Experimental Investigation of a Low Frequency Instability

L o w f r e q u e n c y osc i l la t ions observed in a m o d i f i e d P I G d i s charge w e r e ident i f i ed as fluctuations o f the e l e c t r o n temperature . T h e s e osc i l la t i ons on ly o c c u r r e d u n d e r cer ta in c o n d i t i o n s ( l o w gas pressure , re lat ive ly h i g h m a g n e t i c field), w h e r e a s at h i g h pressure a n d l o w m a g n e t i c field s t rength the p l a s m a was r e m a r k a b l y s t a b l e ; this is w h y the d i s charge is r e f e r r e d to as a " q u i e s c e n t " P I G ( Q P I G ) d ischarge . T h i s p a p e r des c r ibes m e a s u r e m e n t s f o r o b t a i n i n g a de ta i l ed p i c t u r e o f the t w o m o d e s o f the d ischarge . A qual i tat ive e x p l a n a t i o n o f the p h e n o m e n a o b s e r v e d is o b t a i n e d u s i n g the e n e r g y b a l a n c e o f the e lec t ron gas.