Plasma parameters in a multidipole plasma system

Plasma potential and electron number densities and electron temperatures un der bi-Maxwellian approximation for electron distribution function of the m ultidipole argon plasma source system were measured for a gas pressure rang ing between 10(-4) and 10(-3) mbar and an anode-cathode voltage ranging bet ween 40 and 120 V but a constant discharge current intensity. The first gro up, as ultimate or cold electrons and main electron plasma population, resu lts by trapping of the slow electrons produced by ionisation process due to primary-neutral collisions. The trapping process is produced by potential well due to positive plasma potential with respect to the anode so that ele ctron temperature of the ultimate electrons does not depend on both the gas pressure and discharge voltage. The second group, as secondary or hob elec trons, results as degrading process of the primaries and their number densi ty increases while their temperature decreases with the increase of both th e gas pressure and discharge voltage.