Page 244 - MODERN ELECTROCHEMISTRY

180 CHAPTER 2

Fig. 2.70. (a) The field between the plates is normal
and the water dielectric is chemically stable. Its prop-
erty as an insulator depends on the concentration of
ions but it is highly resistive. (b) When the field
applied is sufficiently high, dielectric breakdown oc-
curs; the liquid no longer supports the field and the
charges flow away, forming “streamers.”

Fig. 2.71. Negative streamer
growth in a white naphthenic
mineral oil (Marcol 70). Gap:
1.27 cm; voltage step: 185 kV;
time in microseconds. (Re-
printed from R. E. Tobeozon,
The Liquid State and Its Elec-
trical Properties, Plenum
Press, New York, 1988.)