Reticulant doped semiconductive epoxies and plastics for high voltage applications

Various techniques of doping epoxies and plastics for use in solving high-voltage problems associated with particle accelerators and high-voltage power supplies have been investigated. These studies have centered on two categories of dopants: antistatic additives and the organic charge-transfer salts tetrathiofulvalene (TF) and tetracyanoquinodimethane (TCNQ). A small percentage (<10 wt.%) of these dopants added to otherwise insulating material produces semiconducting bulk resistivities on the order of 10/sup 6/ to 10/sup 10 / Omega -cm. Such semiconducting material could form the basis for easily produced, rugged, high-voltage load resistors, high-voltage grading films and coatings for use with high voltage platforms, terminals, acceleration columns, and power supply testing. Specific goals were consistent reproducibility, easily controlled process parameters for resistance adjustment, wide resistance range, and a low-to-modest processing hardware investment. Conductive materials with a wide range of resistivity (10/sup 3/-10/sup 10 / Omega -cm) have been easily fabricated.<>