Liquid Helium Cooled Balloon-Borne Grating Spectrometer System.

Abstract

A Littrow grating spectrometer designed to operate in a liquid helium dewar at a temperature of 4K was constructed as the major effort in this program. The problems associated with construction of such an instrument and the methods used to solve them are discussed. The spectrometer was designed to be used on a balloon-borne platform and to measure the atmospheric emission as a function of wavelength and altitude. Use of the spectrometer in this fashion requires that the liquid helium dewar used to house the spectrometer be equipped with an appropriate infrared window. This window is a source of background noise for the spectrometer and in order to achieve sensitivity the window is cooled by liquid nitrogen to 77K. Techniques for keeping atmospheric H2O and CO2 from freezing on to the window were developed and incorporated into the final balloon-borne system.

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1974
Accession Number
ADA002009

Entities

People

  • David G. Murcray
  • James N. Brooks
  • John J. Kosters
  • Walter J. Williams

Organizations

  • University of Denver

Tags

DTIC Thesaurus Topics

  • Altitude
  • Background Noise
  • Construction
  • Emission
  • Freezing
  • Infrared Windows
  • Nitrogen
  • Noise
  • Platforms
  • Sensitivity
  • Spectrometers
  • Transition Temperature
  • Windows

Fields of Study

  • Environmental science

Readers

  • Astronomy and Astrophysics.
  • Optical Physics and Photonics.
  • Thermal Physics or Thermal Science.