Transient electron heat diffusivity obtained from trace impurity injection on TFTR
Open Access
- 1 March 1994
- journal article
- Published by IOP Publishing in Nuclear Fusion
- Vol. 34 (3) , 349-358
- https://doi.org/10.1088/0029-5515/34/3/i03
Abstract
A new method for obtaining a transient ('pulse') electron heat diffusivity (χep) in the radial region 0.38 < r/a < 0.56 in TFTR L mode discharges is presented. Small electron temperature perturbations were caused by single bursts of injected impurities which radiated and cooled the plasma edge. A case of iron injection by laser ablation was found to be more definitive than a supporting helium gas puff case. In this new 'cold pulse' method, the authors concentrate on modelling just the electron temperature perturbations, tracked with electron cyclotron emission diagnostics, and on being able to justify separation of the perturbations in space and time from the cooling source. This χep is obtained for these two cases to be χep = (6.0 m2/s ± 35%) ~ 4χe (power balance), which is consistent with but more definitive than results from other studies that are more susceptible to ambiguities in the source profileKeywords
This publication has 24 references indexed in Scilit:
- Helium, iron, and electron particle transport and energy transport studies on the Tokamak Fusion Test ReactorPhysics of Fluids B: Plasma Physics, 1993
- Resolving apparent differences between heat and density pulse propagation in JET and TEXTNuclear Fusion, 1991
- Interpretation of heat and density pulse measurements in JET in terms of coupled transportNuclear Fusion, 1991
- Observation of temperature-dependent transport in the TFTR tokamakPhysical Review Letters, 1991
- Dependence of heat pulse propagation on transport mechanisms: Consequences of nonconstant transport coefficientsPhysics of Fluids, 1988
- Heat pulse propagation studies in TFTRNuclear Fusion, 1986
- Numerical Studies of Impurities in Fusion PlasmasNuclear Technology - Fusion, 1983
- On measuring the electron heat diffusion coefficient in atokamak from sawtooth oscillation observationsNuclear Fusion, 1979
- Experimental Measurement of Electron Heat Diffusivity in a TokamakPhysical Review Letters, 1977
- System for rapid injection of metal atoms into plasmasReview of Scientific Instruments, 1975