Mechanical stability study of capture cavity II at fermilab

Author

McGee, M.W. ; Pischalnikov, Y.

Author_Institution

Fermi Nat. Accel. Lab., Batavia

fYear

2007

fDate

25-29 June 2007

Firstpage

2274

Lastpage

2276

Abstract

Problematic resonant conditions at both 18 Hz and 180 Hz were encountered and identified early during the commissioning of Capture Cavity II (CC2) at Fermilab. CC2 consists of an external vacuum vessel and a superconducting high gradient (close to 25 MV/m) 9-cell 1.3 GHz niobium cavity, transported from DESY for use in the A0 Photoinjector at Fermilab. An ANSYS modal finite element analysis (FEA) was performed in order to isolate the source of the resonance and directed the effort towards stabilization. Using a fast piezoelectric tuner to excite (or shake) the cavity at different frequencies (from 5 Hz to 250 Hz) at a low-range sweep for analysis purposes. Both warm (300 K) and cold (1.8 K) accelerometer measurements at the cavity were taken as the resonant "fix" was applied. FEA results, cultural and technical noise investigation, and stabilization techniques are discussed.

Keywords

accelerometers; finite element analysis; piezoelectric devices; superconducting cavity resonators; vacuum apparatus; A0 photoinjector; ANSYS modal finite element analysis; Fermilab; accelerometer measurements; capture cavity II; frequency 1.3 GHz; niobium cavity; piezoelectric tuner; superconducting high gradient; vacuum vessel; Accelerometers; Cultural differences; Finite element methods; Frequency; Niobium; Performance analysis; Resonance; Stability; Superconducting device noise; Tuners;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2007. PAC. IEEE

Conference_Location

Albuquerque, NM

Print_ISBN

978-1-4244-0916-7

Type

conf

DOI

10.1109/PAC.2007.4441221

Filename

4441221