R. C. Haight
A5019341852- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Radiation Therapy and Dosimetry
- Nuclear Materials and Properties
- X-ray Spectroscopy and Fluorescence Analysis
- Astro and Planetary Science
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Graphite, nuclear technology, radiation studies
- Magnetic confinement fusion research
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Fusion materials and technologies
- Cold Fusion and Nuclear Reactions
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- High-pressure geophysics and materials
Los Alamos National Laboratory
2015-2024
University of North Texas
2015-2024
University of North Texas Health Science Center
2015-2024
University of North Texas System
2015-2024
Ohio University
1983-2022
Larkin University
2021
International Atomic Energy Agency
2020
Los Alamos National Security (United States)
2007-2017
Regis University
2015-2017
Lawrence Livermore National Laboratory
1981-2014
Neutrons are unique particles to probe samples in many fields of research ranging from biology material sciences engineering and security applications. Access bright, pulsed sources is currently limited large accelerator facilities there has been a growing need for compact over the recent years. Short pulse laser driven neutron could be relatively cheap way produce neutrons with energies excess 10 MeV. For more than decade experiments have tried obtain numbers sufficient Our demonstrated an...
We have completed a new set of total cross section measurements 31 elements and isotopes spanning the periodic table from A=1 to 238. employed same technique as in Finley et al. [Phys. Rev. C 47, 237 (1993)] with refinements intended allow on separated improved systematic error control. The goal measurement was 1% statistical accuracy energy bins errors less than 1%. This achieved for all but thinnest samples. Stringent checks this resulted reassignment uncertainties neutron sections...
Pulsed-beam time-of-flight techniques are used in a transmission measurement with continuous spectrum of neutrons to determine neutron total cross sections good precision up 600 MeV. Neutrons produced by spallation the 800 MeV proton beam from Los Alamos Meson Physics Facility accelerator incident on thick, heavily shielded tungsten target at Weapons Neutron Research facility National Laboratory. Transmission measurements were completed for fifteen elements...
Cross sections have been measured for the emission of protons, deuterons, and alpha particles 15-MeV neutrons on $^{54,56}\mathrm{Fe}$, $^{58,60}\mathrm{Ni}$, $^{50,52}\mathrm{Cr}$, $^{63,65}\mathrm{Cu}$, as well natural iron, nickel, chromium. A quadrupole spectrometer served to detect with energies low 1 MeV. For some targets, a substantial fraction charged-particle spectrum is at below Coulomb barrier. spectra are compared statistical pre-equilibrium model predictions.NUCLEAR REACTIONS...
Deuterium adsorption on the clean Si(111)–(7×7) surface was quantitatively studied by determining absolute coverage as a function of exposure using nuclear microanalysis. The correlated with structural changes seen low energy electron diffraction and high ion scattering peak. A saturation 1.25±0.13 monolayers established for activated deuterium adsorption.
A high-resolution measurement of the neutron-induced fission cross section $^{234}\mathrm{U}$ and $^{237}\mathrm{Np}$ has been performed at CERN Neutron Time-of-Flight facility. The sections have determined in a wide energy range from 1 eV to GeV using evaluated $^{235}\mathrm{U}$ as reference. In these measurements determination for resonances could be improved, whereas previous discrepancies were confirmed. New cross-section data are provided high neutron energies that go beyond limits...
The cross section of the reaction $^{197}\mathrm{Au}$($n,\ensuremath{\gamma}$) was measured with time-of-flight technique at n_TOF (neutron time-of-flight) facility in unresolved resonance region between 5 and 400 keV using a pair ${\mathrm{C}}_{6}$D${}_{6}$ (where D denotes $^{2}\mathrm{H}$) liquid scintillators for detection prompt capture $\ensuremath{\gamma}$ rays. results total uncertainty $3.9%--6.7$$%$ resolution 20 bins per energy decade show fair agreement Evaluated Nuclear Data...
