Ion temperature measurements on TMX-U using a gridless electrostatic analyzer

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Review of Scientific Instruments; (USA)

DOI:https://doi.org/10.1063/1.1141114· OSTI ID:6756855

Falabella, S; Molvik, A W ^[1]

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1. Lawrence Livermore National Laboratory, Livermore, California 94551 (USA)

A small retarding-potential analyzer was used on the Tandem Mirror Experiment-Upgrade (TMX-U) to investigate the radial profiles of ion temperature, density, and plasma potential during ion cyclotron resonance heating (ICRH). The analyzer uses the magnetic field of TMX-U, rather than biased grids, to prevent electrons from reaching the biased ion collector. The probe, the Radial Energy Analyzer (REA), has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3{times}10{sup 12} cm{sup {minus}3} without damage to the probe or major degradation of the plasma. This analyzer measured an increase in ion temperature from 20 to 150 eV with 60 kW of ICRH. The REA measurements agree with other diagnostics on TMX-U. A one-dimensional code was written to investigate the effect of space charge on the flow of ions inside the probe tip. The effect was found to be minimal, in agreement with experimental data.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6756855
• Journal Information: Review of Scientific Instruments; (USA), Journal Name: Review of Scientific Instruments; (USA) Vol. 61:7; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
DATA ACQUISITION
ELECTROSTATIC PROBES
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
ION DENSITY
ION PROBES
ION TEMPERATURE
PERFORMANCE
PLASMA DIAGNOSTICS
PLASMA HEATING
PROBES
SPACE CHARGE