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Title: Degassing a vacuum system with in-situ UV radiation

Abstract

Photon-stimulated desorption (PSD) from a high-powered ultraviolet source was investigated as a technique to degas a vacuum system. A stainless steel vacuum system was pumped down from atmosphere with different time doses of 185 nm light, and the resulting outgassing rates were compared to that of a control pumpdown without UV assistance. PSD was found to provide a factor of 2 advantage in pumpdown pressure after only 30 min of UV exposure, with no additional advantage observed for longer irradiation times. Specifically, an outgassing rate of 3 Multiplication-Sign 10{sup -10} Torr L s{sup -1} cm{sup -2} was reached 3 h sooner in pumpdowns with UV assistance compared to those without UV, while a rate of 1.2 Multiplication-Sign 10{sup -10} Torr L s{sup -1} cm{sup -2} was reached 16 h sooner in UV runs. The authors calculated that about 22 monolayers of water were desorbed after 30 min of UV exposure. The results indicate that PSD by a 40 W 185 nm UV source can serve as a nonthermal technique to significantly speed the pumpdown of a vacuum system from atmosphere after only 30 min.

Authors:
; ;  [1];  [2]
  1. College of William and Mary, Department of Applied Science, 325 McGlothlin Street Hall, Williamsburg, Virginia 23187 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22099104
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films
Additional Journal Information:
Journal Volume: 30; Journal Issue: 6; Other Information: (c) 2012 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0734-2101
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; DEGASSING; DESORPTION; IRRADIATION; PHOTONS; PUMPING; STAINLESS STEELS; ULTRAVIOLET RADIATION; VACUUM SYSTEMS; VISIBLE RADIATION; WATER

Citation Formats

Koebley, Sean R., Outlaw, Ronald A., Dellwo, Randy R., and RBD Instruments, 2437 Northeast Twin Knolls Drive, Bend, Oregon 97701. Degassing a vacuum system with in-situ UV radiation. United States: N. p., 2012. Web. doi:10.1116/1.4754292.
Koebley, Sean R., Outlaw, Ronald A., Dellwo, Randy R., & RBD Instruments, 2437 Northeast Twin Knolls Drive, Bend, Oregon 97701. Degassing a vacuum system with in-situ UV radiation. United States. doi:10.1116/1.4754292.
Koebley, Sean R., Outlaw, Ronald A., Dellwo, Randy R., and RBD Instruments, 2437 Northeast Twin Knolls Drive, Bend, Oregon 97701. Thu . "Degassing a vacuum system with in-situ UV radiation". United States. doi:10.1116/1.4754292.
@article{osti_22099104,
title = {Degassing a vacuum system with in-situ UV radiation},
author = {Koebley, Sean R. and Outlaw, Ronald A. and Dellwo, Randy R. and RBD Instruments, 2437 Northeast Twin Knolls Drive, Bend, Oregon 97701},
abstractNote = {Photon-stimulated desorption (PSD) from a high-powered ultraviolet source was investigated as a technique to degas a vacuum system. A stainless steel vacuum system was pumped down from atmosphere with different time doses of 185 nm light, and the resulting outgassing rates were compared to that of a control pumpdown without UV assistance. PSD was found to provide a factor of 2 advantage in pumpdown pressure after only 30 min of UV exposure, with no additional advantage observed for longer irradiation times. Specifically, an outgassing rate of 3 Multiplication-Sign 10{sup -10} Torr L s{sup -1} cm{sup -2} was reached 3 h sooner in pumpdowns with UV assistance compared to those without UV, while a rate of 1.2 Multiplication-Sign 10{sup -10} Torr L s{sup -1} cm{sup -2} was reached 16 h sooner in UV runs. The authors calculated that about 22 monolayers of water were desorbed after 30 min of UV exposure. The results indicate that PSD by a 40 W 185 nm UV source can serve as a nonthermal technique to significantly speed the pumpdown of a vacuum system from atmosphere after only 30 min.},
doi = {10.1116/1.4754292},
journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
issn = {0734-2101},
number = 6,
volume = 30,
place = {United States},
year = {2012},
month = {11}
}