Spectroscopic measurements of the excitation temperature and electron ensity of a Helium discharge lamp

Abstract

Optical emission spectroscopy was used to investigate the processes occurring in the plasma of a helium discharge lamp at two regions: capillary and electrode. The capillary region having a smaller cross-sectional area gives rise to higher intensities making it easy for spectroscopic measurements in laboratories. With elemental discharge lamps producing low-pressure plasmas, the Boltzmann plot method only gives the excitation temperature (T_exc) of the plasma. T_exc was found to be 3200K at the capillary region while the region near the electrode ranges from 1400K-1700K. The electron density at the capillary region was found to be 2.70x10¹⁴ cm^-3.