Abstract
Several polymeric insulator materials commonly used as sidewall insulators in electromagnetic accelerators are subjected to repetitive (from ~0.1 to 1 discharges per second), high current (from ~100 to 300 kA peak or ~100 to 300 kA/cm), transient (~20 μs pulse width) surface discharges. The insulator materials tested include the thermosetting polymers G-9, G-10, and G-ll (i.e., fiberglass reinforced melamine and epoxy) and the thermoplastic polymers Lexan™ (i.e., polycarbonate) and Delrin” (i.e., polyacetyl). Empirical scaling relationships are given that relate the total amount of insulator and electrode (i.e., molybdenum) mass erosion versus the total amount of arc energy transferred. Scaling relationships are also given that relate the “lifetime” of the given polymer as a function of the initial discharge current The “lifetime” of an insulator material is defined as the number of discharges required to reduce the initial surface holdoff voltage to its half-power level (i.e., Vinitial/2) for three consecutive discharges and is a useful parameter when specifying insulator materials to be used in high power switching devices.
Original language | English |
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Pages (from-to) | 1143-1147 |
Number of pages | 5 |
Journal | IEEE Transactions on Magnetics |
Volume | 29 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1993 |