Speaker
Vladimir Alexandrovich Kornev
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.1070.pdf
Plasma heating and neutron production in the TUMAN-3M
V.A. Kornev, L.G. Askinazi, A.A. Belokurov, F.V. Chernyshev, S.V. Lebedev, A.D. Melnik,
A.S. Tukachinsky, N.A. Zhubr
Ioffe Institute, 194021, Saint-Petersburg, RF
Intense energetic neutral beams injection (NBI) is used for auxiliary plasma heating in
experiments on TUMAN-3M compact tokamak [1]. Recently, it was found that efficiency of
plasma heating and neutron production in the TUMAN-3M are hampered when NBI energy
exceeds some critical value ~14keV [2]. Among possible reasons for this degradation in
plasma heating and neutron production is plasma pollution by impurity influx, or neutral
beam attenuation in beam transmitting port [3]. This loss of beam power may results from the
process in which a fraction of the neutral beam is re-ionized and the tokamak magnetic field
deflects it to the port’s wall.
A series of experiments on TUMAN-3M was conducted with the injection of high-
energy atoms, aimed at clarifying the mechanism of saturation of neutron rate and ion
temperature with beam energy. A new transmission port was installed between the injector
and the tokamak, which, thanks to a larger cross-section, reduced beam-wall interaction, and a
risk of the beam attenuation. The efficiency of NBI was estimated through ion temperature,
fast particle spectra and neutron rate measurements. Observation of impurity lines from
tokamak plasma and D emission in the transmitting port was used to identify a possible
reason of plasma heating saturation at higher energy and power of the beam, and to clarify a
possible role of beam-wall interaction in the transmitting port. Numerical simulation of
neutron rate as function of beam power was carried out using the NUBEAM code.
The experiments presented in this paper were supported by Russian Science
Foundation (Project # 16-12-10285). Modeling of the neutron production was supported by
Ioffe Institute.
References:
[1] V.A. Kornev, L.G. Askinazi, M.I. Vildjunas et al., Techn. Phys. Lett., v 39 (2013), No 3, p 290
[2] V.A. Kornev, L.G. Askinazi, A.A. Belokurov et al., Nuclear Fusion, 57 (2017), 12, #126005, DOI:
http://dx.doi.org/10.1088/1741-4326/aa7d13
[3] A.C. Riviere, J. Sheffield, Nuclear Fusion, 15, 944 (1975)
