Accession Number:

ADA038533

Title:

Production of Large Warm Plasmas by Staged Laser Heating of Solid Targets.

Descriptive Note:

Memorandum rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

Report Date:

1977-02-01

Pagination or Media Count:

19.0

Abstract:

A 1000 Joule CO2 laser pulse, focussed on a slowly expanding drdt 200,000 cmsec gas cloud in a vacuum chamber, ionizes the gas by laser spark breakdown, and then heats it by inverse bremstrahlung absorption. The resulting plasma contains about 10 to the 19th power ions at a temperature of approximately 50 eV. The gas cloud is created by irradiating a solid plastic target with a 10 J prepulse and a 100 J main pulse from a Ndglass laser. Two advantages of these two laser plasma production systems over irradiating a solid target directly with the CO2 laser are 1 the density of the target gas cloud in an adjustable parameter that can be used to vary the plasma temperature and total number of particles, and 2 since the temperature of an expanding plasma decreases as Tr T sub or sub or squared, and since r sub o is a factor of ten larger for a gas than a solid, the temperature at large r of a plasma that originated as a cloud is a factor of 100 higher than one that was heated at the radius of a solid, provided of course, that the initial temperature and particle number are the same in both cases. Author

Subject Categories:

  • Lasers and Masers
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE