Energy Loss and Microturbulence under Multipulse ECR Plasma Heating at the L-2M Stellarator
- Authors: Batanov G.M.1, Borzosekov V.D.1, Vasilkov D.G.1,2, Grebenshchikov S.E.1, Kolik L.V.1, Konchekov E.M.1, Letunov A.A.1, Petrov A.E.1, Stepakhin V.D.1, Kharchev N.K.1, Kharchevskii A.A.1
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Affiliations:
- Prokhorov General Physics Institute of the Russian Academy of Sciences
- Bauman Moscow State Technical University
- Issue: Vol 45, No 8 (2019)
- Pages: 732-740
- Section: Stellarators
- URL: https://journals.rcsi.science/1063-780X/article/view/187204
- DOI: https://doi.org/10.1134/S1063780X19080014
- ID: 187204
Cite item
Abstract
In experiments on multipulse on-axis electron cyclotron resonance heating (ECRH) of plasma by a series of microwave pulses at the L-2M stellarator, several phases of plasma energy loss were observed: the short stage of low-energy loss, the stage of rapid increase in energy loss, the quasi-steady stage, and the relaxation stage between the heating pulses. In the stage of rapid increase in energy loss, the energy loss power is two or more times higher than that in the relaxation stage at the same energy of the plasma column. Short-wavelength plasma density fluctuations were measured using both the ordinary and extraordinary microwave collective scattering technique. It is found that, in the quasi-steady stage, the amplitude of density fluctuations is much lower than that in the preceding heating stages. The fluctuation amplitude lowers just after the restructuring of the density profile and establishment of a steady-state hollow density profile due to the density pump-out effect. The amplitude of large-scale density fluctuations at the plasma periphery recorded by a Doppler reflectometer remains unchanged during the ECRH pulses and in the time intervals between them. However, when the stage of rapid increase in energy loss begins, the shape of the density fluctuation spectrum changes significantly. The initially narrow spectrum with one peak near the zero frequency broadens, the amplitude of the central peak decreases, and two additional peaks at frequencies of 0.7 and −0.7 MHz appear.
About the authors
G. M. Batanov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Author for correspondence.
Email: batanov@fpl.gpi.ru
Russian Federation, Moscow, 119991
V. D. Borzosekov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Author for correspondence.
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
D. G. Vasilkov
Prokhorov General Physics Institute of the Russian Academy of Sciences; Bauman Moscow State Technical University
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991; Moscow, 105005
S. E. Grebenshchikov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
L. V. Kolik
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
E. M. Konchekov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
A. A. Letunov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
A. E. Petrov
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
V. D. Stepakhin
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
N. K. Kharchev
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
A. A. Kharchevskii
Prokhorov General Physics Institute of the Russian Academy of Sciences
Email: borzosekov@fpl.gpi.ru
Russian Federation, Moscow, 119991
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