Accession Number:

AD0694437

Title:

MODIFICATION OF PLASMA BY RAPIDLY EVAPORATING LIQUID ADDITIVES.

Descriptive Note:

Semi-Annual rept.,

Corporate Author:

SPACE SCIENCES INC WALTHAM MASS

Personal Author(s):

• Aisenberg,Sol
• Chang,K. W.
• Hu,Pung N.

Report Date:

1969-04-01

Pagination or Media Count:

68.0

Abstract:

Previous experimental results have shown that liquid additives aspirated into plasma resulted in almost complete recovery of the microwave transmission. In the present study, possible electron removal mechanisms of the liquid additive are investigated theoretically and experimentally. These mechanisms include vaporization of negatively charged molecules, the electron attachment of the vapor as well as the microwave transmission through a highly inhomogeneous plasma. Effects of surface tension and the electrostatic potential of the droplet on the heat of vaporization are analyzed the former is found negligible and the latter important for droplets of micron or submicron sizes. The survival time and distance are studied by considering the vaporization and the acceleration of the droplet for various droplet sizes and additives and the results are then used to determine the electron density along the plasma stream. Measurements are made for the microwave transmission through a synthetic porous plasma for various parameter ranges. Preliminary results agree very well with the previous experimental results on plasma jets and show that appreciable microwave transmission can be obtained through a porous plasma. One interesting conclusion is that it is better to remove free electrons in clumps or pores rather than to remove the same number of electrons uniformly throughout the plasma. Author

Descriptors:

• *MICROWAVE COMMUNICATIONS
• *PLASMAS(PHYSICS)
• BLACKOUT(PROPAGATION)
• ADDITIVES
• LIQUIDS
• ELECTRON DENSITY
• DROPS
• MICROWAVES

Subject Categories:

• Plasma Physics and Magnetohydrodynamics
• Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE