The study on anion drift characteristics of typical gas composition in GIS

under lower E/N

by ion mobility tube with pulse electron injection

has been finished.The objects of study include O

2

SO

2

、SOF

2

、SO

2

F

2

and SF

6

.In the E/N range of 0.264～1.168 Td

the results show:Because the loss of charge is avoided by ion mobility tube with pulse electron injection

the signal intensity of anion current is enhanced greatly.The drift time of negative ion of objects have good linear

relation with electric field.The longer the drift distance

the larger the rate of change of drift time.The influence of speed instability during initial acceleration period can be eliminated by deviation calculation of drift distance and drift time.With the increase of drift electric field

the ion mobility of negative ion decrease at first

and then stable at a fixed value which is not changed with drift electric field.Under lower electric field

anion thermal motion has larger effect on ion mobility.