Avalanche Breakdown
- An electron entering the conduction level of the dielectric at the cathode will move towards the anode under the effect of electric field. During the movement it gains energy and on collision it loses a part of energy. If mean free path is long energy gained due to motion is more than lost during collision. The processes continuous and finally may lead to formation of an electron avalanche similar to gain and breakdown place.
According to this strength depends on :
- Temperature and reduces with temperature
- Addition of foreign atoms to the crystal
- Dielectric strength decreases with increasing molecular volume.