We have measured the neutron capture cross sections of stable magnesium isotopes ${}^{24,25,26}$Mg in energy range interest to $s$ process using time-of-flight facility n_TOF at CERN. Capture events from a natural metal sample and samples enriched ${}^{25}$Mg ${}^{26}$Mg were recorded total method based on C${}_{6}$${}^{2}$H${}_{6}$ detectors. Neutron resonance parameters extracted by simultaneous shape analysis present data existing transmission isotopic sample. Maxwellian-averaged for...
The neutron capture cross section of $^{241}\mathrm{Am}$ for incident neutrons from 0.02 eV to 320 keV has been measured with the detector advanced experiments (DANCE) at Los Alamos Neutron Science Center. thermal was determined be $665\ifmmode\pm\else\textpm\fi{}33$ b. Our result is in good agreement other recent measurements. Resonance parameters ${E}_{n}<12$ were obtained using an $R$-matrix fit section. results are compared values ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1...
The total $^{7}\mathrm{Be}$(n,p${)}^{7}$Li cross section has been measured from 25 meV to 13.5 keV. These energies correspond temperatures of T=2.9\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}7}$ 0.16 GK. For thermal neutrons the sections ground state (${p}_{0}$) and first excited (${\mathit{p}}_{1}$) $^{7}\mathrm{BLi}$ are 38 400\ifmmode\pm\else\textpm\fi{}800 b 420\ifmmode\pm\else\textpm\fi{}120 b, respectively. This result for is about 25% lower, approximately a factor...
The ($n,\ensuremath{\gamma}$) cross section of $^{197}\mathrm{Au}$ has been measured at n_TOF in the resolved resonance region, up to 5 keV, with aim improving accuracy an energy range where it is not yet considered standard. measurements were performed two different experimental setup and detection techniques, total method based on ${\mathrm{C}}_{6}$${\mathrm{D}}_{6}$ detectors, absorption calorimetry a 4$\ensuremath{\pi}$ BaF${}_{2}$ array. By comparing data collected accurate sets...
The prompt $\ensuremath{\gamma}$-ray energy and multiplicity distributions in the spontaneous fission of ${}^{252}$Cf have been measured using a highly segmented 4$\ensuremath{\pi}$ calorimeter. Corrections were made for both according to detector response, which is simulated numerically model validated with calibration sources. A comparison total distribution was between measurement simulation performed by random sampling corrected then transporting those $\ensuremath{\gamma}$ rays through...
We present a full characterization of short pulse laser-driven neutron source. Neutrons are produced by nuclear reactions ions deposited in secondary target. The emission neutrons is superposition an isotropic component into 4π and forward directed, jet-like contribution, with energies ranging up to 80 MeV. A maximum flux 4.4 × 109 neutrons/sr has been observed used for fast radiography. On-shot the ion driver beam done variety different diagnostics, including particle detectors, reaction,...
Background: Accurate knowledge of the $^{238}\mathrm{U}$($n$,$\ensuremath{\gamma}$) cross section is important for developing theoretical nuclear reaction models and applications. However, capture sections are difficult to calculate accurately often must be measured.Purpose: We seek confirm previous measurements test cross-section calculations with an emphasis on unresolved resonance region from 1 500 keV.Method: Cross were measured 10 eV keV using DANCE detector array at LANSCE spallation...
New prompt fission neutron spectrum measurements are reported for 235U(n,f) reactions induced by neutrons with energies from 0.7 to 20 MeV. These cover outgoing 2.5 MeV down 10 keV, using an array of 6Li-glass scintillators detection and a double time-of-flight technique. The were produced at the Weapons Neutron Research facility Los Alamos Science Center. A detailed MCNP® model experimental equipment surrounding room was used interpret results. Backgrounds measured in situ, making use...
Emerging approaches to short-pulse laser-driven neutron production offer a possible gateway compact, low cost, and intense broad spectrum sources for wide variety of applications. They are based on energetic ions, driven by an laser, interacting with converter material produce neutrons via breakup nuclear reactions. Recent experiments performed the high-contrast laser at Trident facility Los Alamos National Laboratory have demonstrated ion acceleration mechanism operating in regime...