A5000461706- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Radioactive contamination and transfer
- Nuclear reactor physics and engineering
- Dark Matter and Cosmic Phenomena
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
Lawrence Livermore National Laboratory
2019-2025
University of Michigan
2017-2021
This Letter reports one of the most precise measurements to date antineutrino spectrum from a purely 235U-fueled reactor, made with final dataset PROSPECT-I detector at High Flux Isotope Reactor. By extracting information previously unused segments, this analysis effectively doubles statistics previous PROSPECT measurement. The reconstructed energy is unfolded into and compared both Huber-Mueller model commercial reactor burning multiple fuel isotopes. A local excess over observed in 5–7 MeV...
The PROSPECT experiment is designed to perform precise searches for antineutrino disappearance at short distances (7–9 m) from compact nuclear reactor cores. This Letter reports results a new neutrino oscillation analysis performed using the complete data sample PROSPECT-I detector operated High Flux Isotope Reactor in 2018. uses multiperiod selection of inverse beta decay interactions with reduced backgrounds and enhanced statistical power set limits on electron caused by mixing sterile...
To date, antineutrino experiments built for the purpose of demonstrating a nonproliferation capability have typically employed organic scintillators situated as close to core possible (typically at distance few meters tens meters) and not exceeded tons in size. One problem with this approach is that proximity reactor requires accommodation by host facility. Water Cherenkov detectors located offsite, distances kilometers or greater, may facilitate nonintrusive monitoring verification...
We investigate a hypothesis that energy accumulation and the subsequent release in NaI(Tl) may lead to pulse-like events few-keV regime, phenomenon suggested by crystal manufacturing company Saint-Gobain, who provided crystals for DAMA-LIBRA. While we observed delayed long-lasting light emission 3" after exposing it UV light, consists primarily of single photons are uncorrelated with each other. also observe following gamma radiation large ionization like cosmic-ray muons. found irradiating...
We present a measurement of the rate correlated neutron captures in WATCHBOY detector, deployed at depth approximately 390 meters water equivalent (m.w.e.) Kimballton Underground Research Facility (KURF). consists cylindrical 2 ton target doped with 0.1% gadolinium, surrounded by 40 undoped hermetic shield. comparison our results expected arising from high-energy neutrons incident on outside shield, predicted hybrid FLUKA/GEANT4-based simulation. The energy distribution used simulation was...
This paper presents an energy calibration scheme for upgraded reactor antineutrino detector the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). The PROSPECT collaboration is preparing detector, PROSPECT-II (P-II), to advance capabilities investigation of fundamental neutrino physics, fission processes associated flux, nuclear security applications. P-II will expand statistical power original (P-I) dataset by at least order magnitude. new design builds upon previous P-I...
We explore the performance of a cargo screening system that consists two large-sized composite scintillation detectors and high-energy neutron interrogation source by modeling simulation. The goal is to measure β-delayed emission from an illicit special nuclear material use active interrogation. This task challenging because yield small in comparison with prompt fission secondary products, neutrons are emitted relatively low energies, high gamma backgrounds typically present. Detectors used...
When monitoring a reactor site for nuclear nonproliferation purposes, the presence of an unknown or hidden could be obscured by activities known much greater power nearby. Thus when observation antineutrino emissions, one must discriminate background fluxes from possible signals under investigation. To quantify this discrimination, we find confidence to reject (null) hypothesis single proximal reactor, exploiting directional in second, reactor. In particular, simulate inverse beta decay...
Passive detection of special nuclear material (SNM) is challenging due to its inherently low rate spontaneous emission penetrating radiation, the relative ease shielding, and fluctuating frequently overwhelming background. Active interrogation (AI), use external radiation increase characteristic from SNM, has long been considered be a promising method overcome those challenges. Current AI systems that incorporate radiography tend bremsstrahlung beams, which can deliver high doses. Low-energy...
Plastic scintillators that can discriminate between gamma rays, fast neutrons, and thermal neutrons were synthesized characterized while considering the balance processing performance at kilogram scale. These trade-offs necessitated by inclusion of 0.1 wt. % lithium-6 to enable detection neutrons. The synthesis these plastic on scale required consideration many factors. First, a comonomer (methacrylic acid) was used solubilize salts lithium-6, which allow for thermal-neutron capture reaction...
One of the two detector material choices now being considered for Mobile Antineutrino Demonstrator (MAD) project is <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Li-doped pulse shape discriminating (PSD) plastic scintillator. This new material, manufactured by Eljen and designated EJ-299-50, continues development PSD materials science group at LLNL, which invented in 2012. At present EJ-299-50 can be multi-liter volumes with...
Gamma-ray emission from special nuclear material (SNM) is relatively easy to shield detection using modest amounts of high-Z material. In contrast, fast-neutrons are much more penetrating and can escape thick shielding without losing significant energy. Furthermore, fast neutrons provide a clear unambiguous signature the presence SNM with few competing natural background sources. The challenge detecting twofold. First, neutron flux only fraction corresponding gamma-ray flux. Second, be...