Abstract
The focused high-intensity beam from a Q-spoiled laser has been used to form a high-temperature, high-density plasma from a single 10-20 micron radius solid particle of lithium hydride which is electrically suspended in a vacuum environment free of all material supports. Time-resolved charge collection measurements of the freely expanding plasma have shown that a high degree of ionization of the 10{sup 15} atoms in the lithium hydride particle can be achieved and that the plasma produced is essentially spherically symmetric in density over the full 4 {pi} solid angle. Time-of-flight studies of the plasma expansion have shown that average electron and ion energies exceeding 200 electron volts are obtained and that the plasma expansion rate, like the plasma density, is spherically symmetric. No charge separation or separation of the lithium and hydrogen ions is observed in the expanding plasma. Numerical calculations of the plasma formation and expansion have been made using a one-dimensional spherical hydrodynamic model and, on the basis of the results obtained, an integrated similarity model has been developed for calculations of the plasma time history and energy over the range of conditions employed in the experiments. These calculations, which include the effects of laser pulse time history,
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Haught, A. F.;
Polk, D. H.;
Fader, W. J.
[1]
- United Aircraft Research Laboratories East Hartford, CT (United States)
Citation Formats
Haught, A. F., Polk, D. H., and Fader, W. J.
Production and Magnetic Field Confinement of Laser-Irradiated Solid Particle Plasmas.
IAEA: N. p.,
1969.
Web.
Haught, A. F., Polk, D. H., & Fader, W. J.
Production and Magnetic Field Confinement of Laser-Irradiated Solid Particle Plasmas.
IAEA.
Haught, A. F., Polk, D. H., and Fader, W. J.
1969.
"Production and Magnetic Field Confinement of Laser-Irradiated Solid Particle Plasmas."
IAEA.
@misc{etde_22106266,
title = {Production and Magnetic Field Confinement of Laser-Irradiated Solid Particle Plasmas}
author = {Haught, A. F., Polk, D. H., and Fader, W. J.}
abstractNote = {The focused high-intensity beam from a Q-spoiled laser has been used to form a high-temperature, high-density plasma from a single 10-20 micron radius solid particle of lithium hydride which is electrically suspended in a vacuum environment free of all material supports. Time-resolved charge collection measurements of the freely expanding plasma have shown that a high degree of ionization of the 10{sup 15} atoms in the lithium hydride particle can be achieved and that the plasma produced is essentially spherically symmetric in density over the full 4 {pi} solid angle. Time-of-flight studies of the plasma expansion have shown that average electron and ion energies exceeding 200 electron volts are obtained and that the plasma expansion rate, like the plasma density, is spherically symmetric. No charge separation or separation of the lithium and hydrogen ions is observed in the expanding plasma. Numerical calculations of the plasma formation and expansion have been made using a one-dimensional spherical hydrodynamic model and, on the basis of the results obtained, an integrated similarity model has been developed for calculations of the plasma time history and energy over the range of conditions employed in the experiments. These calculations, which include the effects of laser pulse time history, fraction of the incident beam occupied by the expanding plasma, radial density and velocity gradients within the plasma, and spatial distribution of the incident laser energy, give results for the plasma radial density distribution, velocity profile, and plasma energy in good agreement with those determined experimentally over the full range of the present measurements. Measurements have been carried out to examine the interaction of these laser -produced plasmas with mirror, cusp, and minimum-B magnetic fields. Experiments with mirror and minimum-B magnetic fields up to 8 kC show that plasmas with densities of 10{sup 12} -10{sup 13} cm{sup -3} are confined for times of 5 {mu}s (mirror) and 10 {mu}s (minimum-B) and that a measurable amount of plasma is still present within the containment volume at times as late as 20 {mu}s (mirror) and 100 {mu}s (minimum-B), compared with the 0.3 {mu}s 'lifetime' associated with the free plasma expansion. The plasma decay rate in the 8 kG minimum-B magnetic field is consistent with that for Coulomb collisional scattering loss into the .magnetic-field loss cones. (author)}
place = {IAEA}
year = {1969}
month = {Jan}
}
title = {Production and Magnetic Field Confinement of Laser-Irradiated Solid Particle Plasmas}
author = {Haught, A. F., Polk, D. H., and Fader, W. J.}
abstractNote = {The focused high-intensity beam from a Q-spoiled laser has been used to form a high-temperature, high-density plasma from a single 10-20 micron radius solid particle of lithium hydride which is electrically suspended in a vacuum environment free of all material supports. Time-resolved charge collection measurements of the freely expanding plasma have shown that a high degree of ionization of the 10{sup 15} atoms in the lithium hydride particle can be achieved and that the plasma produced is essentially spherically symmetric in density over the full 4 {pi} solid angle. Time-of-flight studies of the plasma expansion have shown that average electron and ion energies exceeding 200 electron volts are obtained and that the plasma expansion rate, like the plasma density, is spherically symmetric. No charge separation or separation of the lithium and hydrogen ions is observed in the expanding plasma. Numerical calculations of the plasma formation and expansion have been made using a one-dimensional spherical hydrodynamic model and, on the basis of the results obtained, an integrated similarity model has been developed for calculations of the plasma time history and energy over the range of conditions employed in the experiments. These calculations, which include the effects of laser pulse time history, fraction of the incident beam occupied by the expanding plasma, radial density and velocity gradients within the plasma, and spatial distribution of the incident laser energy, give results for the plasma radial density distribution, velocity profile, and plasma energy in good agreement with those determined experimentally over the full range of the present measurements. Measurements have been carried out to examine the interaction of these laser -produced plasmas with mirror, cusp, and minimum-B magnetic fields. Experiments with mirror and minimum-B magnetic fields up to 8 kC show that plasmas with densities of 10{sup 12} -10{sup 13} cm{sup -3} are confined for times of 5 {mu}s (mirror) and 10 {mu}s (minimum-B) and that a measurable amount of plasma is still present within the containment volume at times as late as 20 {mu}s (mirror) and 100 {mu}s (minimum-B), compared with the 0.3 {mu}s 'lifetime' associated with the free plasma expansion. The plasma decay rate in the 8 kG minimum-B magnetic field is consistent with that for Coulomb collisional scattering loss into the .magnetic-field loss cones. (author)}
place = {IAEA}
year = {1969}
month = {Jan}
}