Phase Transition Cooled Window Studies for High Average Power Electron Guns

Abstract

The window used to transmit electron beams for use in high average power UV/visible lasers has been a critical technology issue. The window structure must satisfy a number of conflicting requirements including: vacuum integrity, strength to overcome both the static and dynamic pressure loads of the laser gas and a low mass density to minimize energy loss by the electron beam. In addition, it must not perturb the laser gas flow and must be able to dissipate the power deposited by the electron beam. Two experiments were undertaken to demonstrate the applicability of phase transition cooling for high power laser systems. In the first of these a full width 50 cm module was tested with a constant input heat source. The second experiment used a pulsed e-beam source to demonstrate cooling for a low duty cycle high peak power pulsed system. The applicability of phase transition cooling for a dual foil geometry was clearly demonstrated. Cooling rates in excess of 100 W/(sq cm)/foil surface with mass flow rates consistent with low areal mass density were achieved. This represents a factor of ten improvement over prexisting state of the art. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1980
Accession Number
ADA100630

Entities

People

  • D. Forcier
  • G. Loda

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aspect Ratio
  • Barometric Pressure
  • Electron Beams
  • Energy
  • Gas Flow
  • Heat Energy
  • Heat Of Vaporization
  • Heat Transfer
  • Heat Transmission
  • Light Scattering
  • Materials
  • Measurement
  • Phase Transformations
  • Spray Nozzles
  • Surface Temperature
  • Thermal Conductivity
  • Vaporization

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Nanofabrication and Microfabrication.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Microelectronics