Abstract The response of single crystal methylammonium lead tribromide (MAPbBr 3 or MAPB) semiconductors to alpha particles at low voltage is presented. Through analysis of the preamplifier traces induced by 210Po alpha particles and collecting holes, we were able to determine the mobility–lifetime product, apparent mobility, trapping time constant, and the detrapping time constant. In addition, a quantitative study of the rate of positive polarization and device breakdown time at different applied voltages is presented. Finally, using a 239Pu/Be fast neutron source, we were able to demonstrate the response of MAPB to fast neutrons for the first time via benchmarking experiment with Monte Carlo simulations. [ABSTRACT FROM AUTHOR]