Final LDRD report : advanced plastic scintillators for neutron detection.

Vance, Andrew L.; Mascarenhas, Nicholas; O'Bryan, Greg; Mrowka, Stanley

doi:10.2172/990072

Cited by 4 publications

(3 citation statements)

References 9 publications

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“…Earlier attempts to obtain efficient PSD in plastic scintillators in the past resulted in unstable materials 19 or inability to achieve neutron/gamma discrimination of any practically useful level. 20 One of the reasons that led to consideration of plastics as materials not capable of PSD was the low concentration (~1-5 wt %) of scintillating dyes traditionally used for plastic preparation. To develop the first plastic scintillators with efficient PSD, the dye loads were shifted into the range of larger concentrations of 20-30 wt %, using a highly soluble scintillation dye, 2,5diphenyloxazole, PPO (Fig.…”

Section: Psd Plastics For Fast Neutron Detectionmentioning

confidence: 99%

New solid-state organic scintillators for fast and thermal neutron detection

Zaitseva

Glenn

Mabe

et al. 2020

Int. J. Mod. Phys. Conf. Ser.

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Detection of special nuclear materials (SNM) requires instruments that can detect and characterize uranium and plutonium isotopes, having at the same time the ability to discriminate among different types of radiation. For many decades, neutron detection has been based on 3He proportional counters sensitive primarily to thermal neutrons. The most common methods for detection of fast neutrons have been based on liquid scintillators with pulse shape discrimination (PSD). The shortage of 3He and handling issues with liquid scintillators stimulated a search for efficient solid-state PSD materials. Recent studies conducted at LLNL led to development of new materials, among which are organic crystals with excellent PSD and first PSD plastics for fast neutron detection. More advantages are introduced by plastics doped with neutron capture agents, such as 10B and 6Li, that can be used without moderation for combined detection of both thermal and fast neutrons, offering, in addition, a unique “triple” PSD for signal separation between fast neutrons, thermal neutrons, and gamma-rays. More recent studies have been focused on development of deuterated scintillators that can be used for neutron spectroscopy without time-of-flight (ToF). Among commercially produced materials are large-scale (>10 cm) stilbene crystals grown by the inexpensive solution technique, and different types of PSD plastics that, due to the deployment advantages and ease of fabrication, create a basis for the widespread use of solid-state scintillators as large-volume and low-cost neutron detectors.

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Section: Psd Plastics For Fast Neutron Detectionmentioning

confidence: 99%

New solid-state organic scintillators for fast and thermal neutron detection

Zaitseva

Glenn

Mabe

et al. 2020

Int. J. Mod. Phys. Conf. Ser.

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“…A promising alternative to improve plastic scintillator properties, such as dopant aggregation and leaching, is to covalently attach the dopant to the matrix via copolymerization. This approach has recently been reported in the literature , with 50 wt % of a cross-linkable derivative of 9,10-diphenylanthracene (DPPA), resulting in a scintillator with relatively low PSD . Furthermore, DPPA required a five-step synthetic process with pyrophoric reagents and a low overall reaction yield which is not ideal for large-scale synthesis needed to commercialize this technology.…”

Section: Introductionmentioning

confidence: 99%

Methacrylate-Functionalized 2,5-Diphenyloxazole for Use as Fluorescent Monomers in Plastic Scintillators

Lim

Hernández

Latta

et al. 2019

ACS Appl. Polym. Mater.

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Interest in plastic scintillators for the detection of special nuclear materials (SNMs) has increased in recent years due to the development of systems capable of distinguishing between neutron and γ radiation. For example, poly(vinyltoluene) (PVT)-based scintillators overdoped with the fluorescent small molecule 2,5-diphenyloxazole (PPO) distinguish the two types of radiation via pulse shape discrimination (PSD). However, PPO overdoping leads to softening of the plastic and dopant aggregation, causing major issues with detection efficiency, lifetime, and scalability. To improve the plastic scintillator properties while retaining efficient PSD performance, methacrylate-based derivatives of PPO were synthesized for copolymerization with vinyltoluene. The use of polymerizable dopants results in PSD capable plastic scintillators with increased mechanical and thermal stability while eliminating dopant aggregation and leaching.

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“…It works but the final cost makes it unusable for Homeland security applications. That's the reason why our lab has carried on research on the signal analysis from plastic scintillators for gamma neutron discrimination, rather than working on the material [5,9]. In fact some shows that there is a correlation between the crystal nature of the organic material and their ability to discriminate neutron from gamma rays [13].…”

Section: Introductionmentioning

confidence: 99%

MA-NRBC: First successful attempt for neutron gamma discrimination in plastic scintillators

Normand

Kondrasovs

Corre

et al. 2011

2011 2nd International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and Their Applications

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In this paper, a new electronic hardware and algorithms enabling discrimination between neutron and gamma in plastic scintillators together with the first associated experimental results, are presented. This electronic platform is mainly based onto a quad 200 MHz ADCs. Using phase rotating, it is possible to sample the signal up to 800 MHz equivalent, with 8 bits precision. This sampling frequency allows a real time signal processing. Despite all previous work, we have shown during this study that it is possible to discriminate neutron from gamma in plastic scintillators even for low energy neutrons (less than 10 MeV). Two patents have been accepted and registered; the first deals with the intrinsic signal processing and the second with thermal stabilization methods of photomultiplier tubes. The system could be used up to 100 000 events per second (both gamma and neutron). This system is currently dedicated to homeland security devices; this is due to its response time (in the order of 1 up to 3 seconds). The next step is to implement the thermal stabilization algorithm in the FPGA and microcontroller to obtain a global system free from any trouble caused by the environment thermal variations. This aspect of the research is crucial for measurements in the field. The time response should also be improved to make it a reliable alternative to Helium-3 shortage for neutron detection at borders checkpoint.

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Final LDRD report : advanced plastic scintillators for neutron detection.

Cited by 4 publications

References 9 publications

New solid-state organic scintillators for fast and thermal neutron detection

New solid-state organic scintillators for fast and thermal neutron detection

Methacrylate-Functionalized 2,5-Diphenyloxazole for Use as Fluorescent Monomers in Plastic Scintillators

MA-NRBC: First successful attempt for neutron gamma discrimination in plastic scintillators

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