Surface Plasma Sources with Helicon Plasma Generators

Abstract

A Surface Plasma Source (SPS) with plasma generation by a saddle type antenna is discussed. The following features of the helicon discharge with a saddle type antenna in magnetic field are identified: efficient plasma generation in resonant condition, low gas density, strong separation of plasma from the wall, possibility to control plasma flux distribution by magnetic field configuration. Applications of saddle type antenna in SPS for accelerators for Homeland Security and for Neutral Beam Injectors (NBI) are considered.

H- Ion Sources for High Intensity Proton Drivers

“…Features of this saddle type of helicon discharge system include [5]: high efficiency of plasma generation using a resonance in a weak magnetic field, low gas density (1 to 5 mTorr), strong separation of plasma from the chamber wall, low flux of plasma particles to the discharge chamber wall, and flexible control of the plasma flux distribution by magnetic field adjustment. Resonant plasma generation has been observed in previous investigations of RF ion sources with an RF field with frequency of ~10 MHz and magnetic fields ~100 G. In an RF field with frequency f, the dependence of the plasma density on magnetic field has a resonant peak at a magnetic field B res║ = 4 B c for a magnetic field parallel to the RF coil axis, and at B res┴ ~ 2 B c for magnetic field perpendicular RF coil axis.…”

Negative ion radio frequency surface plasma source with solenoidal magnetic field

“…Efficiency of plasma generation in a Radio Frequency (RF) ion source can be increased by application of a solenoidal magnetic field [1][2][3][4][5][6][7][8][9]. The specific efficiency of positive ion generation was improved by the solenoidal magnetic field, from 5 mA/cm 2 kW to 200 mA/cm 2 kW [8,9].…”