skip to main content

SciTech ConnectSciTech Connect

Title: Plasma relaxation mechanics of pulsed high power microwave surface flashover

Microwave transmission and reflection characteristics of pulsed radio frequency field generated plasmas are elucidated for air, N{sub 2}, and He environments under pressure conditions ranging from 10 to 600 torr. The pulsed, low temperature plasma is generated along the atmospheric side of the dielectric boundary between the source (under vacuum) and the radiating environment with a thickness on the order of 5 mm and a cross sectional area just smaller than that of the waveguide. Utilizing custom multi-standard waveguide couplers and a continuous low power probing source, the scattering parameters were measured before, during, and after the high power microwave pulse with emphasis on the latter. From these scattering parameters, temporal electron density estimations (specifically the longitudinal integral of the density) were calculated using a 1D plane wave-excited model for analysis of the relaxation processes associated. These relaxation characteristics ultimately determine the maximum repetition rate for many pulsed electric field applications and thus are applicable to a much larger scope in the plasma community than just those related to high power microwaves. This manuscript discusses the diagnostic setup for acquiring the power measurements along with a detailed description of the kinematic and chemical behavior of the plasma as it decaysmore » down to its undisturbed state under various gas type and pressure conditions.« less
Authors:
; ;  [1]
  1. Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)
Publication Date:
OSTI Identifier:
22220642
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 9; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AIR; DIELECTRIC MATERIALS; ELECTRIC FIELDS; ELECTRON DENSITY; ELECTRON TEMPERATURE; FLASHOVER; HELIUM; HIGH-FREQUENCY DISCHARGES; ION TEMPERATURE; MICROWAVE RADIATION; NITROGEN; PLASMA DENSITY; PLASMA DIAGNOSTICS; PULSES; RADIOWAVE RADIATION; RELAXATION; SCATTERING; WAVE PROPAGATION; WAVEGUIDES