A5083769535- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Nuclear reactor physics and engineering
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Atmospheric Ozone and Climate
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Cold Fusion and Nuclear Reactions
- Particle physics theoretical and experimental studies
- Radioactivity and Radon Measurements
- Rare-earth and actinide compounds
- Laser-induced spectroscopy and plasma
- Spectroscopy and Laser Applications
- Fault Detection and Control Systems
- Fusion materials and technologies
- Radiation Therapy and Dosimetry
University of Notre Dame
2015-2024
Joint Institute for Nuclear Astrophysics
2017-2022
Texas A&M University
2020
Carbon and oxygen burning reactions, in particular, $^{12}$C+$^{12}$C fusion, are important for the understanding interpretation of late phases stellar evolution as well ignition nucleosynthesis cataclysmic binary systems such type Ia supernovae x-ray superbursts. A new measurement this reaction has been performed at University Notre Dame using particle-$\gamma$ coincidence techniques with SAND (a silicon detector array) high-intensity 5U Pelletron accelerator. New results fusion low...
The dark matter interpretation of the DAMA modulation signal depends on NaI(Tl) scintillation efficiency nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in DAMA/LIBRA energy region. We report a quenching effect measurement from 3 to $52 {\mathrm{keV}}_{\text{nr}}$, covering whole region matter-Na scattering interpretations. By using low-energy, pulsed neutron beam, double time-of-flight technique, and pulse-shape discrimination methods, we obtained...
The total cross section of the $^{12}\mathrm{C}+^{16}\mathrm{O}$ fusion reaction has been measured at low energies to investigate role this during late stellar evolution burning phases. A high-intensity oxygen beam, produced by 5 MV pelletron accelerator University Notre Dame, impinged on a thick, ultrapure graphite target. Protons and $\ensuremath{\gamma}$ rays were simultaneously in center-of-mass energy range from 3.64 5.01 MeV for singles 3.73 4.84 coincidence events, using silicon Ge...
Quasi-elastic scattering measurements have been performed using 16O and 24Mg projectiles off 90Zr at energies around the Coulomb barrier. Experimental data analyzed in framework of coupled channels (CC) calculations code CCFULL. The quasi-elastic excitation function derived barrier distribution for + reaction are well reproduced by CC vibrational coupling strengths reported literature. Using these strengths, a Bayesian analysis is carried out reaction. β2 β4 values determined to be...
Precise antineutrino measurements are very sensitive to proper background characterization. We present an improved measurement of the ^{13}C(α,n)^{16}O reaction cross section which constitutes significant for large ν[over ¯] detectors. greatly improve precision and accuracy by utilizing a setup that is neutron energies while making excited state transitions via secondary γ-ray detection. Our results shows 54% reduction in contributions from ^{16}O(3^{-},6.13 MeV) used KamLAND analysis.
Nucleosynthesis in the first generation of massive stars offers a unique setting to explore creation heavier nuclei an environment free impurities from earlier stellar generations. In later generations stars, hydrogen burning occurs predominantly through CNO cycles, but without carbon, nitrogen, and oxygen catalyze reaction sequence, would have rely on inefficient pp chains for their energy production. Observations second third show pronounced abundances carbon isotopes, which suggests rapid...
Background: A multitude of broad interfering resonances characterize the $^{10}\mathrm{B}(p,\ensuremath{\alpha})^{7}\mathrm{Be}$ cross section at low energies. The complexity reaction mechanism, as well conflicting experimental measurements, have so far prevented a reliable prediction over energy ranges pertinent for boron-proton fusion reactor environment.Purpose: To improve evaluated reaction, this study targets proton region from 0.8 to 2.0 MeV, where kinematic overlap scattered protons...
Background: The precise determination of the $\mathcal{F}t$ value in $T=1/2$ mixed mirror decays is an important avenue for testing standard model electroweak interaction through ${V}_{ud}$ nuclear $\ensuremath{\beta}$ decays. $^{11}\mathrm{C}$ interesting case, as its low mass and small ${Q}_{EC}$ make it particularly sensitive to violations conserved vector current hypothesis. present dominant source uncertainty $^{11}\mathrm{C}\phantom{\rule{4pt}{0ex}}\mathcal{F}t$ half-life.Purpose: A...
