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Title: A retractable electron emitter for the creation of unperturbed pure electron plasmas

Abstract

A retractable electron emitter has been constructed for the creation of unperturbed pure electron plasmas on magnetic surfaces in the Columbia Non-neutral Torus stellarator. The previous method of electron emission using emitters mounted on stationary rods limited the confinement time to 20 ms. A pneumatically driven system that can retract from the magnetic axis to the last closed flux surface in less than 20 ms while filling the surfaces with electrons was designed. The motion of the retractable emitter was modeled with a system of dynamical equations. The measured position versus time of the emitter agrees well with the model and the fastest axis-to-edge retraction was measured to be 20 ms with 40 psig helium gas driving the pneumatic piston.

Authors:
; ;  [1]
  1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
Publication Date:
OSTI Identifier:
20953239
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 1; Other Information: DOI: 10.1063/1.2431090; (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; CONFINEMENT TIME; ELECTRON EMISSION; ELECTRONS; HELIUM; MAGNETIC SURFACES; MAGNETOHYDRODYNAMICS; PISTONS; PLASMA; PLASMA CONFINEMENT; PLASMA DIAGNOSTICS; PLASMA PRODUCTION; STELLARATORS

Citation Formats

Berkery, John W., Pedersen, Thomas Sunn, and Sampedro, Luis. A retractable electron emitter for the creation of unperturbed pure electron plasmas. United States: N. p., 2007. Web. doi:10.1063/1.2431090.
Berkery, John W., Pedersen, Thomas Sunn, & Sampedro, Luis. A retractable electron emitter for the creation of unperturbed pure electron plasmas. United States. doi:10.1063/1.2431090.
Berkery, John W., Pedersen, Thomas Sunn, and Sampedro, Luis. Mon . "A retractable electron emitter for the creation of unperturbed pure electron plasmas". United States. doi:10.1063/1.2431090.
@article{osti_20953239,
title = {A retractable electron emitter for the creation of unperturbed pure electron plasmas},
author = {Berkery, John W. and Pedersen, Thomas Sunn and Sampedro, Luis},
abstractNote = {A retractable electron emitter has been constructed for the creation of unperturbed pure electron plasmas on magnetic surfaces in the Columbia Non-neutral Torus stellarator. The previous method of electron emission using emitters mounted on stationary rods limited the confinement time to 20 ms. A pneumatically driven system that can retract from the magnetic axis to the last closed flux surface in less than 20 ms while filling the surfaces with electrons was designed. The motion of the retractable emitter was modeled with a system of dynamical equations. The measured position versus time of the emitter agrees well with the model and the fastest axis-to-edge retraction was measured to be 20 ms with 40 psig helium gas driving the pneumatic piston.},
doi = {10.1063/1.2431090},
journal = {Review of Scientific Instruments},
number = 1,
volume = 78,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}