<sup>6</sup>LiF:ZnS(Ag) Neutron Detector Performance Optimized Using Waveform Recordings and ROC Curves

Pritchard, K.; Majkrzak, C. F.; Maliszewskyj, Nicholas C.; Osovizky, A.; Ziegler, J.; Binkley, Edward S.; Tsai, P.; Hadad, N.; Jackson, M. S.; Hurlbut, C.; Baltic, G.M.

doi:10.1109/tns.2019.2953875

Cited by 7 publications

(5 citation statements)

References 27 publications

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“…The CANDOR detector is a channel with an array of 54 single-blade HOPG crystals in series at fixed angles to select neutrons in the 4-6 A ˚wavelength range. As the polychromatic scattered beam passes each crystal, neutrons of the corresponding wavelength are diffracted into scintillation detectors (Pritchard et al, 2020) located along the side of the channel [the bottom solid line in Fig. 1(e)].…”

Section: Methodsmentioning

confidence: 99%

Low-background neutron reflectometry from solid/liquid interfaces

Hoogerheide¹,

Dura²,

Maranville³

et al. 2022

J Appl Crystallogr

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Liquid cells are an increasingly common sample environment for neutron reflectometry experiments and are critical for measuring the properties of materials at solid/liquid interfaces. Background scattering determines the maximum useful scattering vector, and hence the spatial resolution, of the neutron reflectometry measurement. The primary sources of background are the liquid in the cell reservoir and the materials forming the liquid cell itself. Thus, characterization and mitigation of these background sources are necessary for improvements in the signal-to-background ratio and resolution of neutron reflectometry measurements employing liquid cells. Single-crystal silicon is a common material used for liquid cells due to its low incoherent scattering cross section for neutrons, and the path lengths of the neutron beam through silicon can be several centimetres in modern cell designs. Here, a liquid cell is constructed with a sub-50 µm thick liquid reservoir encased in single-crystal silicon. It is shown that, at high scattering vectors, inelastic scattering from silicon represents a significant portion of the scattering background and is, moreover, structured, confounding efforts to correct for it by established background subtraction techniques. A significant improvement in the measurement quality is achieved using energy-analyzed detection. Energy-analyzed detection reduces the scattering background from silicon by nearly an order of magnitude, and from fluids such as air and liquids by smaller but significant factors. Combining thin liquid reservoirs with energy-analyzed detection and the high flux of the CANDOR polychromatic reflectometer at the NIST Center for Neutron Research, a background-subtracted neutron reflectivity smaller than 10−8 from a liquid cell sample is reported.

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Section: Methodsmentioning

confidence: 99%

Low-background neutron reflectometry from solid/liquid interfaces

Hoogerheide¹,

Dura²,

Maranville³

et al. 2022

J Appl Crystallogr

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“…The 1 st and 2 nd integral periods used for these figures are 0 ns to 240 ns and 240 ns to 2240 ns respectively. The optimization of the CC algorithm for our application is discussed elsewhere [18]. The focus here is not on the CC algorithm, but on quickly rejecting noise and pile-up events which trigger the CC algorithm at rates sometimes exceeding 1 kHz resulting in processing deadtime while these pulses are integrated and evaluated.…”

Section: Fig 2 Photograph Of the Candor_daqmentioning

confidence: 99%

“…Fig. 21 shows two receiver operating characteristic (ROC) curves [18], [78], one including the pile-up filter and one omitting the pile-up filter. The comparison shows the pile-up filter improves performance modestly (about a 1% increase to neutron ID rate at 10E-7 gamma rejection).…”

Section: Pile-up Filtermentioning

confidence: 99%

“…1. More information can be found regarding the scintillator composition [13], [14], the design and optimization [15], [16], the SiPM [17], signal processing [18], service lifetime [19], and deadtime analysis [20].…”

Section: Introductionmentioning

confidence: 99%

“…Our Co-60 data yielded useful illustrations, but it was not used for quantitative algorithm comparisons, because this data was taken while our reactor was operating and contained a significant neutron background. This neutron background has the effect of obscuring differences observed at very high gamma rejection ratios.Fig.21shows two receiver operating characteristic (ROC) curves[18],[78], one including the pile-up filter and one omitting the pile-up filter. The comparison shows the pile-up filter improves performance modestly (about a 1% increase to neutron ID rate at 10E-7 gamma rejection).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Real-Time Signal Processing for Mitigating SiPM Dark Noise Effects in a Scintillating Neutron Detector

Pritchard

Chabot

Robucci

et al. 2021

IEEE Trans. Nucl. Sci.

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A 6 LiF:ZnS(Ag) based cold neutron detector with wavelength shifting (WLS) fibers and SiPM photodetector was developed at the NIST Center for Neutron Research. For neutron scattering applications at the NCNR, detector false positives severely diminish the quality of very faint neutron scatter patterns. Thermal noise generated by the SiPM significantly increases the likelihood of false positives by the detector/discriminator. This paper describes and evaluates a digital real-time algorithm implemented on a field programmable gate array (FPGA) which quickly differentiates SiPM thermal noise and noise pulse pile-up from neutron signals. The algorithm reduces deadtime spent on examining noise pulses as well as reduces the number of false positives.

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The Detection of Slow Neutrons

Dumazert

Frangville

2021

Topics in Applied Physics

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⁶LiF:ZnS(Ag) Neutron Detector Performance Optimized Using Waveform Recordings and ROC Curves

Cited by 7 publications

References 27 publications

Low-background neutron reflectometry from solid/liquid interfaces

Low-background neutron reflectometry from solid/liquid interfaces

Real-Time Signal Processing for Mitigating SiPM Dark Noise Effects in a Scintillating Neutron Detector

The Detection of Slow Neutrons

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6LiF:ZnS(Ag) Neutron Detector Performance Optimized Using Waveform Recordings and ROC Curves

Cited by 7 publications

References 27 publications

Low-background neutron reflectometry from solid/liquid interfaces

Low-background neutron reflectometry from solid/liquid interfaces

Real-Time Signal Processing for Mitigating SiPM Dark Noise Effects in a Scintillating Neutron Detector

The Detection of Slow Neutrons

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Product

Resources

About

⁶LiF:ZnS(Ag) Neutron Detector Performance Optimized Using Waveform Recordings and ROC Curves