An integrated radiation detector having a pulse-mode operating photosensor optically coupled to a gamma sensing element and a neutron sensing element is disclosed. The detector includes pulse shape and processing electronics package that uses an analog to digital converter (ADC) and a charge to digital converter (QDC) to determine scintillation decay times and classify radiation interactions by radiation type. The pulse shape and processing electronics package determines a maximum gamma energy from the spectrum associated with gamma rays detected by the gamma sensing element to adaptively select a gamma threshold for the neutron sensing element. A light pulse attributed to the neutron sensing element is a valid neutron event when the amplitude of the light pulse is above the gamma threshold.