A5030759641- Nuclear physics research studies
- Atomic and Molecular Physics
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Ultrasonics and Acoustic Wave Propagation
- Nuclear Physics and Applications
- Structural Health Monitoring Techniques
- Advanced Condensed Matter Physics
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Cold Atom Physics and Bose-Einstein Condensates
- Astronomical and nuclear sciences
- Geophysical Methods and Applications
- Particle accelerators and beam dynamics
- Non-Destructive Testing Techniques
- Advanced Frequency and Time Standards
- Physics of Superconductivity and Magnetism
- Mass Spectrometry Techniques and Applications
- Magnetic properties of thin films
- Neutrino Physics Research
- Advancements in Battery Materials
- Particle physics theoretical and experimental studies
- NMR spectroscopy and applications
- Muon and positron interactions and applications
- Thermography and Photoacoustic Techniques
Cardiff University
2013-2024
University of New Mexico
2023-2024
TRIUMF
2014-2023
University of Liverpool
1994-2023
Vancouver Biotech (Canada)
2018-2020
Michelin (United States)
2016
University of Manitoba
2012-2014
University of British Columbia
2011-2012
National Superconducting Cyclotron Laboratory
2012
Michigan State University
2012
Classifying the type of damage occurring within a structure using structural health monitoring system can allow end user to assess what kind repairs, if any, that component requires. This paper investigates use acoustic emission (AE) locate and classify in composite, carbon fibre panel during buckling. The was first located bespoke location algorithm developed at Cardiff University, called delta-T mapping. Signals identified as coming from regions were then analysed three AE classification...
The nuclear charge radius of 11Li has been determined for the first time by high-precision laser spectroscopy. On-line measurements at TRIUMF-ISAC yielded a 7Li-11Li isotope shift (IS) 25 101.23(13) MHz Doppler-free [FORMULA: SEE TEXT]transition. IS accuracy all other bound Li isotopes was also improved. Differences from calculated mass-based yield values change in along chain. decreases monotonically 6Li to 9Li, and then increases 2.217(35) 2.467(37) fm 11Li. This is compared various...
An easy to use, fast apply, cost-effective, and very accurate non-destructive testing (NDT) technique for damage localisation in complex structures is key the uptake of structural health monitoring systems (SHM). Acoustic emission (AE) a viable that can be used SHM one most attractive features ability locate AE sources. The time arrival (TOA) traditionally sources, relies on assumption constant wave speed within material uninterrupted propagation path between source sensor. In geometries...
We present precision Penning trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity neutron number N=32. Using TITAN system, 51K was measured for first time, (51,52)Ca values were improved significantly. The new show a dramatic increase binding energy compared to those reported atomic evaluation. In particular, 52Ca is more bound by 1.74 MeV, behavior with deviates substantially from tabulated values. An increased predicted recently based on calculations that...
TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing charge state short-lived nuclides prior actual determination in Penning trap. Recent developments around TITAN's breeder, electron beam ion trap, form basis several successful experiments on radioactive isotopes with half-lives as low 65 ms states 22+.
In order to overcome the difficulties in applying traditional time-of-arrival techniques for locating acoustic emission events complex structures and materials, a technique termed ‘Delta-t mapping’ was developed. This article presents significant improvement on this, which identifying precise arrival time of an signal are addressed by incorporating Akaike information criteria. The performance arrival, Delta-t mapping criteria is assessed artificial sources, fatigue damage impact aluminium...
We report the observation of weak magnetism in superlattices LaAlO3/SrTiO3 using beta-detected nuclear magnetic resonance. The spin lattice relaxation rate 8 Li with a spacer layers and 6 unit cells LaAlO3 exhibits strong peak near ~35 K, whereas no such is observed superlattice layer thickness 3 cells. attribute temperature dependence to slowing down weakly coupled electronic moments at interface. These results show that interface depends strongly on layer, minimal ~4-6 required for...
Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using TITAN facility at TRIUMF. Compared to singly this provides an improvement in experimental precision that scales charge state q. Neutron-deficient Rb isotopes bred electron beam ion q=8-12+ prior injection into trap. In combination Ramsey excitation scheme, unique setup creating low energy, ions a radioactive opens door unrivaled gains 1-2 orders magnitude. The method...
Changes in the mean-square nuclear charge radii along lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear light elements are high interest due to appearance halo phenomenon this region chart. During past years we have developed new laser spectroscopic approach determine isotopes which combines sensitivity, speed, accuracy measure extremely small field an 8 ms lifetime with production rates on...
We demonstrate that zero-field $\beta$-detected nuclear quadrupole resonance and spin relaxation of low energy $^8$Li can be used as a sensitive local probe structural phase transitions near surface. find the transition surface SrTiO$_3$ single crystal occurs at $T_c \sim 150$ K, i.e., 45 K higher than $T^{bulk}_c$, tetragonal domains formed below $T_c$ are randomly oriented.
A high-precision Penning trap mass measurement of the exotic $^{8}\mathrm{He}$ nuclide (${T}_{1/2}=119\text{ }\text{ }\mathrm{ms}$) has been carried out resulting in a reduction uncertainty halo binding energy by over an order magnitude. The new mass, determined with relative $9.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ ($\ensuremath{\delta}m=690\text{ }\mathrm{eV}$) is 13 keV less bound than previously accepted value. great relevance for recent charge-radius [P. Mueller et...
