A New Toroidal Capacitive Discharge Plasma Vessel Design and Implementation for Plasma Studies

Abstract

A new toroidal capacitive discharge plasma (TCDP) system is designed and constructed for the first time to our knowledge. This device has been created for the exploration of plasma-material interactions including metal and semiconductor samples for different pressure rates. By using two materials, namely copper (Cu) and tungsten (W), initially, electrode couples have been tested for high-voltage DC excitations. The reactions of electron material to the low-pressure helium (He) have been observed. Then, Paschen’s curve exploration has been performed to find out the gas discharge threshold electrical potentials for various pressure (P) rates. The simulations of TCDP device have been performed in a particle in cell (PIC) analyzed 3D structure in the CST Studio medium for various excitation frequencies and toroidal/poloidal field values. It is observed that the breakdown voltage for He is U_B = 500 V. The DC excitation via the electrodes reveals that the torus-structured plasma gas media produces a stable torus-shaped media for plasma formation. Besides, toroidal and poloidal fields affect the plasma stabilization in the TCDP. Especially toroidal field coils in TCDP assist in keeping the plasma in the middle of the torus channel. According to the experiments, the poloidal fields increase the electric field strength in the angular direction and improve the electrical stability of the plasma between the electrodes.