Title :
Role of electron impact in ac electrical tree initiation
Author :
Shimizu, N. ; Sato, H.
Author_Institution :
Nagoya Univ., Japan
Abstract :
Electrons injected from electrode are accelerated in polymer free volume. These hot electrons bombard polymer chain. Electron impact excites polymer molecules and causes electroluminescence. If electron energy is enough high, polymer chain is broken and free radicals are produced. Kind of gas in free volume has a large effect on ac tree initiation. O2 reacts with free radical and causes autoxidation which proceeds very fast to form cavity. For He or Ar, hot electrons excite them to metastable level. Metastable atoms transfer the energy to polymer molecules and breaks polymer bond to create cavity in short time
Keywords :
electroluminescence; free radicals; hot carriers; organic insulating materials; polymers; trees (electrical); AC electrical tree; Ar; He; O2; autoxidation; bond scission; electroluminescence; electron impact; free radical; free volume; gas cavity; hot electron injection; metastable atom; molecular excitation; polymer chain; Acceleration; Argon; Atomic measurements; Bonding; Electrodes; Electroluminescence; Electrons; Helium; Metastasis; Polymers;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1997., Proceedings of the 5th International Conference on
Conference_Location :
Seoul
Print_ISBN :
0-7803-2651-2
DOI :
10.1109/ICPADM.1997.617624
