Analytical treatment for establishing load-cycle ratings of ignitrons

THE ignitron offers unique possibilities as a control element for high instantaneous alternating demand currents. The demand current is limited only by the capacity of the ionized vapor to conduct the current from the mercury pool to the anode and by probability of arc back, which increases as the peak current conducted by the tube increases. The design of ignitron tubes is a compromise between these two factors. Design for low arc-back rate usually results in anode baffles and shields which tend to increase the deionizing properties of the tube and thus decrease the peak current-carrying capacity.