Cold plasma generation by optical field ionization with hydrogen and helium gas mixture

To generate plasmas with low average electron energy, the optical field ionized plasmas with helium and hydrogen gas mixture was studied. To measure the average electron energy, the line intensity ratio was measured experimentally and calculated using an atomic kinetic model. The measured line intensity ratio indicates that the average electron energy is 3 eV for the case of 5 % helium and 95 % hydrogen gas mixture.