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Title: Cryopumping of deuterium hydrogen and helium mixtures on smooth 4.2 K surfaces

Conference ·
OSTI ID:7219405

The large quantities of deuterium and hydrogen to be pumped in a fusion reactor and its subsystems favor cryopumping over other pumping methods. Cryogen consumption and the operating pressure will not only depend on the gas to be pumped, but also on the amount of helium gas present in the system. In fact, residual helium pressure between pulses will determine the power dissipation of the pump, and hence, influence the choice of cryocondensation or cryosorption. In this paper we will present the results of our studies on (1) cryotrapping of helium in thick D/sub 2/ and H/sub 2/ films and hydrogen in D/sub 2/ films at 4.2 K; (2) diffusion of He and H/sub 2/ from D/sub 2/ films; (3) steady-state liquid helium consumption; (4) liquid helium consumption as a function of D/sub 2/ and H/sub 2/ fluxes being pumped; (5) liquid helium consumption as a function of He partial pressure in the system. Finally, these measurements will suggest maximum permissible He to D/sub 2/ and He to H/sub 2/ ratios in a cryocondensation pump.

Research Organization:
Brookhaven National Lab., Upton, NY (USA)
Sponsoring Organization:
US Energy Research and Development Administration (ERDA)
DOE Contract Number:
EY-76-C-02-0016
OSTI ID:
7219405
Report Number(s):
BNL-22759; CONF-770908-3; TRN: 77-015545
Resource Relation:
Conference: 7. international Vac. congress and 3. international conference on solid surfaces, Vienna, Austria, 12 Sep 1977
Country of Publication:
United States
Language:
English