Fast switching ignitron

A recent application arose from switching a small, low-inductance capacitor bank having a system inductance of approximately 60 nH and a stored energy of 6 kJ at 15 kV. It is proposed to switch this system using three parallel connected ignitrons, which requires that the di /dt limit per ignitron be increased to 5×10¹⁰ A-s^-1. The authors describe the development and testing of a novel size `A´ ignitron (designed an NL 7708) that is capable of performing at the required switching speeds. Test results indicate that operation with a peak current of 88 kA and a maximum rate of current change of 4.55×10¹⁰ A-s^-1 (45.5 kA/μs) is well within the range of this ignitron