LOW-TEMPERATURE ION-SOURCE

A low temperature ion source has been developed to produce a plasma wi th a low ion temperature and a high plasma density by using a gas cont act technique. This ion source is a hybrid type consisting of modified plasma compression type cylindrical hollow cathode plasma source and the gas contact chamber with floating potential mounted on the head of the anode. The temperature of ions and the density in the produced ar gon plasma are gradually increased in order to compress it by the smal l canal of the floating electrode and the gas magnetic field. This pla sma flow goes into the gas contact chamber and mixes with the cold neu tral argon gas, resulting in the production of a low ion-temperature p lasma by ion-neutral collisions. The characteristics of the energy dis tribution of extracted ion beam (V(ex) = 500 V) were measured by an el ectrostatics analyzer and we determined both the half-value of the ene rgy spread of ion beam DELTAE and the mean ion temperature T(i) in the plasma flow. The mean electron temperature T(e) and plasma density n( e) were determined by means of a plane Langmuir probe. As a result, T( e) and DELTAE decrease from 4.1 to 2.5 eV and 13.3 to 8.3 eV, respecti vely, though n(e) is nearly constant at 3.0 X 10(10) cm-3.