On the use of relative line intensities of forbidden and allowed components of several HeI lines for electric field measurements

In this Letter we propose a method for electric field measurements based on intensity ratio of forbidden and allowed helium lines. HeI 402.6 nm, HeI 447.1 nm, and HeI 492.1 lines and their forbidden components are used for the measurement of electric field strength in the cathode region of the abnormal glow discharge in helium–hydrogen mixture. Electric filed strength was independently determined using polarization spectroscopy of HβHβ line and then compared with electric filed strength obtained from relative intensity of HeI forbidden and allowed lines.