Measurements of radial profiles of ion cyclotron resonance heating on the tandem mirror experiment

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6049091

Falabella, S

A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawrence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). This analyzer indicates an increase in ion temperature from {approx}20 eV before ICRH to {approx}150 eV during ICRH, with {approx}60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial integral of n{sub i}T{sub i} as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma potential is seen to vary from axially peaked, to nearly flat, as the plasma conditions varied over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U.

• Research Organization: California Univ., Davis, CA (USA)
• OSTI ID: 6049091
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700102 -- Fusion Energy-- Plasma Research-- Diagnostics
A CODES
COMPARATIVE EVALUATIONS
COMPUTER CODES
ELECTRIC POTENTIAL
G CODES
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
INTERFEROMETRY
ION DENSITY
ION TEMPERATURE
LAWRENCE LIVERMORE LABORATORY
MAGNETIC MIRRORS
MEASURING INSTRUMENTS
MODIFICATIONS
NATIONAL ORGANIZATIONS
OPEN PLASMA DEVICES
PLASMA DIAGNOSTICS
PLASMA HEATING
PLASMA POTENTIAL
POWER
PROBES
TANDEM MIRRORS
THERMONUCLEAR DEVICES
TMX DEVICES
US AEC
US DOE
US ERDA
US ORGANIZATIONS