Pumping characteristics of a cryopump with Ar sorbent in He and in D{sub 2}/He mixture

PDF Version Also Available for Download.

Description

The He ash generated as a result of D/T burn in a fusion reactor must be exhausted from the plasma to avoid fuel dilution effects. In view of this, transport and exhaust studies of He in fusion plasmas are getting increasing attention in recent years. In fusion plasmas, the exhaust gas will be a combination of D{sub 2} and He, with He forming only a small fraction (about 10 %). The authors have investigated the cryosorption pumping characteristics of pure He and a mixture of D{sub 2} and He (90 % D{sub 2}) using a cryosorption pump with condensed layers ... continued below

Physical Description

14 p.

Creation Information

Menon, M. M.; Wade, M. R.; Maingi, R.; Hillis, D. L.; Laughon, G. J. & Mahdavi, M. A. February 1, 1995.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Authors

Sponsor

Publishers

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

The He ash generated as a result of D/T burn in a fusion reactor must be exhausted from the plasma to avoid fuel dilution effects. In view of this, transport and exhaust studies of He in fusion plasmas are getting increasing attention in recent years. In fusion plasmas, the exhaust gas will be a combination of D{sub 2} and He, with He forming only a small fraction (about 10 %). The authors have investigated the cryosorption pumping characteristics of pure He and a mixture of D{sub 2} and He (90 % D{sub 2}) using a cryosorption pump with condensed layers of Ar as sorbent. A cryocondensation pump cooled by liquid He at 4.3 K, and located in the outboard divertor region of the DIII-D tokamak, was used for the experiment. The investigation was conducted in a pressure regime that is relevant for particle exhaust from fusion plasmas. The experiment revealed that: (1) cryosorption pumping speed of pure He drops precipitously if the Ar/He ratio falls below about 20; (2) the pumping speed for He in a D{sub 2}/He mixture decreases in an exponential manner with the amount of D{sub 2} pumped; (3) increasing the thickness of Ar in the range of 1 - 12 {mu}m had little effect on the pumping speed for He in a D{sub 2}/He mixture; and (4) for a pumping surface coated with a thick (>2 {mu}m) layer of Ar, surrounded by a radiation shield having a transparency factor of about 6, a He pumping speed in the range of 15-25 m{sup 3}s{sup {minus}l}m{sup {minus}2}, in the millitorr pressure range for pulse duration of about 5 s can be obtained after pumping about 80 torr 1 of D{sub 2}.

Physical Description

14 p.

Notes

OSTI; NTIS; GPO Dep.

Source

  • 41. annual American Vacuum Society symposium,Denver, CO (United States); Denver, CO (United States),24-28 Oct 1994; 24-28 Oct 1994

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Other: DE95007049
  • Report No.: CONF-941001--11
  • Report No.: CONF-9410295--1
  • Grant Number: AC05-84OR21400
  • Grant Number: AC03-89ER51114
  • Office of Scientific & Technical Information Report Number: 10120127
  • Archival Resource Key: ark:/67531/metadc1278339

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • February 1, 1995

Added to The UNT Digital Library

  • Oct. 12, 2018, 6:44 a.m.

Description Last Updated

  • Nov. 29, 2018, 2:43 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 1
Total Uses: 1

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Menon, M. M.; Wade, M. R.; Maingi, R.; Hillis, D. L.; Laughon, G. J. & Mahdavi, M. A. Pumping characteristics of a cryopump with Ar sorbent in He and in D{sub 2}/He mixture, article, February 1, 1995; United States. (https://digital.library.unt.edu/ark:/67531/metadc1278339/: accessed March 18, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.