INFRARED MASER INTERFEROMETRY FOR TIME AND SPACE RESOLUTION OF ELECTRON DENSITY IN HIGH TEMPERATURE PLASMAS.
Abstract
A 3.39 micron He-Ne maser excited infrared interferometer was utilized for the investigation of time and space resolved electron density in a high temperature, dense plasma formed in the 'theta-pinch' geometry. Dispersion of the coherent infrared radiation by the plasma electrons within an external resonator pulls the frequency of the coupled maser resonator with a resultant change in intensity. A spherical mirror focuses the maser beam at the center of a 20 cm length coil. The depth of focus is such that the beam diameter is less than 1 mm over the length of the plasma contained in a 46 mm ID Pyrix plasma tube with quartz end windows. The external resonator is formed by placing a second spherical reflector's radius of curvature. This spherical reflector returns the maser beam upon itself; its position is such that refraction effects by electron density gradients in the plasma are minimized. In order that the maser modulation might have a well defined waveshape and wide bandwidth, the resonators are operated with low coupling and at a relatively low Q. The maximum measurable electron density time variation of 3 times 10 to th 16th power/cubic cm microns is achieved with a fast In As infrared detector.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1964
- Accession Number
- AD0800736
Entities
People
- Arwin Adelbert Dougal
- J. P. Craig
- Robert Fonda Gribble
Organizations
- University of Texas at Austin