AVS 60th International Symposium and Exhibition
    Vacuum Technology Wednesday Sessions
       Session VT-WeM

Paper VT-WeM12
Higher Order Mode RF Absorbers for Cornell ERL Superconducting Cavity Cryo-Module

Wednesday, October 30, 2013, 11:40 am, Room 202 C

Session: Pumps, Accelerators and Large Vacuum Systems
Presenter: Y. Li, Cornell University
Authors: Y. Li, Cornell University
Y. He, Cornell University
J.V. Conway, Cornell University
R.G. Eichhorn, Cornell University
Correspondent: Click to Email
As a part of continuing R&D efforts toward to Cornell Energy Recover LINAC based hard X-ray light sources, a superconducting RF (SRF) cavity cryo-module (the so-called horizontal test cryo-module or HTC) has been designed and constructed, and a series of tests has been carried out during the past year to evaluate performance of the SRF cavities. One of the key and challenging components, which are still in development, is the higher order mode (HOM) RF absorber. The UHV compatibility is essential for these HOM RF absorbers, as they form part of electron accelerator beampipes adjacent to the SRF cavities. The out-gassing rates of various HOM RF absorber materials were measured by a throughput method. In the presentation, we report vacuum out-gassing measurements on various candidate HOM absorber materials, including two promising materials, namely SiC and AlN. We will also discuss several joint designs (such as vacuum brazing and shrink-fit) for the absorbers to ensure that the assembly is not only UHV compatible, but also works properly from bakeout temperature (150C) to cryogenic temperature (80K).