A neutron conversion foil for being used in a neutron detector includes a substrate having a first and second side. The substrate is covered at least on one of the first and second sides with a neutron conversion layer made of a neutron reactive material and being capable of capturing neutrons to thereafter emit light and/or charged particles. The neutron conversion foil is transparent to light such that light originating from the conversion of neutrons can pass through one or several of the neutron conversion foils and thereafter be collected and detected by a light sensing device.

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 neutron spectrum generator is disclosed herein including a neutron source, a scatterer positioned in a direct path between the neutron source and a neutron detector, and a material shell configured to have at least one non-uniform characteristic selected from the group consisting of a material, a thickness, a length, an angle, a layer, and combinations thereof to generate a specific spectrum at the neutron detector that is different than the spectrum of the neutron source. A related method includes measuring a first response generated by a first material shell of a neutron spectrum generator interacting with a neutron source, replacing the first material shell with a second material shell, measuring a second response generated by a second material shell of a neutron spectrum generator interacting with the neutron source, and determining a total fission response by determining a difference between the first response and the second response.

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.

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.

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 neutron detection apparatus includes a neutron detector and an analyzer. The neutron detector includes a plurality of neutron detector assemblies, where each of the neutron detector assemblies includes a plurality of neutron detection devices. The neutron detector also includes a moderating volume. The plurality of neutron detector assemblies are disposed within the moderating volume so as to form a three-dimensional array of neutron detection devices within the moderating volume. The analyzer is communicatively coupled to each of the neutron detection devices of the plurality of neutron detector assemblies. The analyzer configured to receive one or more measured response signals from each of the neutron detection devices, and perform one or more analysis procedures to determine one or more characteristics associated with the one or more neutron sources based at least on the received one or more measured response signals.

A remmeter includes two or more different-sized hydrogenous moderators, each incorporating a hydrogenous spectroscopic fast neutron detector and a thermal neutron detector to provide more accurate neutron dosimetry across a wide range of neutron energies (thermal neutrons to >15 MeV) in a form factor that is lighter than conventional remmeters. The remmeter utilizes the principle of spectral dosimetry, where the energy or energy distribution of the incident neutrons is first measured and then this energy information (along with the measured fluence) is used to establish the dosimetric quantity using the various fluence-to-dose conversion curves (e.g. H*(10) (ICRP(1997)), NCRP-38(1971)). Using the method of spectral dosimetry, the large variation in response in these curves as a function of neutron energy (especially over the region 1 keV to 1 MeV) is largely mitigated through the use of the energy and fluence information, and the appropriate fluence-to-dose conversion curve to calculate the dose.

A neutron conversion foil for being used in a neutron detector includes a substrate having a first and second side. The substrate is covered at least on one of the first and second sides with a neutron conversion layer made of a neutron reactive material and being capable of capturing neutrons to thereafter emit light and/or charged particles. The neutron conversion foil is transparent to light such that light originating from the conversion of neutrons can pass through one or several of the neutron conversion foils and thereafter be collected and detected by a light sensing device.

A neutron detection apparatus includes a neutron detector and an analyzer. The neutron detector includes a plurality of neutron detector assemblies, where each of the neutron detector assemblies includes a plurality of neutron detection devices. The neutron detector also includes a moderating volume. The plurality of neutron detector assemblies are disposed within the moderating volume so as to form a three-dimensional array of neutron detection devices within the moderating volume. The analyzer is communicatively coupled to each of the neutron detection devices of the plurality of neutron detector assemblies. The analyzer configured to receive one or more measured response signals from each of the neutron detection devices, and perform one or more analysis procedures to determine one or more characteristics associated with the one or more neutron sources based at least on the received one or more measured response signals.