Photon stimulated desorption measurements of extruded copper and of welded copper beam chambers for the PEP-II asymmetric B factory

Journal Article · Mon May 01 04:00:00 EDT 1995 · Journal of Vacuum Science and Technology, A

DOI:https://doi.org/10.1116/1.579789· OSTI ID:57102

Foerster, C L; Lanni, C ^[1]; Perkins, C ^[2]; Calderon, M; Barletta, W ^[3]

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1. National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. Stanford Linear Accelerator Center, Stanford, California 94305 (United States)
3. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

PEP II is being built as a higher luminosity electron--positron collider with asymmetric beams of 9 and 3.1 GeV, having maximum currents of 3.0 A. Based on our previous work on the National Synchrotron Light Source (NSLS) vacuum ultraviolet beamline U10B, a copper was selected for construction of ultrahigh vacuum beam chambers and absorbers to minimize the pressure rise from synchrotron radiation during operation. An extruded beam chamber and a welded beam chamber were fabricated from the selected copper for photon stimulated desorption measurements on the NSLS x-ray beamline X28A. The chambers were exposed to white light with a critical energy of 5 keV, both directly and through a 0.010-in.-thick beryllium filter. Each chamber was exposed to a dose of approximately 10{sup 23} photons per meter at an incidence angle of 25 mrad, after argon glow preconditioning and a 150 {degree}C vacuum bake. Desorption yields for H{sub 2} CO, CO{sub 2}, and CH{sub 4} are reported as a function of accumulated photon flux, critical energy, and chamber preparation. The results are compared with the previous work on the beamline U10B and with those of other published work on copper. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 57102
• Journal Information: Journal of Vacuum Science and Technology, A, Journal Name: Journal of Vacuum Science and Technology, A Journal Issue: 3 Vol. 13; ISSN JVTAD6; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
CARBON OXIDES
COPPER
EXTRUSION
HYDROGEN
METHANE
PEP STORAGE RINGS
PHYSICAL RADIATION EFFECTS
SORPTIVE PROPERTIES
SYNCHROTRON RADIATION
VACUUM SYSTEMS
WELDING