Development of a Helicon Plasma Source for the Measurement of He^* Component in a He⁰ Beam

Abstract

A high density plasma source using helicon discharge was designed for the measurement of the population ratio of the metastable state and ground state in a helium neutral beam. The required density of the plasma source was investigated in terms of the rate coefficient relevant to the beam-plasma interaction. The charge-exchange for the metastable state is a dominant process in a beam-energy range of 30-300 keV for the beam attenuation, promising the measurement of the metastable fraction in the helium neutral beam using this plasma source. The first plasma with the electron density of 3.4 × 10¹² cm^-3 and the electron temperature of 10 eV was successfully produced in argon gas.