A5065382782- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Quantum Chromodynamics and Particle Interactions
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Nuclear reactor physics and engineering
- Neutrino Physics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Advanced Chemical Physics Studies
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Gamma-ray bursts and supernovae
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Spacecraft and Cryogenic Technologies
TRIUMF
2016-2025
University of Exeter
2024
University of Victoria
2020-2023
Joint Institute for Nuclear Astrophysics
2020
Michigan State University
2020
University of Wisconsin–Madison
2016
Sandia National Laboratories
2014-2015
Instituto de Ciencia de Materiales de Madrid
2011
Simon Fraser University
2005-2006
University of Edinburgh
2001-2006
Despite their high relative abundance in our Universe, neutrinos are the least understood fundamental particles of nature. They also provide a unique system to study quantum coherence and wavelike nature systems due extremely weak interaction probabilities. In fact, properties emitted experimentally relevant sources virtually unknown spatial extent neutrino wavepacket is only loosely constrained by reactor oscillation data with spread 13 orders magnitude. Here, we present first direct limits...
The reaction $^{6}\mathrm{He}+^{64}\mathrm{Zn}$ was studied in order to investigate the effects of projectile neutron-halo structure on mechanism at energies around Coulomb barrier. Elastic scattering angular distributions, transfer∕breakup and fusion excitation functions have been measured. Due low-recoil energy evaporation residues low intensity $^{6}\mathrm{He}$ beam, cross section measured by detecting off-line atomic x-ray emission which follows electron capture decay residues. For...
Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing physics of burn product confinement. Diagnosing level magnetization during is critical to understanding target performance magneto-inertial (MIF) implosions. In pure deuterium plasma, 1.01 MeV tritons are emitted deuterium-deuterium can undergo secondary deuterium-tritium reactions before exiting fuel. Increasing elongates path lengths through some tritons,...
The magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of confinement fusion. first experiments test [M. R. Gomez Rev. Lett. 113, 155003 (2014)] were conducted utilizing 19 MA, 100 ns Z machine, 2.5 kJ, 1 TW Beamlet laser, 10 T Applied B-field on system. Despite an estimated implosion velocity only 70 km/s in these experiments, electron ion temperatures at stagnation as...
Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal dark sector. We report new search for existence sub-MeV sterile using decay-momentum reconstruction technique in decay $^{7}\mathrm{Be}$. The experiment measures total energy $^{7}\mathrm{Li}$ daughter atom from electron capture $^{7}\mathrm{Be}$ implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first presents data single STJ operated at low...
The Beryllium Electron capture in Superconducting Tunnel junctions (BeEST) experiment searches for evidence of heavy neutrino mass eigenstates the nuclear electron decay $^7$Be by precisely measuring recoil energy $^7$Li daughter. In Phase-III, BeEST has been scaled from a single superconducting tunnel junction (STJ) sensor to 36-pixel array increase sensitivity and mitigate gamma-induced backgrounds. Phase-III also uses new continuous data acquisition system that greatly increases...
The s-wave neutron fraction of the 0+ levels in 12Be has been investigated for first time through 11Be(d,p) transfer reaction using a 5A MeV 11Be beam at TRIUMF, Canada. populated all known bound states 12Be. ground state spectroscopic factor was determined to be 0.28−0.07+0.03 while that long-lived 02+ excited 0.73−0.40+0.27. This observation, together with smaller effective separation energy indicates enhanced probability an extended density tail beyond 10Be core compared state.
The ${}^{18}\text{F}(p,\ensuremath{\alpha}){}^{15}$O reaction rate is crucial for understanding the final abundance of $^{18}\mathrm{F}$ predicted by nova models. $\ensuremath{\gamma}$-ray emission in first few hours after a outburst expected to be dominated 511 keV annihilation photons from decay $^{18}\mathrm{F}$, and so its production can provide important constraints on conditions during when compared with observations. Results are presented lowest-energy direct measurement date,...
This Letter reports a study of the highly debated $^{10}\mathrm{Li}$ structure through $d(^{9}\mathrm{Li},p)^{10}\mathrm{Li}$ one-neutron transfer reaction at 100 MeV. The energy spectrum is measured up to 4.6 MeV and angular distributions corresponding different excitation regions are reported for first time. comparison between data theoretical predictions, including pairing correlation effects, shows existence ${p}_{1/2}$ resonance $0.45\ifmmode\pm\else\textpm\fi{}0.03\text{ }\text{...
The combination of γ-ray spectroscopy and charged-particle is a powerful tool for the study nuclear reactions with beams nuclei far from stability. This paper presents new silicon detector array, SHARC, Silicon Highly-segmented Array Reactions Coulex. array used at radioactive-ion-beam facility TRIUMF (Canada), in conjunction TIGRESS spectrometer, built custom Si-strip detectors utilising fully digital readout. SHARC has more than 50% efficiency, approximately 1000-strip segmentation,...
In Wolf-Rayet and asymptotic giant branch (AGB) stars, the (26g)Al(p,γ)(27)Si reaction is expected to govern destruction of cosmic γ-ray emitting nucleus (26)Al. The rate this reaction, however, highly uncertain due unknown properties key resonances in temperature regime hydrogen burning. We present a high-resolution inverse kinematic study (26g)Al(d,p)(27)Al as method for constraining strengths astrophysical reaction. particular, results indicate that resonance at E(r)=127 keV (27)Si...
