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Results for “Neutron Detection”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Demonstration of neutron detection utilizing open cell foam and noble gas scintillation

We present results demonstrating neutron detection via a closely spaced converter structure coupled to low pressure noble gas scintillation instrumented by a single photo-multiplier tube (PMT). The converter is dispersed throughout the gas volume using a reticulated vitreous carbon foam coated with boron carbide (B{sub 4}C). A calibrated cold neutron beam is used to measure the neutron detection properties, using a thin film of enriched {sup 10}B as a reference standard. Monte Carlo computations of the ion energy deposition are discussed, including treatment of the foam random network. Results from this study indicate that the foam shadows a significant portion of the scintillation light from the PMT. The high scintillation yield of Xe appears to overcome the light loss, facilitating neutron detection and presenting interesting opportunities for neutron detector design.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Neutron detection performance of gallium nitride based semiconductors

Neutron detection is crucial for particle physics experiments, nuclear power, space and international security. Solid state neutron detectors are of great interest due to their superior mechanical robustness, smaller size and lower voltage operation compared to gas detectors. Gallium nitride (GaN), a mature wide bandgap optoelectronic and electronic semiconductor, is attracting research interest for neutron detection due to its radiation hardness and thermal stability. This work investigated thermal neutron scintillation detectors composed of GaN thin films with and without conversion layers or rare-earth doping. Intrinsic GaN-based neutron scintillators are demonstrated via the intrinsic 14 N(n, p) reaction, which has a small thermal neutron cross-section at low neutron energies, but is comparable to other reactions at high neutron energies (>1 MeV). Gamma discrimination is shown to be possible with pulse-height in intrinsic GaN-based scintillation detectors. Additionally, GaN-based scintillation detector with a 6 LiF neutron conversion layer and Gd-doped GaN detector are compared with intrinsic GaN detectors. These results indicate GaN scintillator is a suitable candidate neutron detector in high-flux applications.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Evaluation of MSNDs for Fast-Neutron Detection and the TREAT Hodoscope

The need for next-generation, accident-tolerant fuels has generated significant interest in the restart of domestic fuels testing at the Transient Reactor Test (TREAT) facility. A key feature of the TREAT reactor core is an open, horizontal channel that allows line-of-sight viewing of test specimens using various instrumentation during steady-state and transient operation. This instrumentation includes the hodoscope, which consists of over 300 steel-collimated channels coupled to Hornyak buttons (and other detectors) for detection of fast neutrons emitted from fission of the test specimen. Posterior analysis can be used to reconstruct fuel motion and other properties from the collimated channel signals. A large-scale effort is underway to develop next generation instrumentation for transient testing at TREAT (and, potentially, other facilities). Work at KSU specifically aims to provide improved detection systems for hodoscope applications. It was initially proposed to adapt KSU-developed Microstructured Semiconductor Neutron Detectors (MSNDs) for use as fast-neutron detectors. The current generation of MSNDs is designed for thermal-neutron detection based on {sup 6}Li and can achieve intrinsic efficiencies nearing 30% owing to the large (n, t) cross section of {sup 6}Li and clever optimization of the geometry. In order to evaluate MSNDs for fast-neutron detection, two approaches were considered: (1) use of a hydrogenous material to thermalize neutrons to exploit the intrinsic efficiencies of current MSNDs, and (2) substitution of a fast-sensitive reactant for {sup 6}Li. The former approach is attractive because it makes use of proven, off-the-shelf technology and leads to reasonable time resolution and efficiency. Unfortunately, use of thermalization leads to prohibitive degradation of spatial resolution. The second approach will require further experimental efforts, but scoping analyses suggest {sup 235}U- or {sup 237}Th-loaded MSNDs may achieve sufficient efficiencies. The rest of this summary examines these issues in more detail. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Neutron-detecting apparatuses and methods of fabrication

Neutron-detecting structures and methods of fabrication are provided which include: a substrate with a plurality of cavities extending into the substrate from a surface; a p-n junction within the substrate and extending, at least in part, in spaced opposing relation to inner cavity walls of the substrate defining the plurality of cavities; and a neutron-responsive material disposed within the plurality of cavities. The neutron-responsive material is responsive to neutrons absorbed for releasing ionization radiation products, and the p-n junction within the substrate spaced in opposing relation to and extending, at least in part, along the inner cavity walls of the substrate reduces leakage current of the neutron-detecting structure.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Neutron Detection in the A2 Collaboration Experiment on Neutral Pion Photo-production on Neutron

Neutron detection is of crucial importance for the neutral pion photo-production study on a neutron target that now is in progress at MAMI. Two electro-magnetic calorimeters, based on NaI and BaF 2 crystals, are used in the A2 experiment. While these calorimeters are optimized for pion decay photon detection, they have a reason able efficiency for neutron detection also. The paper describes the method, which has been used to measure this efficiency using the same data taken for pion photo-production study on deuterium target with tagged photon been of 800 MeV maximal energy. As a result, the detection efficiency is a rising function of neutron momentum that reaches 40% near 1 GeV/c.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

