Distribution of Heating from Untrapped HOM Radiation in the LCLS-II Cryomodules

Journal Article · Thu Jan 01 00:00:00 EST 2015 · Physics Procedia

DOI:https://doi.org/10.1016/j.phpro.2015.11.057· OSTI ID:1236560

Bane, Karl ^[1]; Nantista, Christopher ^[1]; Adolphsen, Chris ^[1]; Raubenheimer, Tor ^[1]; Saini, Arun ^[2]; Solyak, Nikolay ^[2]; Yakovlev, Vyacheslav ^[2]

---

1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

The superconducting cavities in the CW linacs of LCLS-II will operate at 2 K, where cooling is very expensive. One source of heat is presented by the higher order mode (HOM) power deposited by the beam. Due to the very short bunch length, especially in the L3 region, the LCLS-II beam spectrum extends into the terahertz range. Ceramic absorbers, at 70 K between cryomodules, are meant to absorb much of this power. In this report we perform two kinds of calculations to estimate the effectiveness of the absorbers and the fractional power that remains to be removed at 2 K.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC03-76SF00515
• OSTI ID: 1236560
• Journal Information: Physics Procedia, Vol. 79, Issue C; ISSN 1875-3892
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
superconducting cavities
cryogenic heat load
impedance
wakefields
higher order modes