Design of a high particle flux hydrogen helicon plasma source for used in plasma materials interaction studies

Existing linear plasma materials interaction (PMI) facilities all use plasma sources with internal electrodes. An rf‐based helicon source is of interest because high plasma densities can be generated with no internal electrodes, allowing true steady state operation with minimal impurity generation. Work has begun at Oak Ridge National Laboratory (ORNL) to develop a large (15 cm) diameter helicon source producing hydrogen plasmas with parameters suitable for use in a linear PMI device: ne⩾1019 m−3, Te = 4–10 eV, particle flux Γp>1023m−3 s−1, and magnetic field strength |B| up to 1 T in the source region. The device, whose design is based on a previous hydrogen helicon source operated at ORNL[1], will operate at rf frequencies in the range 10–26 MHz, and power levels up to ∼100 kW. Limitations in cooling will prevent operation for pulses longer than several seconds, but a major goal will be the measurement of power deposition on device structures so that a later steady state version can be designed. The dev...