Speaker
Petr Borisovich Shchegolev
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.1073.pdf
New powerful ion source for Globus-M2 spherical tokamak injector
P.B. Shchegolev1, A.Yu. Telnova1, V.B. Minaev1, N.N. Bakharev1, V.K. Gusev1,
E.O. Kiselev1, G.S. Kurskiev1, A.A. Panasenkov2, G.N. Tilinin2
1
Ioffe Institute, St. Petersburg, Russia
2
NRC “Kurchatov Institute,” Moscow, Russia
Neutral Beam Injection (NBI) is one of the main methods for additional heating of
tokamak plasma. In Globus-M2 spherical tokamak [1], toroidal magnetic field and plasma
current will more than double and plasma density will be significantly higher than in
Globus-M [2]. Thereby, in order to ensure the optimal depth of atomic beam penetration into
plasma before beam ionization, it is necessary to increase the energy of injected particles. For
this purpose, we developed a new three-electrode ion source with peripheral magnetic field
(ISPM-1M). While ISPM-1M retains the advantages of an arc discharge plasma emitter, the
design of its high-voltage insulator junction and slit ion-optical system is different from its
analogues ISPM-1 and ISPM-2 [3]. The main characteristics of ISPM-1M are as follows:
- maximum atomic beam power – 1MW;
- maximum accelerating voltage – 40kV;
- maximum ion beam current – 50A;
- emission surface area – 115cm2;
- number of electrode arrays – 4 pcs.;
- cathode heating voltage – 10.5V;
- cathode heating current – 1200A;
- discharge voltage – up to 70V;
- discharge current – up to 1300A.
This presentation details ISPM-1M structure, explains of ion-optical system geometry,
and discusses experimental results on discharge characteristics and parameters of arc
discharge plasma, as well as the emissivity of the new ion source and the dependence of the
optimum value of emission electrode current on accelerating voltage. Furthermore, the
presentation introduces calculations of fast particle losses in Globus-M2 plasmas during NBI
and predictive modeling results of heating and current drive created by the neutral beam for
Globus-M2 discharges.
References:
[1]. Minaev V.B., Gusev V.K., Sakharov N.V., et. al., Nuclear Fusion, 57 (2017) 066047
[2]. Gusev V.K., Golant V. E., Gusakov E. Z., et al., Technical Physics, 44 (1999) No. 9, 1054-1057
[3]. Gusev V.K., Dech A.V., Esipov L.A., et al., Technical Physics, 52 (2007) No. 9, 1127-1143
