Enhancement of electron temperature in a laser-induced plasma using a radio-frequency electric field

An experimental study of the enhancement of the electron temperature of a laser-induced plasma by use of radio-frequency dielectric heating has been carried out. A radio-frequency electric field of 140 MHz is used to heat the plasma produced by multistep resonant photoinization. It is clearly observed that the electron temperature increases from 0.3 to 1.0 eV when a radio-frequency input power of 1.0 W is applied. Also, applying heating induces a plasma oscillation. This is due to the generation of ion waves in the plasma, and therefore, means that the enhanced electron temperature is higher than the ion temperature. It is expected that this method will improve the efficiency for extracting ions rapidly from a laser-induced plasma in atomic vapor laser isotope separation. (C) 2000 American Institute of Physics. [S1070-664X(00)05302-7].