Publication detail

Economical helium bath cryopump: design and testing

Musilová Věra, Dupák Jan, Hanzelka Pavel, Králík Tomáš, Urban Pavel

Original Title

Economical helium bath cryopump: design and testing

Type

journal article - other

Language

English

Original Abstract

A small UHV helium bath cryopump with low cryoliquid consumption has been designed, manufactured and tested. The cryopump is designed to keep UHV in electron optical devices without generation of disturbing electromagnetic fields or vibrations. The outer volume of its shell is 15 l, the filling volumes of liquid helium (LHe) and liquid nitrogen (LN2) are 3.0 l and 3.4 l, respectively. Operating times between cryoliquid fillings are 35 days for LHe and 6 days for LN2. A pump speed of 25 l/s was measured for the He gas. A lowest pressure of 1.5,10,7 Pa was achieved in a test chamber and the pumping tests indicated that an even lower pressure would be achieved in a well-degassed chamber. Good agreement between the calculated and measured values both of the pump speed and the cryoliquid evaporation has been found. The system of chevron-type baffles was designed and checked by Monte Carlo simulations of molecular flow and radiative heat transfer. The pump prototype was successfully used to evacuate an operating cryostat of a NMR spectrometer.

Key words in English

Cryopump; Molecular flow; Radiative heat transfer; Cryogenic optimisation; Monte Carlo particle tracing

Authors

Musilová Věra, Dupák Jan, Hanzelka Pavel, Králík Tomáš, Urban Pavel

Released

3. 5. 2004

ISBN

0042-207X

Periodical

Vacuum

Year of study

2004

Number

74

State

United Kingdom of Great Britain and Northern Ireland

Pages from

77

Pages to

83

Pages count

7

URL

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW4-4BHV85H-8&_user=2654390&_handle=V-WA-A-W-AZ-MsSAYWW-UUW-U-AAWCUCYBCW-AAWWZBEACW-WCUBAEAWY-AZ-U&_fmt=full&_coverDate=05%2F03%2F2004&_rdoc=8&_orig=browse&_srch=%23toc%235552%232004%23999259998%23496357!&_cdi=5552&view=c&_acct=C000058444&_version=1&_urlVersion=0&_userid=2654390&md5=8c43f958caf972caf17a35aceb2e3423

BibTex

@article{BUT42434,
  author="Pavel {Urban}",
  title="Economical helium bath cryopump: design and testing",
  journal="Vacuum",
  year="2004",
  volume="2004",
  number="74",
  pages="7",
  issn="0042-207X",
  url="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW4-4BHV85H-8&_user=2654390&_handle=V-WA-A-W-AZ-MsSAYWW-UUW-U-AAWCUCYBCW-AAWWZBEACW-WCUBAEAWY-AZ-U&_fmt=full&_coverDate=05%2F03%2F2004&_rdoc=8&_orig=browse&_srch=%23toc%235552%232004%23999259998%23496357!&_cdi=5552&view=c&_acct=C000058444&_version=1&_urlVersion=0&_userid=2654390&md5=8c43f958caf972caf17a35aceb2e3423"
}