Radiation cleanup of vacuum systems (radiation-induced outgassing). Final report, September 15, 1976--November 14, 1977
A stainless steel-304 vacuum system has been designed and constructed to study radiation-induced outgassing when this material is exposed to cobalt-60 gamma radiation. The system is pumped with an ion pump and sorption roughing pump. No foreign materials have been introduced except for copper seals at the flanges. An analytical model has been developed which predicts the outgassing from SS-304 to be 8.27 x 10/sup -12/ torr-liters/(cm/sup 2/) (sec) per megarad/hr. Extrapolation of existing data for aluminum suggests a lower value of 1.0 x 10/sup -12/ torr-liters/(cm/sup 2/) (sec) per megarad/hr. Experiments determined the value for stainless steel-304 after bakeout at 300 C to be (7.78 +- 4.36) x 10/sup -12/ torr-liters/(cm/sup 2/) (sec) per megarad/hr, in good agreement with the analytical model predictions. Studies on thermally-induced outgassing from SS-304 showed that after bakeout at temperature T*, thermal outgassing ..delta.. obeys the relationship ..delta.. = ..delta../sub 0/e/sup -antiQ/RT/, where both the constant ..delta../sub 0/ and the average desorption energy antiQ are functions of T*. Water vapor and hydrogen are the principal residual gases in a 304 SS vacuum system, with hydrogen being dominant at low pressures after bakeout.
- Research Organization:
- Cincinnati Univ., Ohio (USA)
- DOE Contract Number:
- EY-76-S-02-4093
- OSTI ID:
- 7179052
- Report Number(s):
- COO-4093-2; TRN: 78-011472
- Country of Publication:
- United States
- Language:
- English
Similar Records
Outgassing rate of the copper-plated beam tube for ISABELLE
Radiation-induced outgassing from Type 304 stainless steel
Related Subjects
STAINLESS STEEL-304
CLEANING
THERMONUCLEAR REACTORS
VACUUM SYSTEMS
DEGASSING
GAMMA RADIATION
MATHEMATICAL MODELS
VACUUM PUMPS
ALLOYS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
ELECTROMAGNETIC RADIATION
HEAT RESISTING ALLOYS
IONIZING RADIATIONS
IRON ALLOYS
IRON BASE ALLOYS
LABORATORY EQUIPMENT
NICKEL ALLOYS
PUMPS
RADIATIONS
STAINLESS STEELS
STEELS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing