Design and Construction of a Gamma Reaction History Diagnostic for the National Ignition Facility

PDF Version Also Available for Download.

Description

Gas Cherenkov detectors have been used to convert fusion gammas into photons to achieve gamma reaction history (GRH) measurements. These gas detectors include a converter, pressurized gas volume, relay optics, and a photon detector. A novel design for the National Ignition Facility (NIF) using 90º Off-Axis Parabolic mirrors efficiently collects signal from fusion gammas with 8-ps time dispersion.1 Fusion gammas are converted to Compton electrons, which generate broadband Cherenkov light (our response is from 250 to 700 nm) in a pressurized gas cell. This light is relayed into a high-speed detector using three parabolic mirrors. The detector optics collect light ... continued below

Creation Information

R.M. Malone, B.C. Cox, B.C. Frogget, M.I. Kaufman, T.W. Tunnell; H.W. Herrmann, S.C. Evans, J.M. Mack, C.S. Young & Stoeffl, W. June 5, 2009.

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

Gas Cherenkov detectors have been used to convert fusion gammas into photons to achieve gamma reaction history (GRH) measurements. These gas detectors include a converter, pressurized gas volume, relay optics, and a photon detector. A novel design for the National Ignition Facility (NIF) using 90º Off-Axis Parabolic mirrors efficiently collects signal from fusion gammas with 8-ps time dispersion.1 Fusion gammas are converted to Compton electrons, which generate broadband Cherenkov light (our response is from 250 to 700 nm) in a pressurized gas cell. This light is relayed into a high-speed detector using three parabolic mirrors. The detector optics collect light from a 125-mm-diameter by 600-mm-long interchangeable gas (CO2 or SF6) volume. Because light is collected from source locations throughout the gas volume, the detector is positioned at the stop position rather than at an image position. The stop diameter and its position are independent of the light-generation locations along the gas cell. This design incorporates a fixed time delay that allows the detector to recover from prompt radiation. Optical ray tracings demonstrate how light can be collected from different angled trajectories of the Compton electrons as they traverse the gas volume. A Monte Carlo model of the conversion process from gammas to Cherenkov photons is used to generate photon trajectories. The collection efficiencies for different gamma energies are evaluated. At NIF, a cluster of four channels will allow for increased dynamic range, as well as different gamma energy thresholds. This GRH design is compared to a gas Cherenkov detector that utilizes a Cassegrain reflector now used at the OMEGA laser facility. 1. R. M. Malone, H. W. Herrmann, W. Stoeffl, J. M. Mack, C. S. Young, “Gamma bang time/reaction history diagnostics for the National Ignition Facility using 90º off-axis parabolic mirrors,” Rev. Sci. Instrum. 79, 10E532 (2008).

Source

  • 36th International Conference on Plasma Science (ICOPS) and 23rd Symposium on Fusion Engineering (SOFE); San Diego, California; May 31-June 5, 2009

Language

Item Type

Identifier

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

  • Report No.: DOE/NV/25946--732
  • Grant Number: DE-AC52-06NA25946
  • Office of Scientific & Technical Information Report Number: 961544
  • Archival Resource Key: ark:/67531/metadc931106

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

  • June 5, 2009

Added to The UNT Digital Library

  • Nov. 13, 2016, 7:26 p.m.

Description Last Updated

  • Feb. 20, 2017, 2:07 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Enlarge

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

R.M. Malone, B.C. Cox, B.C. Frogget, M.I. Kaufman, T.W. Tunnell; H.W. Herrmann, S.C. Evans, J.M. Mack, C.S. Young & Stoeffl, W. Design and Construction of a Gamma Reaction History Diagnostic for the National Ignition Facility, article, June 5, 2009; United States. (digital.library.unt.edu/ark:/67531/metadc931106/: accessed July 22, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.