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Title: Neutral particle analyzer measurements on the SSPX spheromak

Abstract

A neutral particle analyzer is used to measure the time-resolved energy spectrum of neutral hydrogen leaving a spheromak plasma. A gas cell filled with 10-50 mTorr of helium is used to strip electrons from incoming neutral hydrogen, lowering the minimum detectable energy well below that obtained with thin foils. Effective neutral particle temperature is calculated by fitting a Maxwellian energy distribution to the measured energy spectrum above and below {approx}300 eV. A computational model with approximated profiles of plasma density and neutral density is used with the measured neutral hydrogen flux to estimate the ion temperature. Measurement of the power flux due to neutral hydrogen emitted at the measurement location is extended to the whole plasma surface to estimate the total charge exchange power loss from the plasma. The initial results indicate that the charge exchange power loss represents only 2% of the total input gun power during the sustainment phase of the discharge.

Authors:
; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [2];  [3]
  1. Florida A and M University, Tallahassee, Florida 32310 (United States)
  2. (Russian Federation)
  3. (United States)
Publication Date:
OSTI Identifier:
20953442
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 5; Other Information: DOI: 10.1063/1.2737756; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CHARGE EXCHANGE; ELECTRON TEMPERATURE; ELECTRONS; ENERGY SPECTRA; EV RANGE; HELIUM; HYDROGEN; ION TEMPERATURE; NEUTRAL PARTICLE ANALYZERS; NEUTRAL PARTICLES; PLASMA; PLASMA CONFINEMENT; PLASMA DENSITY; PLASMA DIAGNOSTICS; POWER LOSSES; SSPX DEVICE; TIME RESOLUTION

Citation Formats

Mezonlin, E. D., Roberson, S., Raynor, C., Appartaim, R., Johnson, J. A. III, Afanasyev, V. I., Kozlovsky, S. S., Moller, J. M., Hill, D. N., Hooper, E. B., McLean, H. S., Wood, R. D., Ioffe Physico-Technical Institute, St. Petersburg, St. Petersburg State Polytechnic University, St. Petersburg, and Lawrence Livermore National Laboratory, Livermore, California. Neutral particle analyzer measurements on the SSPX spheromak. United States: N. p., 2007. Web. doi:10.1063/1.2737756.
Mezonlin, E. D., Roberson, S., Raynor, C., Appartaim, R., Johnson, J. A. III, Afanasyev, V. I., Kozlovsky, S. S., Moller, J. M., Hill, D. N., Hooper, E. B., McLean, H. S., Wood, R. D., Ioffe Physico-Technical Institute, St. Petersburg, St. Petersburg State Polytechnic University, St. Petersburg, & Lawrence Livermore National Laboratory, Livermore, California. Neutral particle analyzer measurements on the SSPX spheromak. United States. doi:10.1063/1.2737756.
Mezonlin, E. D., Roberson, S., Raynor, C., Appartaim, R., Johnson, J. A. III, Afanasyev, V. I., Kozlovsky, S. S., Moller, J. M., Hill, D. N., Hooper, E. B., McLean, H. S., Wood, R. D., Ioffe Physico-Technical Institute, St. Petersburg, St. Petersburg State Polytechnic University, St. Petersburg, and Lawrence Livermore National Laboratory, Livermore, California. Tue . "Neutral particle analyzer measurements on the SSPX spheromak". United States. doi:10.1063/1.2737756.
@article{osti_20953442,
title = {Neutral particle analyzer measurements on the SSPX spheromak},
author = {Mezonlin, E. D. and Roberson, S. and Raynor, C. and Appartaim, R. and Johnson, J. A. III and Afanasyev, V. I. and Kozlovsky, S. S. and Moller, J. M. and Hill, D. N. and Hooper, E. B. and McLean, H. S. and Wood, R. D. and Ioffe Physico-Technical Institute, St. Petersburg and St. Petersburg State Polytechnic University, St. Petersburg and Lawrence Livermore National Laboratory, Livermore, California},
abstractNote = {A neutral particle analyzer is used to measure the time-resolved energy spectrum of neutral hydrogen leaving a spheromak plasma. A gas cell filled with 10-50 mTorr of helium is used to strip electrons from incoming neutral hydrogen, lowering the minimum detectable energy well below that obtained with thin foils. Effective neutral particle temperature is calculated by fitting a Maxwellian energy distribution to the measured energy spectrum above and below {approx}300 eV. A computational model with approximated profiles of plasma density and neutral density is used with the measured neutral hydrogen flux to estimate the ion temperature. Measurement of the power flux due to neutral hydrogen emitted at the measurement location is extended to the whole plasma surface to estimate the total charge exchange power loss from the plasma. The initial results indicate that the charge exchange power loss represents only 2% of the total input gun power during the sustainment phase of the discharge.},
doi = {10.1063/1.2737756},
journal = {Review of Scientific Instruments},
number = 5,
volume = 78,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
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