Plasma diagnostic in a compact IEC-based nuclear fusion device

Abstract

In this paper, the plasma parameters in the Iranian-Inertial Electrostatic Confinement Fusion (IR-IECF) device are measured using a Langmuir probe system. For this purpose, different parts of the Langmuir probe and necessary equipment are designed and constructed. The IR-IECF device, a compact IEC-based fusion device for nuclear fusion researches operating in pulsed or continuous mode, consists of two concentric or coaxial electrodes that the central one is negatively high voltage-biased and the outward electrode is grounded. In this configuration, the strong electric field between electrodes leads to ionization the filling gas resulting in hot and dense plasma formation in the center of the device. By applying voltage to the probe electrode being in direct contact with the plasma formed in the IR-IECF device, the current drawn from the probe is measured. Henceforth, by interpreting the obtained current-voltage (I-V) characteristic curve, the plasma parameters are determined for different conditions of discharge voltage and current. Moreover, by moving the probe between the electrodes, the plasma parameters at different distances from the IR-IECF device center are measured.