Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma

Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J.

doi:10.1063/1.4798424

Title: Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma

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Abstract

We present measurements of the scattering, reflection, absorption, and transmission of a 1.5 MW, 110 GHz quasioptical gyrotron beam by a self-induced air breakdown plasma. The breakdown forms a periodic array of plasma filaments, oriented parallel to the incident electric field polarization that propagates toward the microwave source. For incident intensity of 3 MW/cm{sup 2}, calorimetric measurements show that as much as 45% of the full beam power is absorbed by the plasma, averaged over the pulse, 1% is reflected backward, and the remainder is transmitted and also scattered into a wide angular spread. We observe that approximately 10 times more power is scattered in the direction perpendicular to the filaments than parallel. The far-field angular distribution of transmitted power exhibits a diffraction pattern that changes throughout the 2-{mu}s life of the plasma.

Authors:

Cook, Alan M.; Hummelt, Jason S.; Shapiro, Michael A.; Temkin, Richard J. ^[1]

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

Publication Date:: Mon Apr 15 00:00:00 EDT 2013

OSTI Identifier:: 22130477

Resource Type:: Journal Article

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 20; Journal Issue: 4; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABSORPTION; AIR; ANGULAR DISTRIBUTION; APPROXIMATIONS; BREAKDOWN; CALORIMETRY; DIFFRACTION; ELECTRIC FIELDS; GHZ RANGE; MICROWAVE AMPLIFIERS; MICROWAVE RADIATION; PERIODICITY; PLASMA DIAGNOSTICS; PLASMA FILAMENT; WAVE PROPAGATION

Citation Formats


                    Cook, Alan M., Hummelt, Jason S., Shapiro, Michael A., and Temkin, Richard J. Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma.  United States: N. p., 2013. 
        Web.  doi:10.1063/1.4798424.

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                    Cook, Alan M., Hummelt, Jason S., Shapiro, Michael A., & Temkin, Richard J. Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma.  United States.  https://doi.org/10.1063/1.4798424

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                    Cook, Alan M., Hummelt, Jason S., Shapiro, Michael A., and Temkin, Richard J. 2013.  
        "Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma".  United States.  https://doi.org/10.1063/1.4798424.

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@article{osti_22130477,

  title        = {Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma},

  author       = {Cook, Alan M. and Hummelt, Jason S. and Shapiro, Michael A. and Temkin, Richard J.},

  abstractNote = {We present measurements of the scattering, reflection, absorption, and transmission of a 1.5 MW, 110 GHz quasioptical gyrotron beam by a self-induced air breakdown plasma. The breakdown forms a periodic array of plasma filaments, oriented parallel to the incident electric field polarization that propagates toward the microwave source. For incident intensity of 3 MW/cm{sup 2}, calorimetric measurements show that as much as 45% of the full beam power is absorbed by the plasma, averaged over the pulse, 1% is reflected backward, and the remainder is transmitted and also scattered into a wide angular spread. We observe that approximately 10 times more power is scattered in the direction perpendicular to the filaments than parallel. The far-field angular distribution of transmitted power exhibits a diffraction pattern that changes throughout the 2-{mu}s life of the plasma.},

  doi          = {10.1063/1.4798424},

  url          = {https://www.osti.gov/biblio/22130477},
  journal      = {Physics of Plasmas},

  issn         = {1070-664X},

  number       = 4,

  volume       = 20,

  place        = {United States},

  year         = {Mon Apr 15 00:00:00 EDT 2013},

  month        = {Mon Apr 15 00:00:00 EDT 2013}

}

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