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.

Techniques are disclosed for systems and methods to detect radiation accurately, and particularly in a highly radioactive environment. A system includes a detector module for a radiation detector and a parallel signal analyzer configured to receive radiation detection event signals from the detector module and provide a spectroscopy output and a dose rate output. The parallel signal analyzer may be configured to analyze the radiation detection event signals in parallel in first and second analysis channels according to respective first and second measurement times and determine the spectroscopy output and the dose rate output based on radiation detection event energies determined according to the respective first and second measurement times.

A photomultiplier simultaneously detects gamma and neutron radiation. The detector includes an external scintillator sensitive to neutron radiation, which is optically coupled to an internal scintillator sensitive to gamma radiation; a solid-state silicon photomultiplier capable of simultaneously registering optical signals from both the external scintillator and internal scintillator, and of transforming the signals into electrical pulses; and a signal processing unit. The external scintillator is a lamination/paint or film. The entire surface of the internal scintillator is covered, except for an area that is adjacent to the input window of the solid-state silicon photomultiplier. The signal processor includes a preamplifier, a spectrometric amplifier, and a pulse shape analyzer. The photomultiplier has improved neutron sensitivity due to the external scintillator covering almost the entire edge surface of the internal scintillator. A solid-state silicon photomultiplier reduces size and power consumption, and improves resistance to mechanical and magnetic impacts.

A gamma-ray spectrum classification apparatus, comprising circuitry configured: to provide a denoising autoencoder to receive gamma-ray spectrum data representing a gamma-ray spectrum of a material to be classified and to determine feature data indicative of one or more features representative of the gamma-ray spectrum data; and to provide a classification neural network to receive the feature data and to classify the material to be classified as one of a plurality of predetermined classifications using the feature data.

A method of measurement of both gamma radiation and neutrons with energies above 500 keV is provided utilizing a scintillation crystal. The method includes allowing gamma quanta and neutrons to interact with the scintillation crystal, collecting light emitted by the scintillation crystal and letting that light interact with a photo detector, and amplifying the signal output. The method then digitizes the amplifier output signal, determines a charge collection time for each interaction measured, determining light decay times, separating signals with distinct decay times, determining a total charge collected from signals with the distinct decay times, and sorting charge signals in a spectrum. The method then counts signals with a second decay time and determines a count rate.

A photomultiplier simultaneously detects gamma and neutron radiation. The detector includes an external scintillator sensitive to neutron radiation, which is optically coupled to an internal scintillator sensitive to gamma radiation; a solid-state silicon photomultiplier capable of simultaneously registering optical signals from both the external scintillator and internal scintillator, and of transforming the signals into electrical pulses; and a signal processing unit. The external scintillator is a lamination/paint or film. The entire surface of the internal scintillator is covered, except for an area that is adjacent to the input window of the solid-state silicon photomultiplier. The signal processor includes a preamplifier, a spectrometric amplifier, and a pulse shape analyzer. The photomultiplier has improved neutron sensitivity due to the external scintillator covering almost the entire edge surface of the internal scintillator. A solid-state silicon photomultiplier reduces size and power consumption, and improves resistance to mechanical and magnetic impacts.

The invention is a gamma ray detector that locates a source, both horizontally and vertically. The detector comprises a tubular shield surrounded by scintillator panels. Gammas incident from one side can fully strike the scintillator facing the source, but are blocked from reaching the scintillators on the opposite side of the shield. The scintillator counting rates thus indicate the lateral direction of the source. By iteratively rotating toward the highest-counting scintillator, the detector converges to the source. An additional, central detector can be mounted within the tubular shield. When analyzed with the outer scintillators, the central detector determines the overall angular separation between the source and the detector axis, thereby locating the source in two dimensions automatically. The invention enables rapid detection and precise localization of clandestine nuclear and radiological weapons, despite shielding and clutter obfuscation, while quickly passing clean loads.

A radiation detection system and a method for a parallel detection of gamma-rays and neutrons are provided, comprising a gamma-ray detector comprising a scintillator crystal comprising .sup.127I, a digitizer to generate digitized time series and an analyzer, characterized in that the analyzer is adapted to identify a primary signal component, a first delayed signal component and a second delayed signal component in the digitized time series. The first and second delayed signal components, respectively, correspond to an energy deposition of about 30 keV and about 138 keV, and follow the primary and first delayed signal components in time. The analyzer is further adapted to count the number of digitized time series comprising at least the first and the second delayed signal components as neutron events, thereby providing a measure for a neutron flux the scintillator crystal is exposed to.

A phoswich neutron detection system with at least two scintillators, each having differing pulse shape characteristics, and an optical detector, and neutron spectroscopy capability.

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.