Dependence on the Operation Frequency of Negative Glow

Abstract

Measuring the Ne-Hg negative glow lamp (having no positive column), authors found the efficiency decreased as frequency increased. Authors measured the characteristics of this plasma to grasp the reason for it. There are two groups of electrons in this plasma. One group consists of first electrons whose peak energy at high frequency (HF) operation is higher than at low frequency (LF). The other consists of second electrons whose energy at HF operation is lower than at LF. There was the period without first electrons at HF operation. From these results, authors attribute the reason for the decreasing efficiency to the followings. (1) The period of the energy transfer from first electrons to second electron at HF operation is shorter than at LF, because there is the period without first electrons at HF operation. (2) lonization loss at HF operation is higher than at LF, because of the higher peak energy of first electrons. Lastly authors checked the negative glow performance of 2 lamps, which were Ne-Hg lamp and Ar-Hg lamp with positive column, to compare with that of Ne-Hg lamp without positive column, and confirmed that there are no difference among the negative glow performance of these 3 lamps. It is considered from these measurement that the peak of cathode fall voltage at HF operation is higherthan at LF, in spite of the cathode fall voltage is lower at HF in r.m.s.