Background: The reaction $^{20}\mathrm{Ne}(p,\ensuremath{\gamma})^{21}\mathrm{Na}$ influences the nucleosynthesis of Ne, Na, and Mg isotopes while contributing to hydrogen burning in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive oxygen-neon (ONe) novae. In relevant temperature range for these environments ($T$ = 0.05--0.5 GK), main contributions this rate are from direct capture process well high-energy tail a subthreshold resonance ground-state...
The CNO cycle is the main energy source in massive stars during their hydrogen burning phase, and, for our sun, it contributes at $\ensuremath{\approx}1%$ level. As $^{14}\mathrm{N}(p,\ensuremath{\gamma})^{15}\mathrm{O}$ reaction slowest cycle, determines production rate and thus contribution to solar neutrino flux. These neutrinos are produced primarily from $\ensuremath{\beta}$ decay of $^{15}\mathrm{O}$ a lesser extent, $^{13}\mathrm{N}$. Solar challenging detect, but they can provide...
A new precision half-life measurement of $^{29}\mathrm{P}$ was conducted using the TwinSol $\ensuremath{\beta}$-counting station at University Notre Dame Nuclear Science Laboratory. The resulting value ${t}_{1/2}^{\mathrm{new}}=4.1055(44)\phantom{\rule{0.28em}{0ex}}\mathrm{s}$ is most precise to date. Utilizing this and reevaluating world data leads a average ${t}_{1/2}^{\mathrm{world}}=4.1031(58)\phantom{\rule{0.28em}{0ex}}\mathrm{s}$, which improves Birge ratio from 3.11 1.45 2.3 times...
The National Ignition Facility (NIF) provides the opportunity to study nuclear reactions under controlled conditions at high temperatures and pressures a level never before achieved. However, timescale of deuterium-tritium (DT) implosion is only few nanoseconds, making data collection diagnostics very challenging. One method that has been proposed for obtaining additional information about activate dopant material using $\ensuremath{\alpha}$ particles produced from DT fuel as diagnostic....
The $^{23}\mathrm{Na}(p,\ensuremath{\gamma})^{24}\mathrm{Mg}$ reaction plays an important role in the nucleosynthesis of elements hot bottom burning environment asymptotic giant branch stars by providing a breakout path from NeNa cycle to MgAl cycle. At temperatures above $\ensuremath{\approx}0.06$ GK, underlying nuclear contributions rate are primarily narrow resonances, but at lower direct and broad resonance tail come dominate. While there have been recent studies improve uncertainties...
Abstract Reactions that populate the 15 N system have implications for nucleosynthesis through 11 B( α, n ) 14 and N( n, p C reactions reaction is also a key component in modeling atmospheric production. A convenient characteristic of this α -particle, proton, neutron separation energies are all within ≍1 MeV one another. Further, it has been observed B+ , N+ C+ induced many same resonances near their thresholds. This strongly facilitates simultaneous analysis data three these entrance...
Abstract The first measurements of the capture reactions for astrophysical γ-process using HECTOR, a total absorption spectrometer are presented. Two reactions: 102 Pd(p,γ) 103 Ag and 90 Zr(α,γ) 94 Mo were measured γ-summing technique. results compared with previous found in literature NON-SMOKER predictions. from current work good agreement data serve as test newly developed detector.
A direct test of nova explosion models comes from the observation γ rays created in decay radioactive isotopes produced nova. One such isotope, 18F, is believed to be main source observable at and below 511 keV. The destruction mechanism 18F thought 18F(p,α)15O reaction, uncertainties reaction rate arise energies, spins, parities nuclear levels 19Ne above 18F+p threshold. To measure properties these levels, 19F(3He,t)19Ne∗(γ) was studied Argonne National Laboratory Nuclear Science University...
Energy production in Type Ia x-ray bursts depends on a number of nuclear reactions that become efficient hot environment (up to 2 GK). Model sensitivity studies have been performed an effort better identify the largest effect, but these efforts are hampered by high level complexity astrophysical model and large physics uncertainties. In recent study, $^{24}\mathrm{Mg}(\ensuremath{\alpha},p)^{27}\mathrm{Al}$ reaction was found significantly affect energy generation bursts. This manuscript...
The observation of secondary $\ensuremath{\gamma}$-rays provides an alternative method measuring cross sections that populate excited final states in nuclear reactions. angular distributions these also provide information on the underlying reaction mechanism. Despite large number data this type literature, publicly available $R$-matrix codes do not have ability to calculate types distributions. In paper, mathematical formalism derived by C. R. Brune and J. deBoer [Phys. Rev. C 102, 024628...