Outgassing and desorption of the stainless-steel beam tubes after different degassing treatments

Journal Article · Mon May 01 00:00:00 EDT 1989 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.575911· OSTI ID:6178503

Hseuh, H C; Cui, X

Chemical cleaning, vacuum firing, glow discharge cleaning, and in situ bakeout have become standard practice for lowering the outgassing rate and removing surface contaminants in the ultrahigh vacuum systems of particle accelerators and storage rings. This paper presents the work done with the thermal outgassing of several long stainless-steel (304LN and 316L) beam chambers with areas of more than 1 x 10/sup 4/ cm/sup 2/ . They were measured between 20 and 500 /sup 0/C after vacuum firing, glow discharge cleaning, or reactive gas (nitric oxide) cleaning. Outgassing rates of low 10/sup -13/ and low 10/sup -14/ Torr 1/s cm/sup 2/ were achieved for H/sub 2/ and CO, respectively, with vacuum firing alone. The outgassing of H/sub 2/ in this temperature range is consistent with that due to bulk diffusion with an enthalpy of 9 +- 1 kcal/mole. The photon stimulated desorption of the chamber surface after the above treatments were also studied by exposure to an intense photon beam at the National Synchrotron Light Source. The effectiveness and merits of reactive gas cleaning in removing the surface contaminants in large vacuum systems are compared to those of vacuum firing and glow discharge cleaning.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• OSTI ID: 6178503
• Journal Information: J. Vac. Sci. Technol., A; (United States), Vol. 7:3
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
VACUUM SYSTEMS
CAVITY RESONATORS
SURFACE PROPERTIES
DEGASSING
DESORPTION
EXPERIMENTAL DATA
HIGH TEMPERATURE
MEDIUM TEMPERATURE
STAINLESS STEEL-304L
STAINLESS STEEL-316L
SURFACE CLEANING
ULTRAHIGH VACUUM
ALLOYS
AUSTENITIC STEELS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CHROMIUM-NICKEL-MOLYBDENUM STEELS
CLEANING
CORROSION RESISTANT ALLOYS
DATA
ELECTRONIC EQUIPMENT
EQUIPMENT
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
LOW CARBON-HIGH ALLOY STEELS
MATERIALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NUMERICAL DATA
RESONATORS
STAINLESS STEELS
STEEL-CR17NI12MO3-L
STEEL-CR19NI10-L
STEELS
SURFACE FINISHING
430100* - Particle Accelerators- Design
Development
& Operation