Tesla coil IRFP460

Friends! I did some experiments with a Tesla transistor coil on an IRFP460 field-effect transistor. This is the simplest circuit that creates electrical discharges up to 27 cm long at a voltage of 220 V. However, periodically the field-effect transistor will burn out, for this I additionally installed a thyristor interrupter, with which you can adjust the frequency. There is no thyristor breaker in The circuit you see. If necessary, I can make a reference to the interrupter. The coil has a wire diameter of