Comparison of two types of antennas for plasma heating

Abstract

The ability of a quadrupole coil, an antenna, of new design for the production of high-energy protons in a plasma has been compared experimentally with that of a conventional wraparound coil. The energies of the protons in the escape cone of a magnetic bottle were measured by a Faraday cup. The antennas were placed alternately midway between the two solenoids and operated in resonance under similar conditions. Proton energies of 380 eV were attained with the new quadrupole coil, a value more than twice that obtained by the wraparound coil. Thus, the new coil is judged superior for the purpose of ion cyclotron resonance heating.