Spectroscopic temperature measurements of air breakdown plasma using a 110 GHz megawatt gyrotron beam

Journal Article · Sat Dec 15 00:00:00 EST 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4773037· OSTI ID:22072671

Hummelt, J S; Shapiro, M A; Temkin, R J ^[1]

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1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

Temperature measurements are presented of a non-equilibrium air breakdown plasma using optical emission spectroscopy. A plasma is created with a focused 110 GHz 3 {mu}s pulse gyrotron beam in air that produces power fluxes exceeding 1 MW/cm{sup 2}. Rotational and vibrational temperatures are spectroscopically measured over a pressure range of 1-100 Torr as the gyrotron power is varied above threshold. The temperature dependence on microwave field as well as pressure is examined. Rotational temperature measurements of the plasma reveal gas temperatures in the range of 300-500 K and vibrational temperatures in the range of 4200-6200 K. The vibrational and rotational temperatures increase slowly with increasing applied microwave field over the range of microwave fields investigated.

• OSTI ID: 22072671
• Journal Information: Physics of Plasmas, Vol. 19, Issue 12; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AIR
BEAMS
BREAKDOWN
EMISSION SPECTROSCOPY
GHZ RANGE
MICROWAVE AMPLIFIERS
MICROWAVE RADIATION
PLASMA
PLASMA PRODUCTION
PRESSURE RANGE
ROTATIONAL STATES
TEMPERATURE DEPENDENCE
TEMPERATURE MEASUREMENT
VIBRATIONAL STATES