Research and Development of Photon Activated Thermionic Cathodes for Excimer Lasers.

Abstract

A combined experimental and analytical study was designed to determine whether electron emission from thermally pulsed laser heated cesiated surfaces is due to thermally non-equilibrated thermionic effects, and, if so, to provide a description of the relevant physical processes and their limitations. The experiments were performed with specific pulses of laser radiation incident on tungsten surfaces immersed in a low pressure cesium vapor. The measurements indicated that thermionically generated space charge limited currents are generated, and that their magnitudes could only be accounted for by thermal nonequilibrium effects. The rapidly rising current pulses were often observed to transition into a plasma dominated flow that could be curtailed by diode charges. These experiments and conclusions are discussed in this report in more detail. Keywords: Laser heating; Diode; Thermionic emission; Nonequilibrium; Cesium tungsten.

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1986
Accession Number
ADA180926

Entities

People

  • P. E. Oettinger

Tags

DTIC Thesaurus Topics

  • Electromagnetic Radiation
  • Electron Emission
  • Electrons
  • Emission
  • Excimer Lasers
  • Lasers
  • Measurement
  • Photoexcitation
  • Pulsed Lasers
  • Radiation
  • Space Charge
  • Thermionic Emission
  • Tungsten

Fields of Study

  • Physics

Readers

  • Optical Physics and Photonics.
  • Plasma Physics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Microelectronics
  • Space
  • Space - Hall-Effect Thruster