A5074683887- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Nuclear Materials and Properties
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Therapy and Dosimetry
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Neutrino Physics Research
- Fusion materials and technologies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Particle Accelerators and Free-Electron Lasers
- 3D IC and TSV technologies
- Graphite, nuclear technology, radiation studies
- Radioactive Decay and Measurement Techniques
- Non-Destructive Testing Techniques
- Scientific Measurement and Uncertainty Evaluation
- Laser-induced spectroscopy and plasma
- Military Technology and Strategies
Los Alamos National Security (United States)
2020
Los Alamos National Laboratory
2009-2018
Tulane University
2008-2017
Idaho National Laboratory
2011
George Washington University
2011
Petersburg Nuclear Physics Institute
1985-2005
Japan Atomic Energy Agency
2005
Russian Academy of Sciences
1992
The most precise determination of the neutron lifetime using beam method was completed in 2005 and reported a result $\tau_n = (886.3 \pm 1.2 [\textrm{stat}] 3.2 [\textrm{syst}])$ s. dominant uncertainties were attributed to absolute fluence (2.7 s). measured with monitor that counted neutron-induced charged particles from absorption thin, well-characterized 6Li deposit. detection efficiency calculated areal density deposit, detector solid angle, evaluated nuclear data file, ENDF/B-VI...
Fission cross section ratios of 233U, 238U, 232Th, 239Pu, 237Np, natural Pb and 209Bi to 235U have been measured in a wide energy range incident neutrons from 1 MeV 200 using time-of-flight technique at the neutron spectrometer GNEIS based on 1-GeV proton synchrocyclotron PNPI. For actinide targets, threshold method evaluated data below 14 were used for normalization shape measurement data, while recommended fission sections convert ratio absolute sections. Bi an has done thickness targets...
The fragment mass and kinetic energy in neutron-induced fission of $^{238}\mathrm{U}$ has been measured for incident energies from 1 to 30 MeV at the Los Alamos Neutron Science Center. change distributions over this range were studied, transition highly asymmetric more symmetric is observed. A decrease average total $(\overline{\mathrm{TKE}})$ with increasing excitation observed, consistent previous experimental work. Additional structure multichance thresholds present...
The 233, 234, 236, 238U fission cross sections have been measured relative to 235U(n, f) for incident neutron energies from 200 KeV MeV using time-of-flight at the Los Alamos Neutron Science Center. results are generally consistent with current ENDF/B-VII evaluation, but some discrepancies previous measurements above 20 30 observed. These part of a campaign measure high precision in support fast reactor technology.
We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab be used with the GlueX experimental setup for strange hadron spectroscopy. The superior CEBAF electron will enable flux on order $1\times 10^4~K_L/sec$, which exceeds that previously attained SLAC by three orders magnitude. use deuteron target provide first measurements ever neutrons. experiment measure both differential cross sections and self-analyzed polarizations produced $Λ$, $Σ$, $Ξ$, $Ω$ hyperons using...
The normalized $^{238}$U(n,f)/$^{235}$U(n,f) cross section ratio has been measured using the NIFFTE fission Time Projection Chamber from reaction threshold to $30$~MeV. fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles neutron-induced fission. measurement was performed at Los Alamos Neutron Science Center, where neutron energy determined time-of-flight. reported here first made with...
Absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon data. These compared with most recent ENDF/B JENDL data files, the Nijmegen PWA. Systematic deviations from evaluations found to exist in low-energy region.
The neutron spectrum from neutron-induced fission needs to be known in designing new fast reactors, predicting criticality for safety analyses, and developing techniques global security application. experimental data base of spectra is very incomplete most present evaluated libraries are based on the approach Los Alamos Model. To validate these models provide improved applications, a program underway measure wide range incident energies using spallation source neutrons at Weapons Neutron...
We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The employs a novel measurement technique which is converted into proton time-of-flight asymmetry that counted directly, avoiding need for spectroscopy. Details of method, apparatus, detectors, data acquisition, and reduction scheme are presented, along with discussion important systematic effects.
A technique for establishing the total neutron rate of a highly-collimated monochromatic cold beam was demonstrated using an alpha-gamma counter. The method involves only counting measured rates and is independent cross sections, decay chain branching ratios, energy. For measurement, target 10B-enriched boron carbide totally absorbed neutrons in beam, determined by 478 keV gamma rays from capture on 10B with calibrated high-purity germanium detectors. second measurement based Bragg...