In:
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, American Vacuum Society, Vol. 3, No. 3 ( 1985-05-01), p. 1684-1689
Abstract:
The need to simulate the conditions of outer space, beginning in 1960, created a requirement for large cryopumps to maintain near-space conditions in large chambers. A variety of cryogenic support systems including both pressurized and boiling liquid nitrogen systems, and helium refrigerators, normally operating near 20 K were required. The fusion program provided a similar, but more stringent, requirement. Here, hydrogen isotopes had to be removed from fusion chambers and neutral beam systems. This resulted in a new group of cryopump arrays having very high speeds. In this case liquid helium systems are required, either boiling with natural convection, or force fed from a refrigerator. More sophisticated Monte Carlo calculation methods were developed, which enabled the prediction of gross pumping speed, and localized pressures, taking into account the temperatures of surrounding surfaces and gas feed location.
Type of Medium:
Online Resource
ISSN:
0734-2101
,
1520-8559
Language:
English
Publisher:
American Vacuum Society
Publication Date:
1985
detail.hit.zdb_id:
1475424-1
detail.hit.zdb_id:
797704-9
