irh9230.pdf datasheet:

Provisional Data Sheet No. PD-9.1391IRH9230AVALANCHE ENERGY AND dv/dt RATEDHEXFET TRANSISTORP-CHANNELRAD HARDProduct Summary-200 Volt, 0.8 RAD HARD HEXFET, International Rectifiers P-Channel RAD HARD technologyPart Number BVDSS RDS(on) IDHEXFETs demonstrate excellent threshold voltage stabilityand breakdown voltage stability at total radiation doses asIRH9230 -200V 0.8 -6.5Ahigh as 105 Rads (Si). Under identical pre- and post-radiationtest conditions, International Rectifiers P-Channel RADHARD HEXFETs retain identical electrical specifications upFeatures:to 1 x 105 Rads (Si) total dose. No compensation in gate Radiation Hardened up to 1 x 105 Rads (Si)drive circuitry is required. These devices are also capable ofsurviving transient ionization pulses as high as 1 x 1012 Rads Single Event Burnout (SEB) Hardened