A laser photopeak location system comprises a gamma-ray spectrometer and a processor. The processor computes a plurality of correlation coefficients based on a comparison of a pulse-height spectrum of the gamma-ray spectrometer with an array of values. The processor locates one or more photopeaks of the pulse-height spectrum based on at least one of the plurality of correlation coefficients. Additional apparatus, methods, and systems are disclosed.

A method and apparatus are provided for nonlinear energy correction of a gamma-ray detector using a calibration spectrum acquired from the background radiation of lutetium isotope 176 (Lu-176) present in scintillators in the gamma-ray detector. Further, by periodically acquiring Lu-176 spectra using the background radiation from the scintillators, the nonlinear energy correction can be monitored to detect when changes in the gamma-ray detector cause the detector to go out of calibration, and then use a newly acquired Lu-176 spectrum to update the calibration of the nonlinear energy correction as needed. The detector calibration is performed by comparing a reference histogram to a calibration histogram generated using the nonlinear energy correction, and adjusting the parameters of the nonlinear energy correction until the two histograms match. Alternatively, the detector calibration is performed by comparing reference and calibration values for specific spectral features, rather than for the whole Lu-176 spectrum.

Methods and apparatus for calibrating radioactive sources are described. An array of scintillation detectors form a receptacle within which a sample or sample container can be retained by a holder. The scintillation detectors are coupled via light transducers such as photomultiplier tubes (PMTs) to independent electronic counters. Coincidence processing of time-tagged events yields a correlated event rate. One or more corrections can be applied as needed, for background counts, deadtime, or random coincidences. Voltage tuning of PMTs yields improved reproducibility. Variations are disclosed. 1% accuracy has been demonstrated over a range of 10 kBq-3 MBq, covering a gap in the capabilities of conventional technology.

In a method and control unit for activating an X-ray detector, having an X-ray sensitive sensor layer and an arrangement of pixel electrodes connected at the back to the sensor layer, an individually adjusted depletion voltage is applied to each of the pixel electrodes. The value of the depletion voltages applied to different pixel electrodes is chosen to be different such that the effective pixel sizes respectively associated with the pixel electrodes are aligned with each other.

In a method and control unit for activating an X-ray detector, having an X-ray sensitive sensor layer and an arrangement of pixel electrodes connected at the back to the sensor layer, an individually adjusted depletion voltage is applied to each of the pixel electrodes. The value of the depletion voltages applied to different pixel electrodes is chosen to be different such that the effective pixel sizes respectively associated with the pixel electrodes are aligned with each other.

A spectroscopic gamma and neutron detecting device includes a scintillation detector that detects gamma and thermal neutron radiation, the scintillation detector including signal detection and amplification electronics, and a stabilization module configured to measure a pulse height spectrum of neutron radiation, determine a thermal neutron peak position in the neutron pulse height spectrum originating from cosmic ray background radiation, monitor the thermal neutron peak position in the neutron pulse height spectrum during operation of the spectroscopic gamma and neutron detecting device, and adjust the signal detection and amplification electronics based on the thermal neutron peak position in the neutron pulse height spectrum, thereby stabilizing the spectroscopic gamma and neutron detecting device.

A radiation imaging apparatus includes a pixel unit including a plurality of pixels and configured to generate image data according to received irradiation of radiation from a radiation generation apparatus, and a control unit configured to acquire irradiation information regarding a radiation irradiation area or an irradiation position of the pixel unit, calculate brightness information of each of successive pieces of image data provided by the pixel unit based on the image data and the irradiation information, generate irradiation condition information of the radiation generation apparatus based on the brightness information, and transmit the irradiation condition information to the radiation generation apparatus. The control unit recalculates the brightness information when a fluctuation of the brightness information exceeds a threshold value. The control unit does not transmit irradiation condition information based on the recalculated brightness information to the radiation generation apparatus until a predetermined period of time elapses since the recalculation.

A method for controlling the gain and zero of a multiple pixel photon counter device, and light-measuring system implementing said method. Signals provided by the device are acquired for predefined periods, until a predefined total measurement time is reached, an amplitude histogram is formed from the acquired signals, the positions of two consecutive peaks, measurable on the histogram, are determined, an error signal is produced, which is equal to the deviation between both peaks and, by means of the same, the voltage supplying the device is regulated, so as to keep the deviation equal to a predefined set point.

A method for controlling the gain and zero of a multiple pixel photon counter device, and light-measuring system implementing said method. Signals provided by the device are acquired for predefined periods, until a predefined total measurement time is reached, an amplitude histogram is formed from the acquired signals, the positions of two consecutive peaks, measurable on the histogram, are determined, an error signal is produced, which is equal to the deviation between both peaks and, by means of the same, the voltage supplying the device is regulated, so as to keep the deviation equal to a predefined set point.

A gamma-ray spectrometer calibration system comprises a light guide, a photomultiplier tube, a laser, and analysis electronics. The light guide is optically coupled to the scintillation crystal, the laser and the photomultiplier tube, such that the laser can provide reference signals to the photomultiplier tube. In some embodiments, one or more temperature sensors are provided, such that the analysis electronics determine initial settings and adjust the initial settings based on the temperatures measured by the temperature sensors. Additional apparatus, methods, and systems are disclosed.