Critical layer penetration in a cold Z-pinch plasma by high-intensity 10.6 microns laser radiation
Abstract
The intensity dependence of transmission of high-intensity 10.6 microns laser radiation through an overdense cold Z-pinch plasma has been measured to determine a threshold for transmission. A holographic cinema of plasma evolution, obtained independently of the CO2 laser, provided initial information about the target plasma. An intensity threshold for transmission was measured to be about 2.5 x 10 to the 11 W/sq cm for incidence on the pre-pinch plasma, and 2 x 10 to the eleven W/sq cm for the post-pinch plasma. As the laser intensity was increased above threshold, compression of the transmitted pulse was observed from its incident width of 38 nsec to a transmitted width of 15 nsec at maximum intensity of 4 x 10 to the eleven W/cm. Coincidence measurements between the incident and transmitted pulse indicated the blockage of the first portion of the pulse and subsequent transmission of the remainder. Analysis of the laser-induced shock indicated about 60 to 70 percent energy absorption. Enhanced optical continuum emission from the interaction volume was attributed to plasma heating.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- September 1977
- Bibcode:
- 1977PhDT........25A
- Keywords:
-
- Carbon Dioxide Lasers;
- Light (Visible Radiation);
- Plasma Pinch;
- Threshold Detectors (Dosimeters);
- Diffraction;
- Electromagnetic Fields;
- Holography;
- Light Transmission;
- Plasma Heating;
- Plasma Physics