2020 年 18 巻 6 号 p. 317-322
A theoretical and numerical study has been conducted on an electrodeless thruster which uses a traveling magnetic field for effective thrust generation. The physics behind the thrust generation mechanism was studied theoretically, and the theory was validated by 1D electrostatic particle-in-cell simulations. The thrust generation was found to be due to the formation of a Double Layer (DL). The magnetic pulse pushes the electrons in the magnetic front forming a small charge separation. The localized electric fields arising due to this separation causes significant acceleration of the ions, and the electrons in opposite directions. However, this leads to further charge separation, deepening the potential well across leading to the formation of a DL which in turn generates mono-energetic ion beams. The energy required for sustaining the DL is derived from the trapped electrons in the leading front of the DL. The theory predicts a drop in the temperature of trapped electrons. This temperature decrease is confirmed by the electron thermal energy distribution obtained from the simulation.