Axial Electric Field of He–Ne and He–Ar Gas Mixture Positive Column Plasmas in a Capillary Discharge Tube

The axial electric field of a positive column in a 0.8 mm-I.D. capillary discharge tube was measured for He–Ne and He–Ar gas mixtures at gas pressures from 0.1 to 10 Torr and discharge currents from 10 to 30 mA. The results show no significant percentage neon gas mixture effect on the axial electric field up to 10% neon in the He–Ne mixture. However, if we mix more than 1% of argon in helium, the axial electric field is observed to reduce significantly. The results also show that the axial electric field decreases with increasing percentages of neon and argon in He mixture.