Study on Stark broadening of low temperature He plasmas

Stark broadening is widely used to determine the electron density of the astrophysical plasmas and the atmospheric pressure plasmas. In low temperature plasmas Doppler broadening is larger than Stark broadening and the Stark broadening can be measured after removing Doppler broadening. In this research, the model for Stark broadening to determine the electron density was discussed in low temperature plasmas when Doppler broadening of plasma radiation was removed. The spectral line broadenings of van der Waals broadening, resonance broadening, natural broadening, and Stark broadening were calculated and compared with each other in low temperature He plasmas. As well the helicon plasma source of which electron density was higher than 10¹¹cm^-3 was constructed to investigate the helium Stark broadening. Stark broadening for 2¹S-4¹P was measured using the saturation absorption spectroscopy and the electron density could be determined by analyzing the Stark broadening.