Accession Number:

AD0633703

Title:

LASER PHASOGRAPHY OF JETS, SHOCKS AND PLASMAS,

Descriptive Note:

Corporate Author:

BELFER GRADUATE SCHOOL OF SCIENCE YESHIVA UNIV NEW YORK

Personal Author(s):

Report Date:

1966-04-01

Pagination or Media Count:

114.0

Abstract:

The phase-contrast microscope of Zernike may be scaled in size and combined with giant pulse ruby-laser illumination to make possible the observation of macroscopic moving tenuous objects, such as jets, shock waves and plasmas. The resulting instrument, referred to as the Laser Phase Macroscope L.P.M., has performance similar to that of an optical interferometer operated in the single-fringe mode. The operation of the phase macroscope is treated theoretically, first heuristically and then by diffraction integrals. Conditions for optimum imaging are derived. The phase plate of Zernike is modified for use with focused laser illumination, and parameters for optimum imaging are given. Quite different mirrors are required for the full range of interesting plasmas accessible to the L.P.M. The experimental model is described. Phasograms of weak and strong shocks in air and argon down to .5 mm Hg pressure are shown. Rayleigh-Taylor instability behind the shock is observed. Gas jets of various refractivities are also used as test objects. Phasograms of vacuum sparks producing jets of ablated electrode material are shown. Many objects studied are invisible to schlieren photography using the same illumination and optics. Author

Subject Categories:

  • Lasers and Masers
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE