Original CEBAF Cryomodules

“…This, together with the existing cryomoudles, provides 1.1 GeV acceleration per linac. The performance specification for new cavities is 19.2 MV/m acceleration gradient with at 7.2×10 9 Q 0 at 2 K [7]. A second cryo plant is added, doubling the 2 K cooling power to ~ 10 kW (corresponding to a liquefier operating power of ~ 10 MW).…”