Conduction and Breakdown in Pure Liquids :
- When the fields are high (> 100 kV cm ) the current not only increase rapidly. but also undergo violent fluctuations which will die down after some time. Figure A.
- This is the condition nearer to breakdown. However if this figure is redrawn starting from very small currents, a current-electric field characteristics shown in Figure B is obtained.
- At very low fields, the current is due to the dissociation of ions.
- With intermediate fields the current reaches a saturation value and at high fields the current generated because of fluid-aided electron emission from the cathode gets multiplied in the liquid medium by a Townsend type of mechanism.
- The circuit multiplication also occurs from the electrons generated at the interfaces of liquid and impurities. The increase in current by these processes continues till breakdown occurs.