YAP:Ce scintillator characteristics for neutron detection

YAP:Ce (YAlO{sub 3}:Ce{sup +}, Yttrium Aluminum Perovskite, Ce{sup +} doped) crystals with appropriate converters seem like prospective scintillators for neutron detection. An important aspect for neutron detection with inorganic scintillators is the ability to discriminate neutron radiation from gamma radiation by pulse height of signals. For a detailed measurement of the aspect, a YAP:Ce crystal scintillator with lithium or hydrogen converters and a photomultiplier was used. A plutonium-beryllium neutron source and horizontal neutron channel beams of the LVR-15 research reactor were used as neutron sources. The measurement confirmed the possibility to use the YAP:Ce scintillator for neutron radiation detection. The degree of discrimination between neutron and gamma radiation for different detection configurations was studied. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Application of Neutron Detection Third Order Time Correlation

Neutron noise experiments on fissile materials are used to get information such as reactivity, fissile mass, neutron sources, prompt neutron lifetime. One of the more popular methods is based on correlated moments of the neutron counts distribution. The second correlated moment method originally proposed by Feynman was extended to the third order. In this paper we present the application of the third order correlation moments method to SILENE reactor measurements. The third order correlation moments method has been applied to analyse time list mode - subcritical measurements on SILENE reactor in order to evaluate the system subcriticality, The multiplication coefficient is obtained with large statistical uncertainties, but remains consistent with MCNP calculations. To reduce the experimental uncertainties longer measurement time and higher detector efficiency should be necessary. The systematic errors coming from the fission neutron data (moments of the fission neutron distributions) and point model formulas should also be investigated. (author)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2023

Wide band gap semiconductor NAND based neutron detection systems and methods

A wide band gap semiconductor NAND based neutron detection system includes a semiconductor layer comprising a wide band gap material with a neutron absorber material in the wide band gap material, and the semiconductor layer is the only layer of the wide band gap semiconductor NAND based neutron detection system fabricated with the neutron absorber material.

Preston, Jeffrey Robert↗
DOE OSTI2024

A comparison of the neutron detection efficiency and response characteristics of two pixelated PSD-capable organic scintillator detectors with different photo-detection readout methods

Here, we characterize the performance of two pixelated neutron detectors: a PMT-based array that utilizes Anger logic for pixel identification and a SiPM-based array that employs individual pixel readout. The SiPM-based array offers improved performance over the previously developed PMT-based detector both in terms of uniformity and neutron detection efficiency. Each detector array uses PSD-capable plastic scintillator as a detection medium. We describe the calibration and neutron efficiency measurement of both detectors using a 137 Cs source for energy calibration and a 252 Cf source for calibration of the neutron response. We find that the intrinsic neutron detection efficiency of the SiPM-based array is (30.2 ± 0.9)%, which is almost twice that of the PMT-based array, which we measure to be (16.9 ± 0.1)%.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Next-generation neutron detection using a 6 Li glass scintillator composite

Neutron detectors are crucial in fundamental science, nuclear security, safeguards, and civil applications. 3 He-filled gas proportional counters are the gold standard for thermal neutron detection, prized for their efficiency, neutron/gamma discrimination, and stability; however, the scarcity of 3 He has prompted the search for alternatives. Here, we introduce a neutron detector design based on a scintillating composite consisting of 6 Li glass scintillator particles dispersed in an organic matrix. A detector consisting of this scintillating composite, photomultiplier tubes (PMTs) for optical detection, and electronics for reading out the PMT signal in both pulse and current modes was prototyped and characterized using various neutron and gamma sources. The prototype achieves a measured intrinsic detection efficiency of 6.70 ± 0.01%, a die-away time of 10.3 ± 0.1 μs, a negligible gamma misidentification probability, and response linearity up to at least 3.7 × 10 6 incident neutrons/s established via a cross-calibration technique. This detector holds the potential to outperform traditional 3 He-gas-based neutron detection systems, offering a viable alternative amidst the ongoing 3 He shortage and promising advancements in neutron detection technology.

