Hydrogen ion beam generated by a current-free double layer in a helicon plasma

Abstract

The role, played by a double layer (DL) in helicon produced expanding plasmas, in obtaining a supersonic ion beam of H2+ was analyzed. A retarding field energy analyzer (RFEA) positioned downstream of the DL helped in detecting the supersonic ion beam. The conditions for DL were affected by the electron dynamics. No change was observed in ion beam energy, relative to the lower peak at local plasma potential. The plasma conditions could be varied through the changes in plasma potential. The velocity and density ratio of hydrogen ion beam were found ∼2.1cs and 0.2 respectively. Show more