Abstract: A neutron spectrometer is provided to distinguish neutron capture events from other types of radiation in order to measure the energy associated with neutrons in a mixed radiation environment. The neutron spectrometer can include a neutron detector to capture neutrons and a controller to determine the energy associated with the captured neutrons. The neutron detector can include scintillating glass fibers embedded in a plastic scintillator. A photomultiplier tube can be positioned on each end of the detector to detect light pulses generated by both the scintillating glass fibers and the plastic scintillator. A controller can analyze the detected light pulses to determine when a neutron is captured and the energy associated with the neutron capture event.

Abstract: A silicon photomultiplier (SiPM) device is provided with a SiPM matrix fabricated on a substrate, a bias power supply connected to the SiPM matrix, and a compensation circuit coupled to the bias power supply. The bias power supply provides a bias voltage to the SiPM matrix. The compensation circuit can adjust the bias voltage applied to the SiPM matrix in response to temperature changes at the substrate. The compensation circuit includes a resistor fabricated on the substrate with the SiPM matrix. The resistor can have a resistance that varies in response to temperature changes at the substrate.

Abstract: A silicon photomultiplier (SiPM) device is provided with a SiPM matrix and a temperature compensation circuit fabricated on a substrate. The temperature compensation circuit can include a temperature sensor, a bias adjustment circuit and a current source. The current source can provide a current to the temperature sensor and the temperature sensor can provide a temperature dependent signal to the bias adjustment circuit. The bias adjustment circuit can adjust a bias voltage provided to the SiPM matrix in response to the signal from the temperature sensor in order to maintain a predefined overvoltage value at the SiPM matrix.