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

Neutron detection of the Triga Mark III reactor, using nuclear track methodology

Nuclear Track Methodology (NTM), based on the neutron-proton interaction is one often employed alternative for neutron detection. In this paper we apply NTM to determine the Triga Mark III reactor operating power and neutron flux. The facility nuclear core, loaded with 85 Highly Enriched Uranium as fuel with control rods in a demineralized water pool, provide a neutron flux around 2 × 10{sup 12} n cm{sup −2} s{sup −1}, at the irradiation channel TO-2. The neutron field is measured at this channel, using Landauer{sup ®} PADC as neutron detection material, covered by 3 mm Plexiglas{sup ®} as converter. After exposure, plastic detectors were chemically etched to make observable the formed latent tracks induced by proton recoils. The track density was determined by a custom made Digital Image Analysis System. The resulting average nuclear track density shows a direct proportionality response for reactor power in the range 0.1-7 kW. We indicate several advantages of the technique including the possibility to calibrate the neutron flux density measured at low reactor power.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Neutron detection using a current biased kinetic inductance detector

We demonstrate neutron detection using a solid state superconducting current biased kinetic inductance detector (CB-KID), which consists of a superconducting Nb meander line of 1 μm width and 40 nm thickness. {sup 10}B-enriched neutron absorber layer of 150 nm thickness is placed on top of the CB-KID. Our neutron detectors are able to operate in a wide superconducting region in the bias current–temperature diagram. This is in sharp contrast with our preceding current-biased transition edge detector, which can operate only in a narrow range just below the superconducting critical temperature. The full width at half maximum of the signals remains of the order of a few tens of ns, which confirms the high speed operation of our detectors.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2014

Neutron detection using boron gallium nitride semiconductor material

In this study, we developed a new neutron-detection device using a boron gallium nitride (BGaN) semiconductor in which the B atom acts as a neutron converter. BGaN and gallium nitride (GaN) samples were grown by metal organic vapor phase epitaxy, and their radiation detection properties were evaluated. GaN exhibited good sensitivity to α-rays but poor sensitivity to γ-rays. Moreover, we confirmed that electrons were generated in the depletion layer under neutron irradiation. This resulted in a neutron-detection signal after α-rays were generated by the capture of neutrons by the B atoms. These results prove that BGaN is useful as a neutron-detecting semiconductor material.

36 MATERIALS SCIENCE↗
DOE OSTI2020

MHD-240 Neutron Detection Efficiency and Sensitivity Calibration

The neutron detection efficiency of the MHD-240 scintillation detector was measured at Ohio University Edwards Accelerator Laboratory. Pulsed broad-spectrum sources from the 27 Al(d,n) and 9 Be(d,n) reactions were used to produce the neutrons. The neutron time-of-flight technique was used to make an energy-differential efficiency measurement. The measurements were made in a low rate pulse mode. The pulse height distribution was also recorded, and the data were used to derive a neutron sensitivity that would be applicable in a high rate environment such as a critical assembly where the detector would be expected to operate in a current mode.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Direct thermal neutron detection by the 2D semiconductor 6 LiInP 2 Se 6

Highly efficient neutron detectors are critical in many sectors, including national security, medicine, crystallography and astronomy. The main neutron detection technologies currently used involve 3 He-gas-filled proportional counters and light scintillators for thermalized neutrons. Semiconductors could provide the next generation of neutron detectors because their advantages could make them competitive with or superior to existing detectors. In particular, solids with a high concentration of high-neutron-capture nuclides (such as 6 Li, 10 B) could be used to develop smaller detectors with high intrinsic efficiencies. However, no promising materials have been reported so far for the construction of direct-conversion semiconductor detectors. Here we report on the semiconductor LiInP 2 Se 6 and demonstrate its potential as a candidate material for the direct detection of thermal neutrons at room temperature. This compound has a good thermal-neutron-capture cross-section, a suitable bandgap (2.06 electronvolts) and a favourable electronic band structure for efficient electron charge transport. We used α particles from an 241 Am source as a proxy for the neutron-capture reaction and determined that the compact two-dimensional (2D) LiInP 2 Se 6 detectors resolved the full-energy peak with an energy resolution of 13.9 per cent. Direct neutron detection from a moderated Pu–Be source was achieved using 6 Li-enriched (95 per cent) LiInP 2 Se 6 detectors with full-peak resolution. Here, we anticipate that these results will spark interest in this field and enable the replacement of 3 He counters by semiconductor-based neutron detectors.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Neutron detection apparatus and method

An apparatus for neutron detection is provided. The apparatus comprises a sensor medium in electrical contact with an electrode arrangement conformed to collect radiation-generated charge from the sensor medium. The sensor medium comprises a borazine and/or a borazine-based polymer.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Light output and neutron detection efficiency of boron-based neutron scintillator screens for neutron imaging

Recent research has explored the development of boron-based neutron scintillator screens, which potentially offer improved spatial resolution and neutron capture efficiency compared to traditional lithium-based screens. This work builds upon previous efforts to improve boron-based neutron scintillators by assessing a newer generation of boron-based scintillator screens fabricated using different compositions and fabrication approaches compared to previous generations of screens. Some of the test screens exhibit higher light output than previous efforts and higher neutron capture efficiency than lithium-based screens. This paper describes the current state of screen development, measurement results for the most recent generation of screens, and future activities.

46 - INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AN↗