Simulations of energy deposition of electron cyclotron waves in a dipole-confined plasma based on ray trajectory

Abstract

The energy deposition of electron cyclotron waves in a dipole-confined plasma is investigated for the RT-1 device, specifically including the effects of high-energy electrons and the electron Bernstein wave (EBW) excitation and absorption. Simulations of wave trajectories with various injection locations and angles indicate that the energy deposition of ordinary mode (O-mode) and extraordinary modes (X-mode) is small in low-temperature plasmas. The high-energy electrons in the plasma increase the energy deposition of the X-mode but have little effect on the O-mode. Meanwhile, the energy deposition of the slow X-EBW conversion and O-X-EBW conversion to excite EBW is also discussed. The results show that the converted EBW in an over-dense plasma is easily obtained, but it may not always have efficient energy deposition. Finally, the possible mechanism for the plasma production and heating by using electron cyclotron waves is proposed.