We report a direct measurement of the ${Q}_{\ensuremath{\beta}\ensuremath{\beta}}$ value neutrinoless double-$\ensuremath{\beta}$-decay candidate ${}^{48}\mathrm{Ca}$ at TITAN Penning-trap mass spectrometer, with result that ${Q}_{\ensuremath{\beta}\ensuremath{\beta}}=4267.98(32)\phantom{\rule{0.28em}{0ex}}\text{keV}$. measured masses both mother and daughter nuclides, in latter case found 1 keV deviation from literature value. In addition to value, we also present results new calculation...
Abstract Objective The National Institutes of Health (NIH) HEAL Initiative is making data findable, accessible, interoperable, and reusable (FAIR) to maximize the value unprecedented federal investment in pain opioid-use disorder research. This involves standardizing use common elements (CDE) for clinical Methods work describes process selection, processing, harmonization, design constraints CDE across a opioid trials network. Results network alignment allowed incorporation newer standards...
The neutron-rich mass region around $A\approx100$ presents challenges for modeling the astrophysical $r$-process because of rapid shape transitions. We report on measurements using TITAN Penning trap at TRIUMF-ISAC to attain more reliable theoretical predictions nucleosynthesis paths in this region. A new approach highly charged ($q=15+$) ions has been applied which considerably saves measurement time and preserves accuracy. New $^{94,97,98}$Rb $^{94,97-99}$Sr have uncertainties less than 4...
Collinear laser spectroscopy was performed on the nuclear ground states of neutron-deficient isotopes $^{206,205,204}\mathrm{Fr}$. A new technique developed to suppress hyperfine pumping in collinear atoms. This involved high-frequency intensity modulation narrow-linewidth light using fast-switching electro-optical modulators. The ground-state spins $^{206,205,204}\mathrm{Fr}$ were determined be 3, $9/2$, and respectively. Both changes mean-squared charge radii magnetic dipole moments...
We have measured the hyperfine splitting of 7P_{1/2} state at 100 ppm level in Fr isotopes (^{206g,206m,207,209,213,221}Fr) near closed neutron shell (N=126 ^{213}Fr). The measurements five and a nuclear isomeric francium, combined with previous determinations 7S_{1/2} splittings, reveal spatial distribution magnetization, i.e., Bohr-Weisskopf effect. compare our results simple model consisting unpaired single valence nucleons orbiting spherical nucleus, find good agreement over range...
Acoustic emission is widely used for mechanical diagnostics and to characterise damage in composite materials. Distinction between different mechanisms still one of the major challenges remains an unresolved issue. The objective cluster analysis separate acoustic data set into multiple classes that reflect sources. This article concerned with implementation unsupervised clustering techniques classify transients from a carbon fibre laminate buckling test. A new approach signal feature...
Collinear-laser spectroscopy with the bunched-beams technique was used for study of neutron deficient Rb isotopes, out to $^{74}\mathrm{Rb}$ ($N=Z=37$) at TRIUMF. The measured hyperfine coupling constants $^{76,78m}\mathrm{Rb}$ were in agreement literature values. nuclear spin $^{75}\mathrm{Rb}$ confirmed be $I=3/2$, and its first time. mean-square charge radius determined This result has improved isospin symmetry breaking correction term calculate $\mathcal{F}t$ value, implications tests...
Recent research into damage detection methodologies, embedded sensors, wireless data transmission and energy harvesting in aerospace environments has meant that autonomous structural health monitoring (SHM) systems are becoming a real possibility. The most promising system would utilise sensor nodes able to make decisions on communicate this wirelessly central base station. Although such shows great potential both passive active techniques exist for detecting structures, powering sensors...
We report the NMR Knight shift and spin-lattice relaxation of $^{8}\mathrm{Li}{}^{+}$ implanted $\ensuremath{\sim}100$ nm into single crystals semimetallic Sb, Bi, topologically insulating ${\mathrm{Bi}}_{0.9}{\mathrm{Sb}}_{0.1}$. find small negative shifts (of order 100 ppm) in all three. In insulator, is nearly temperature independent, while Bi Sb it becomes more at low without following bulk susceptibility, suggesting two distinct dependent contributions, possibly from orbital spin...
We present lifetime measurements of the ${7D}_{3/2}$ and ${7D}_{5/2}$ levels Fr. use a time-correlated single-photon counting technique on sample ${}^{210}\mathrm{Fr}$ atoms confined cooled in magneto-optical trap. The upper state ${7P}_{3/2}$ trapping transition serves as resonant intermediate level for two-photon excitation $7D$ states. A probe laser provides second step excitation, we detect decay atomic fluorescence. Our help extend knowledge this class wave functions which correlation...
A high-precision branching ratio measurement for the superallowed beta+ decay of 62Ga was performed at Isotope Separator and Accelerator radioactive ion beam facility. Nineteen gamma rays emitted following were identified, establishing dominant to be (99.861+/-0.011)%. Combined with recent half-life Q-value measurements, this yields a ft value 3075.6+/-1.4 s decay. These results demonstrate feasibility measurements in A>or=62 mass region provide first stringent tests large...