Laser Plasma Particle Velocities
Abstract
Experiments were performed on laser produced plasma from aluminum target discs in a vacuum chamber at pressures a few times (10 to the (-6) power) torr. Plasma analysis was achieved using a floating double electrostatic probe of tungsten wires biased at -15 volts DC. In analyzing 376 oscilloscope trace pictures of the probe signal, four velocity signals occurred with regularity. The plasma velocities detected by the probe were determined to be 3.7 X (10 to the 7th power) cm/sec, 1.5 X (10 to the 7th power) cm/sec, 5.6 X (10 to the 6th power) cm/sec (the bulk of the plasma), and 4.0 X (10 to the 6th power) cm/sec. A fifth, very fast signal at 1.0 X (10 to the 8th power) cm/sec was also detected but it was not consistently present. Investigation of the velocity distributions as a function of time showed them not to be Boltzmann distributions, but exponential power distributions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1976
- Accession Number
- ADA030079
Entities
People
- Daniel J. Callahan
Organizations
- Naval Postgraduate School