A5052736316- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear physics research studies
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Nuclear and radioactivity studies
- Particle accelerators and beam dynamics
- Medical Imaging Techniques and Applications
- Graphite, nuclear technology, radiation studies
- Geochemistry and Geologic Mapping
- Music Technology and Sound Studies
- Quantum, superfluid, helium dynamics
- Statistical Methods and Inference
- Bayesian Methods and Mixture Models
- Ion-surface interactions and analysis
- Non-Destructive Testing Techniques
- Advanced Statistical Methods and Models
- Radioactive element chemistry and processing
- Gas Dynamics and Kinetic Theory
- RFID technology advancements
- Advanced X-ray and CT Imaging
- Radiation Therapy and Dosimetry
- Scientific Computing and Data Management
- Engineering Applied Research
Los Alamos National Laboratory
2012-2025
Computational Physics (United States)
2020
University of Michigan
2013-2019
The detection and characterization of highly enriched uranium (HEU) presents a large challenge in the non-proliferation field. HEU has low neutron emission rate most gamma rays are energy easily shielded. To address this challenge, an instrument known as dual-particle imager (DPI) was used with portable deuterium-tritium (DT) generator to detect neutrons from induced fission HEU. We evaluated system response using 13.7-kg sphere several configurations no moderation, high-density polyethylene...
Neutron multiplicity counting (NMC) techniques are widely used for nuclear materials accountability and international safeguards applications to quantitatively evaluate characteristic properties pertaining fissile material. Mathematical models NMC moments have been previously derived systems that use capture-based detectors; however, these not applicable when scatter-based detectors because of "neutron cross talk." talk occurs a single neutron scatters deposits energy above threshold into...
This paper presents new experimental results of correlated, prompt neutron emission from the spontaneous fission 252Cf. Specifically, we present correlated-neutron probabilities and average energies for two detected neutrons as a function angle between neutrons. Experimental are compared to several Monte Carlo models that include number, energy, angular distributions fission.
Neutrons and photons are characteristically emitted during the nuclear fission process when a deformed, neutron-rich nucleus divides into two fragments that then deexcite. During deexcitation, neutrons first, followed by photons; this gives rise to correlated emissions. Few data exist on event-by-event neutron-photon correlation. In work, $^{252}\mathrm{Cf}(\mathrm{s}\mathrm{f})$ neutron photon correlations were measured with an array of 45 liquid organic scintillation detectors chamber. The...
Correlated neutrons from a Cf-252 spontaneous fission source were measured with coincidence detection system. The system consisted of three EJ-309 cylindrical liquid scintillators (length and diameter 7.62 cm) configured to quantify the effects neutron cross-talk on total observed correlated counts. Because scatter-based detectors are susceptible cross-talk, discrimination between true counts is significant for measurements. This measurement aimed mitigate adequate polyethylene shielding,...
Background: Spontaneous fission events emit prompt neutrons correlated with one another in emission angle and energy. Measurements of these correlations can shed light on the partitioning excitation energy between fragments, even if they are not directly measured.Purpose: We explore relationship emitted from $^{252}\mathrm{Cf}$ spontaneous fission.Methods: Chi-Nu array provide experimental data for coincident tagged a chamber signal ${10}^{\ensuremath{\circ}}$ angular resolution 1-ns timing...
New event-by-event fission models have prompt neutrons and gamma-rays that are correlated in time, energy, multiplicity, however there is limited measurement data available to validate these models. Measurement of high-order neutron gamma-ray coincidences difficult has previously been little motivation measure properties both particle types simultaneously. High-order Cf-252 spontaneous were measured with a cylindrical array 22 liquid organic 8 NaI(Tl) scintillation detectors, 50 cm from...
A plutonium metal sample was measured by a fast-neutron multiplicity counter for characterization of spontaneous fission neutron anisotropy and verification MCNPX-PoliMi calculations. Accurate angular distribution models are important to properly simulating fast coincidence measurements nuclear nonproliferation safeguards applications. majority prompt neutrons emitted from fully accelerated fragments; those carry momentum the fragments, thus an anisotropic is observed in laboratory reference...
Monte Carlo particle transport codes used to model detector responses are traditionally run in analog mode. However, simulations of cross-correlation measurements extremely time-consuming because the probability coincident detection is small, approximately equal product probabilities a single each detector. The new implicit correlation method described here increases number correlated event scores, thereby reducing variance and required computation times. cost comparable simulating...
New event-by-event fission models have prompt neutron and gamma-rays that are correlated in time, energy, multiplicity, however there is limited measurement data available to validate these models. Measurement of high-order gamma-ray coincidences difficult has previously been little motivation measure properties both particle types simultaneously. High-order Cf-252 spontaneous were measured with an array 24 liquid organic eight sodium iodide scintillation detectors. Measured coincidence...