Antenna analysis in magnetized plasma via particle-in-cell simulation Original Research Article

We for the first time applied electromagnetic Particle-In-Cell (PIC) computer simulations to analyze the antenna characteristics in magnetized plasma. In a three-dimensional simulation space, we placed a dipole antenna which is a conducting current line in a magnetized plasma. By providing a Gaussian pulse as an input power to the center of the antenna and observing the current induced at the power feeding point, we obtain the input impedance of the antenna as a function of frequency. We particularly examined the electron kinetic effects on the antenna impedance such as electron temperature and electron evacuated region (ion sheath) formed around the antenna. It is confirmed that the most obvious resonance point is the local Upper Hybrid Resonance frequency. As the electron temperature increases, the resonance frequency also increases in accordance with the modification of dispersion relation for the UHR branch. We also examined the antenna impedance variation by changing the size of the electron evacuated region or ion sheath created around the antenna. We could confirm that the antenna resonance near the local UHR frequency is sharp for the small sheath while the profiles of the impedance approach to those of vacuum case as the sheath becomes large. The resonance frequency also decreases because the plasma density also decreases in the vicinity of the antenna.