Abnormality of Electric probe Characteristics due to nagative ions

초록

Although the electron temperature measured by the electric probe seems to increase due to negative ions over the some portion of negative density (> 20% of electron density) [1-3], there is no clear physical reason for this electron heating. It may be caused by the abnormal behaviour of electric probe characteristics on collection negative particles in the high ratios of negative ion to electron density. To study further this phenomenon, probe measurement has been done in the multi-dipole plasma device with Ar and O2 mixture plasma along with previous measurement in LaB6 DC plasma [1]. The negative ion density is also measured by the laser-photo detachment method. A new method to determine the proper electron temperature will be given in terms of gas pressure for the generation of negative ions.