Eur. Phys. J. D 56, 359-367 (2010)
https://doi.org/10.1140/epjd/e2009-00301-8

Fast wave heating in a mirror during plasma build-up

¹ Ångström laboratory, Uppsala University, 751 08 Uppsala, Sweden
² IPP NSC Kharkov Institute of Physics and Technology, Akademichna st. 1, 61108 Kharkiv, Ukraine
³ Budker Institute of Nuclear Physics, Lavrentiev Av. 11, 630090 Novosibirsk, Russia

Corresponding authors: moiseenk@ipp.kharkov.ua Olov.Agren@angstrom.uu.se

Received: 7 January 2009
Revised: 25 August 2009
Published online: 8 December 2009

Abstract

A heating method for partially ionized plasma has been described in reference [V.E. Moiseenko, Sov. J. Plasma Phys. 12, 427 (1986)]. It exploits the collisional damping of fast waves that is large owing to the high rate of charge exchange collisions. Since the time of heating is limited by the duration of neutral gas ionization, the heating needs to be strong enough to achieve a high final ion temperature. This heating method has been studied numerically in the framework of MHD-like (magneto-hydrodynamic) equations in inhomogeneous cylindrical plasma. The influences of the ratio of the mean free path of the neutral atoms to the plasma radius, the initial ion concentration, the characteristics of the interaction of the neutral atoms with the chamber wall and other parameters on the plasma heating dynamics are examined. A scenario for RF plasma heating in one central cell of the multi-mirror device GOL3 (Novosibirsk, Russia) is developed, in which the final ion temperature exceeds the ion oscillation energy in the RF field by one order of magnitude. The energy efficiency is high; only a small portion of the power is transferred by the neutral atoms to the chamber wall.