The level structure of (22)Mg has been studied with high-sensitivity gamma-ray spectroscopy techniques. A complete scheme is derived incorporating all subthreshold states and levels in the energy region relevant for novae burning. excitation most important astrophysical resonance measured improved accuracy found to differ from previous values. Combining present result a recent measurement this state leads mass excess -400.5(13) keV.
The largest nuclear physics uncertainty in studies of gamma-ray emission from novae arises the $^{18}\mathrm{F}(p,\ensuremath{\alpha})^{15}\mathrm{O}$ reaction rate that affects abundance $^{18}\mathrm{F}$. Direct measurements have been made $^{18}\mathrm{F}(p,p)^{18}\mathrm{F}$ and differential cross sections energy range $0.6\ensuremath{\leqslant}{E}_{\mathrm{c}.\mathrm{m}.}\ensuremath{\leqslant}1.6$ MeV. Several resonances observed both measurements, with simultaneous $R$-matrix fits used...
We report a high-statistics measurement of the $L/K$ orbital electron capture ratio in $^{7}\mathrm{Be}$ embedded cryogenic Ta. The thin Ta film formed part high-resolution superconducting tunnel junction radiation detector that was used to identify signals from different decay channels. measured 0.070(7) is significantly larger than only previous this quantity and theoretical predictions include in-medium effects. This value uniquely sensitive probe 1s 2s overlaps with nucleus relevance...
Measurements of the elastic scattering cross section $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$ are important in order to improve constraints on theoretical models $^{4}\mathrm{He}(^{3}\mathrm{He},\ensuremath{\gamma})^{7}\mathrm{Be}$, a key reaction Big Bang nucleosynthesis solar neutrino production. The astrophysical $S$ factor for this is significant source uncertainty standard-solar-model prediction $^{7}\mathrm{Be}$ $^{8}\mathrm{B}$ fluxes. measurements reported literature do not extend low...
The ${}^{17}$O($p,\phantom{\rule{-0.16em}{0ex}}\ensuremath{\gamma}$)${}^{18}$F reaction plays an important role in hydrogen-burning nucleosynthesis. Conflicting values for the low-energy behavior of its cross section exist literature. We present direct measurements astrophysical $S$ factor at center-of-mass energies between 250 and 500 keV. These were conducted inverse kinematics DRAGON recoil separator.
We present the first direct measurement of an astrophysical reaction using a radioactive beam isomeric nuclei. In particular, we have measured strength key 447-keV resonance in ^{26m}Al(p,γ)^{27}Si to be 432_{-226}^{+146} meV and find that this dominates thermally averaged rate for temperatures between 0.3 2.5 GK. This work represents critical development resolving one longest standing issues nuclear astrophysics research, relating proton capture reactions on excited quantum levels, offers...
The elastic-scattering, neutron transfer and projectile break-up channels have been studied for the reaction 6He + 64Zn at energies around Coulomb barrier. results show a very large cross-section corresponding to largest fraction of total cross-section. No evidence threshold anomaly emerged from elastic-scattering optical-model analysis.
A multichannel R-matrix formalism was used to fit $^{21}\mathrm{Na}+$ p resonant elastic and inelastic scattering data taken at the TRIUMF UK detector array facility TRIUMF-ISAC. Five resonances were observed corresponding states in $^{22}\mathrm{Mg}$ above proton threshold. Four of these corresponded seen previous transfer reaction studies where firm spin-parity assignments could not be made. One new resonance, previously unobserved any reaction, also seen. Where possible, resonance...
The Doppler-shift attenuation method was applied to measure the lifetime of 4.03 MeV state in $^{19}\mathrm{Ne}$. By utilizing a $^{3}\mathrm{He}$-implanted Au foil as target, populated using $^{20}\mathrm{Ne}$($^{3}\mathrm{He}$, $\ensuremath{\alpha}$)$^{19}\mathrm{Ne}$ reaction inverse kinematics at $^{20}\mathrm{Ne}$ beam energy 34 MeV. De-excitation \ensuremath{\gamma} rays were detected coincidence with \ensuremath{\alpha} particles. At 1\ensuremath{\sigma} level, determined be...
For low energy reaction studies involving radioactive ion beams, the experimental yields are generally small due to intensity of beams. this reason, stacked target technique has been often used measure excitation functions. This offers considerable advantages since cross-section at several energies can be simultaneously measured. In a further effort increase yields, thick targets also employed. The main disadvantage method is degradation beam quality as it passes through stack statistical...
This paper presents values of complete fusion cross sections deduced from activation measurements for the reactions $\phantom{\rule{0.16em}{0ex}}^{6}\mathrm{Li}+\phantom{\rule{0.16em}{0ex}}^{120}\mathrm{Sn}$ and $\phantom{\rule{0.16em}{0ex}}^{7}\mathrm{Li}+\phantom{\rule{0.16em}{0ex}}^{119}\mathrm{Sn}$, a projectile energy range 17.5 to 28 MeV in center-of-mass system. A new deconvolution analysis technique is used link basic data actual excitation function. The above barrier are suppressed...
Background: Globular clusters are known to exhibit anomalous abundance trends such as the sodium-oxygen anticorrelation. This trend is thought arise via pollution of cluster interstellar medium from a previous generation stars. Intermediate-mass asymptotic giant branch stars undergoing hot bottom burning (HBB) prime candidate for producing sodium-rich oxygen-poor material, and then expelling this material strong stellar winds. The amount $^{23}\mathrm{Na}$ produced in environment has been...