A5070303767- Nuclear Physics and Applications
- Nuclear physics research studies
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Radiation Therapy and Dosimetry
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Chemical Physics Studies
- Quantum Chromodynamics and Particle Interactions
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Medical Imaging Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Particle physics theoretical and experimental studies
- Fusion materials and technologies
- Boron Compounds in Chemistry
- Astro and Planetary Science
- Inorganic Fluorides and Related Compounds
- Nuclear Materials and Properties
- Particle Detector Development and Performance
- Radioactive Decay and Measurement Techniques
- Graphite, nuclear technology, radiation studies
- Radiopharmaceutical Chemistry and Applications
Ohio University
2015-2024
Joint Institute for Nuclear Astrophysics
2020-2023
University of Notre Dame
2012-2022
Cardiff University
2022
Medical Research Council
2022
U.S. Army Engineer Research and Development Center
2022
Houghton University
2018
Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute
2002
Lawrence Livermore National Laboratory
1983-1990
A recent study of nuclear level densities for $20<~A<~70$ found evidence that the nuclei off stability line were lower than those nearby on line. This analysis has been extended to cover mass range $20<~A<~110$ with results support original conclusions. As part study, variations energy and number parity ratio spin cutoff parameter are examined.
The thick-target neutron energy spectra of the 9Be(p,n) reaction were measured at several angles for proton-bombarding energies 3.0, 3.4, 3.7, 4.0, and 5.0 MeV. Time-of-flight techniques used to determine discriminate against background radiation. By using lithium-loaded glass scintillators low proton pulse rate frequency, have been determined as 70 keV. detectors calibrated efficiency spectrum Al(d,n) reaction, which was accurately fission chamber detectors.
We have studied states of ${}^{7}\mathrm{He}$ using the ${}^{9}\mathrm{Be}{(}^{15}\mathrm{N}{,}^{17}\mathrm{F}{)}^{7}\mathrm{He}$ reaction at two incident energies, ${E}_{\mathrm{lab}}=240$ MeV and 318.5 observed clearly first excited state ${}^{7}\mathrm{He}.$ An extended study three-body background was required to determine excitation energy width. The resonance parameters obtained for $l=1$ are ${E}_{x}=2.95(10)$ MeV, \ensuremath{\Gamma}=1.9(3) MeV. There is also evidence a broad...
The two-step cascade method previously used in neutron capture experiments is now applied to a proton reaction. spectrum of cascades populating the first 2+ level 60Ni has been measured with 59Co(p,2gamma)60Ni simulation technique for analysis allows one reveal range possible shapes both E1 and M1 gamma-strength functions. low-energy enhancement observed 3He induced reactions seen appear strength functions 60Ni.
Neutron and proton evaporation spectra from the $^{6}\mathrm{Li}+^{55}\mathrm{Mn}$ $d+^{59}\mathrm{Co}$ reactions have been analyzed with Hauser-Feshbach approach using different input models for nuclear level densities of $^{60}\mathrm{Ni}$ $^{60}\mathrm{Co}$ nuclei. It has found that a Fermi-gas like temperature dependence fail to reproduce particle both simultaneously. We obtained surprising result only way describe our data is assume independence on excitation energy up about 20 MeV range.
The neutron inelastic scattering of carbon-12, populating the Hoyle state, is a reaction interest for triple-alpha process. inverse process (neutron upscattering) can enhance state's decay rate to bound states 12C, effectively increasing overall rate. cross section this impossible measure experimentally but has been determined here at astrophysically-relevant energies using detailed balance. Using highly-collimated monoenergetic beam, we neutrons incident on Texas Active Target Time...
The energy spectra of neutrons, protons, and alpha-particles have been measured from the d+59Co 3He+58Fe reactions leading to same compound nucleus, 61$Ni. experimental cross sections compared Hauser-Feshbach model calculations using different input level density models. None them found agree with experiment. It manifests serious problem available parameterizations especially those based on neutron resonance spacings discrete levels. New densities corresponding Fermi-gas parameters obtained...
The $^{12}\mathrm{C}$($^{16}\mathrm{O}$,$^{14}\mathrm{O}$)$^{14}\mathrm{C}$ reaction was studied at a beam energy of 234 MeV. $^{14}\mathrm{O}$ ejectile detected by Q3D spectrometer forward angles. energies and angles the excited $^{14}\mathrm{C}$ recoil break-up fragments were measured in coincidence with using double sided silicon strip detector array backward A complete kinematic reconstruction performed to reconstruct...
The ${}^{18}\mathrm{F}(p,\ensuremath{\alpha}){}^{15}\mathrm{O}$ reaction is the predominant destruction mechanism in novae of radionuclide $^{18}\mathrm{F}$, a target $\ensuremath{\gamma}$-ray observatories. Thus, its rate important for understanding $^{18}\mathrm{F}$ production novae. We have studied resonances ${}^{18}\mathrm{F}+p$ system by making measurement proton-transfer ${}^{18}\mathrm{F}(d,n)$. observed 15 $^{19}\mathrm{Ne}$ levels, 5 which are below proton threshold, including...
The E1-E2 interference sign between the E(c.m.)=2.68-MeV E2 resonance and an underlying E1 strength has been measured for first time. An asymmetry parameter of a=0.07±0.05 was extracted from thick-target γ-ray yields narrow at angles 45° 135°. positive a corresponded to constructive forward and, further, allowed background be identified as below energy. E2-E2 then used evaluate global S(E2) data within vicinity 2.5≤E(c.m.)≤3.0 MeV. analysis that agreed with scenario determined scheme...
Additional experimental information concerning the level structure of $^{26}\mathrm{Si}$ above proton threshold is needed to reduce uncertainties in $^{25}\mathrm{Al}(p,\ensuremath{\gamma})^{26}\mathrm{Si}$ reaction rate and consequently better determine $^{26}\mathrm{Al}$ radioisotope production astrophysical environments. The $^{24}\mathrm{Mg}(^{3}\mathrm{He},n)^{26}\mathrm{Si}$ was measured excitation energies states were determined with improved accuracy. Spins assigned a number by...
The level densities of $^{74,76}\mathrm{Ge}$ nuclei are studied with $^{68,70}\mathrm{Zn}(^{7}\mathrm{Li},\mathrm{Xp})$ reactions. Proton evaporation spectra measured at backward angles in a wide energy region, from about 2 to 25 MeV. analysis allows for the testing density models used modern reaction codes practical cross-section calculations. Our results show that excitation energies above discrete all tested this work overestimate needed reproduce proton these Gilbert and Cameron model,...
Calibration of neutron detectors for use in measurements spanning a wide range energies is normally challenging task. Use monoenergetic beams tedious and not convenient certain energies. Measurements continuous spectrum neutrons from the 27Al(d,n) reaction at Ed = 7.44 MeV have been made with fission chamber. This should allow rapid calibration energy 0.2 ≤ En 14.5 MeV.
Nuclei reached in r- and $\mathrm{rp}$-process reactions nuclear astrophysics are considerably more neutron or proton rich than most nuclei for which level densities have been studied. Two models predict somewhat different behavior away from the valley of stability examined. It is found that one two provides a better description available data. A term lowered density parameter as isospin increased at fixed did not produce much improvement reduced based on distance stability. As by-product...