Beam Ion Loss Due to the Charge Exchange Process in the Open Field Region of a Field-Reversed Configuration

Abstract

Beam ion loss due to the charge exchange with deuterium atoms in the open field region of a field-reversed configuration (FRC) is investigated by tracing its orbit. The beam ion is tangentially injected as neutral beams (NBs) into the FRC. The ionization process is reproduced by the Monte-Carlo method. Almost all of the 15 keV beam ions injected toward the field null are found to be confined in the case with an external magnetic field of 0.2 T. It is found that about 90% of the NB injection power is transferred to the plasma when the neutral atom density in the open field region is lower than 1017 m-3.