Accession Number:

AD0847659

Title:

Shock Production, Langmuir Probe Diagnostics, and Instabilities in a Nitrogen Plasma.

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

• Andrews, Roger Charles

Report Date:

1968-06-01

Pagination or Media Count:

81.0

Abstract:

In conjunction with the production of large amplitude Alfven waves in a nitrogen plasma, diagnostic measurements utilizing a single Langmuir probe were made with the plasma facility operating in the reflex arc configuration. The power supply used to produce an alternating magnetic flux in a coil wrapped about the longitudinal axis of the plasma column was inadequate to produce waves of sufficient amplitude for examination. Measurement of the characteristics of the nitrogen plasma was complicated by instabilities, which were identified as 360 cps modulation of the plasma and a rotational instability rotating in a right handed direction with respect to the longitudinal magnetic field. The rotational instability is composed of inner Approx. 20kc and outer Approx. 200kc lobes whose rotational frequencies are directly proportional to magnetic field strength. For intermediate parameters B 2400 gauss the maximum electron temperature 4.2 plus or minus 0.2 eV and density 5 x 10 to the -12th powercc were determined from the instability-modulated Langmuir probe characteristic. The minimum values were about a factor of two less, indicating a significant degree of instability. Author

Descriptors:

• *SHOCK WAVES
• *PLASMAS(PHYSICS)
• NITROGEN
• LANGMUIR PROBES
• STABILITY
• MAGNETOHYDRODYNAMICS
• MAGNETIC FIELDS
• THESES

Subject Categories:

• Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE