Sensitivity studies of the ortho/para H{sub 2} concentration on the neutronic performance of the Lujan center liquid H{sub 2} moderator using state-of-the-art computational tools

PDF Version Also Available for Download.

Description

A liquid H{sub 2} moderator has been operational at the Manual Lujan Jr. Neutron Scattering Center (Lujan Center) since 1985. Detailed Monte Carlo calculations have been made to estimate the neutronic performance of the liquid H{sub 2} moderator cold source, using the state-of-the-art Los Alamos LAHET Code System and liquid H{sub 2} scattering kernels. The absolute neutron spectrum leaking from the moderator has been measured. In thermal equilibrium at 20 K, the moderator would convert to 100% para-hydrogen on some time frame. The authors show that the performance of the Lujan Center cold neutron source is sensitive to small fractions ... continued below

Physical Description

10 p.

Creation Information

Russell, G.J.; Ferguson, P.D. & Pitcher, E.J. September 1, 1998.

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.

Sponsor

Publisher

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

A liquid H{sub 2} moderator has been operational at the Manual Lujan Jr. Neutron Scattering Center (Lujan Center) since 1985. Detailed Monte Carlo calculations have been made to estimate the neutronic performance of the liquid H{sub 2} moderator cold source, using the state-of-the-art Los Alamos LAHET Code System and liquid H{sub 2} scattering kernels. The absolute neutron spectrum leaking from the moderator has been measured. In thermal equilibrium at 20 K, the moderator would convert to 100% para-hydrogen on some time frame. The authors show that the performance of the Lujan Center cold neutron source is sensitive to small fractions of ortho-hydrogen, and display these results as a function of the ortho/para H{sub 2} concentration. Integral data from the measured neuron spectrum have been combined with calculated predictions to estimate the ortho/para H{sub 2} concentration in the moderator. From these analyses, they estimate the ortho-hydrogen concentration in the liquid H{sub 2} moderator to be 6--9% at the time the neutron spectrum was measured.

Physical Description

10 p.

Notes

INIS; OSTI as DE98006322

Source

  • International workshop on cold moderators for pulsed neutron sources, Argonne, IL (United States), 28 Sep - 10 Oct 1997

Language

Item Type

Identifier

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

  • Other: DE98006322
  • Report No.: LA-UR--98-1021
  • Report No.: CONF-9709132--
  • Grant Number: W-7405-ENG-36
  • Office of Scientific & Technical Information Report Number: 674722
  • Archival Resource Key: ark:/67531/metadc711771

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

  • September 1, 1998

Added to The UNT Digital Library

  • Sept. 12, 2015, 6:31 a.m.

Description Last Updated

  • May 5, 2016, 7:20 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 3

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Russell, G.J.; Ferguson, P.D. & Pitcher, E.J. Sensitivity studies of the ortho/para H{sub 2} concentration on the neutronic performance of the Lujan center liquid H{sub 2} moderator using state-of-the-art computational tools, article, September 1, 1998; New Mexico. (digital.library.unt.edu/ark:/67531/metadc711771/: accessed October 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.