Thermal neutron damage in DMILL bipolar transistors

Radiation damage caused by neutrons in DMILL npn bipolar transistors was measured. Transistors were exposed to neutrons with different fast-to-thermal flux ratios in the reactor in Ljubljana to fluences up to 5×1014 n/cm2. Degradation of transistor common emitter current gain was measured as the function of fluence. Large degradation caused by thermal neutrons (E<0.5 eV) was observed.