Abstract:
An electric discharge device has a conductive shell mounted in a non-conductive tube. A non-conductive collar can mount in the conductive shell. The collar includes an annular neck and an annular flange. The neck is encircled by a central annular groove located between a spaced pair of circumferential plateaus. The plateaus are radially dimensioned to fit in the conductive shell. The annular flange is coaxially affixed to and radially larger than the annular neck.