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A Dust Grain Photoemission ExperimentA laboratory experiment has been developed at Marshall Space Flight Center to study the interaction of micron-sized particles with plasmas and FUV radiation. The intent is to investigate the conditions under which particles of various compositions and sizes become charged, or discharged, while exposed to an electron beam and/or UV radiation. This experiment uses a unique laboratory where a single charged micron size particle is suspended in a quadrupole trap and then subjected to a controlled environment. Tests are performed using different materials and sizes, ranging from 10 microns to 1 micron, to determine the particle's charge while being subjected to an electron beam and /or UV radiation. The focus of this presentation will be on preliminary results from UV photoemission tests, but past results from electron beam, secondary electron emission tests will also be highlighted. A monochromator is used to spectrally resolve UV in the 120 nm to 300 nm range. This enables photoemission measurements as a function of wavelength. Electron beam tests are conducted using I to 3 micron sized aluminum oxide particles subjected to energies between 100 eV to 3 KeV. It was found that for both positive and negative particles the potential tended toward neutrality over time with possible equilibrium potentials between -0.8 Volts and 0.8 Volts.
Document ID
20000074963
Document Type
Preprint (Draft being sent to journal)
Authors
Venturini, C. C. (Alabama Univ. Huntsville, AL United States)
Spann, J. F., Jr. (NASA Marshall Space Flight Center Huntsville, AL United States)
Abbas, M. M. (NASA Marshall Space Flight Center Huntsville, AL United States)
Comfort, R. H. (Alabama Univ. Huntsville, AL United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 2000
Subject Category
Plasma Physics
Meeting Information
Physics of Dusty Plasmas(Santa Fe, NM)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.