AVS 46th International Symposium
    Vacuum Technology Division Tuesday Sessions
       Session VT-TuP

Paper VT-TuP4
The Measurement of Multi-Layer Insulation (MLI) Outgassing and its Impact on Effective Cryostat Pumping

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: R.J. Todd, Brookhaven National Laboratory
Authors: R.J. Todd, Brookhaven National Laboratory
D. Weiss, Brookhaven National Laboratory
D.J. Pate, Brookhaven National Laboratory
R. Davis, Brookhaven National Laboratory
Correspondent: Click to Email
The Relativistic Heavy Ion Collider (RHIC) is a superconducting particle collider that operates at cryogenic temperatures. The magnets used to bend and focus the beam are housed in twelve, 480 meter long, common cryostats. Outgassing rates of the MLI (multi-layer insulation) used in the cryostats were measured. Both the double aluminized mylar and polyester spacer material were tested for outgassing spectra and total quantity outgassed. To achieve a satisfactory base pressure in the cryostat, pumpdown estimates were made using the outgassing data. The number and size of pumps were varied to compare the effect on base pressure and water vapor loading of the pumps. Actual pumpdown curves were measured and compared with estimates. The effects of water vapor loading were also studied.