Publications (53)
Spectroscopic study of Ca from the $β^-$ decay of K
J. K. Smith, A. B. Garnsworthy, J. L. Pore +30
The $β^-$ decay of K to Ca is an appropriate mechanism for benchmarking interactions spanning the and shells, but current knowledge of the $β^-$-decay sch…
Decay Spectroscopy of Eu: Quasiparticle Configurations of Excited States and Structure of = Band-heads in Gd
D. Yates, R. Kruecken, I. Dillmann +45
\noindent \textbf{Background:} Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-pr…
Single neutron transfer on 23Ne and its relevance forthepathway ofnucleosynthesis in astrophysical X-ray bursts
G. Lotay, J. Henderson, W. N. Catford +32
We present new experimental measurements of resonance strengths in the astrophysical 23Al(p, γ)24Si reaction, constraining the pathway of nucleosynthesis beyond 22Mg in X-ray burs…
Detailed spectroscopy of Ca: A study of the $β^-$ decay of K
J. L. Pore, C. Andreoiu, J. K. Smith +33
We report on high-statistics data from the $β^-$ decay of the K = 2 ground state taken with the GRIFFIN spectrometer located at the TRIUMF-ISAC facility. In tota…
Precise branching ratio measurements in Ne beta decay and fundamental tests of the weak interaction
B. M. Rebeiro, S. Triambak, P. Z. Mabika +25
We used the 8 -ray spectrometer at the TRIUMF-ISAC radiocative ion beam facility to obtain high-precision branching ratios for Ne $β^+$ decay to excited states in $…
Improved measurement of the E0 transition strength for Se using the SPICE spectrometer
J. Smallcombe, A. B. Garnsworthy, W. Korten +22
The selenium isotopes lie at the heart of a tumultuous region of the nuclear chart where shape coexistence effects grapple with neutron-proton pairing correlations, triaxiality, an…
Observation of excited states in Mg sheds light on nuclear forces and shell evolution
J. S. Randhawa, R. Kanungo, M. Holl +35
The exotic Borromean nucleus Mg with = 8, located at the proton drip-line provides a unique testing ground for nuclear forces and the evolution of shell structure in the…
Absence of Low-Energy Shape Coexistence in Ge: The Nonobservation of a Proposed Excited 0 Level at 639 keV
F. H. Garcia, C. Andreoiu, G. C. Ball +28
The Ge structure was investigated in a high-statistics -decay experiment of Ga using the GRIFFIN spectrometer at TRIUMF-ISAC through , -, - and…
Excitation Energies and Spins of the Yrast Superdeformed Band in ^{191}Hg
S. Siem, P. Reiter, T. L. Khoo +23
The excitation energies and spins of the levels in the yrast superdeformed band of Hg have been determined from two single-step transitions and the quasi-continuum spe…
Single-Particle Structure of Neutron-Rich Sr Isotopes Via d( 94,95,96 Sr, p) Reactions
S. Cruz, K. Wimmer, P. C. Bender +32
The region around neutron number N = 60 in the neutron-rich Sr and Zr nuclei is one of the most dramatic examples of a ground state shape transition from (near) spherical below N =…
Shape Coexistence and Mixing of Low-Lying States in Sr
S. Cruz, P. C. Bender, R. Krücken +32
The low energy excited states in Sr are amongst the most prominent examples of shape coexistence across the nuclear landscape. In this work, the neutron $[2s_{1/…
Direct measurement of Cu(,)Ni precludes a strong NiCu cycle in Type-I X-ray bursts
N. Bhathi, J. S. Randhawa, R. Kanungo +36
Model-observation comparisons of type-I X-ray bursts (XRBs) can reveal the properties of accreting neutron star systems, including the neutron star compactness. XRBs are powered by…
Decay Spectroscopy of Cd
Y. Saito, I. Dillmann, R. Krücken +42
Excited states of In populated following the -decay of Cd were experimentally studied with the GRIFFIN spectrometer at the ISAC facility of TRIUMF, Canada. A 48…
Shell evolution approaching the N=20 island of inversion: Structure of 29Mg
A. Matta, W. N. Catford, N. A. Orr +36
The "Island of Inversion" for neutron-rich nuclei in the vicinity of N=20 has become the testing ground par excellence for our understanding and modelling of shell evolution with i…
Decay spectroscopy of Sc and Sc to Ti
M. Bowry, C. E. Jones, A. B. Garnsworthy +10
The decay of the isomeric and ground state of Sc to the semi-magic nucleus Ti has been studied using a Ca beam delivered to the GRIFFIN -r…
Half-Lives of Neutron Rich Cd and In
R. Dunlop, C. E. Svensson, C. Andreoiu +40
The half-lives of isotopes around the shell closure are an important ingredient in astrophysical simulations and strongly influence the magnitude of the second -process a…
Lifetimes of low-lying excited states in Kr
J. Henderson, A. Chester, G. C. Ball +14
The evolution of nuclear magic numbers at extremes of isospin is a topic at the forefront of contemporary nuclear physics. is a prime example, with increasing experimental d…
Lifetime of 19Ne*(4.03 MeV)
R. Kanungo, T. K. Alexander, A. N. Andreyev +20
The Doppler-shift attenuation method was applied to measure the lifetime of the 4.03 MeV state in 19Ne. Utilizing a 3He-implanted Au foil as a target, the state was populated using…
Lifetimes of states in 19Ne above the 15 O + alpha breakup threshold
S. Mythili, B. Davids, T. K. Alexander +19
The 15O(alpha,gamma)19Ne reaction plays a role in the ignition of Type I x-ray bursts on accreting neutron stars. The lifetimes of states in 19Ne above the 15O + alpha threshold of…
First Evidence of Axial Shape Asymmetry and Configuration Coexistence in Zn: Suggestion for a Northern Extension of the Island of Inversion
M. Rocchini, P. E. Garrett, M. Zielinska +41
The excited states of Zn were investigated via -ray spectroscopy following Cu decay. By exploiting - angular correlation analysis, the …
Cross Sections of the Rb(p,Sr and Kr(p,Rb Reactions at Energies Characteristic of the Astrophysical Process
M. Williams, B. Davids, G. Lotay +22
We have measured the cross section of the Rb(p,Sr radiative capture reaction in inverse kinematics using a radioactive beam of Rb at incident energies of 2.…
Coulomb excitation of the , mirror pair
J. Henderson, G. Hackman, P. Ruotsalainen +23
Background: Electric-quadrupole () strengths relate to the underlying quadrupole deformation of a nucleus and present a challenge for many nuclear theories. Mirror nuclei in th…
Use of Bayesian Optimization to Understand the Structure of Nuclei
J. Hooker, J. Kovoor, K. L. Jones +41
Monte Carlo simulations are widely used in nuclear physics to model experimental systems. In cases where there are significant unknown quantities, such as energies of states, an it…
Ba and La structure from lifetime measurements
B. Olaizola, A. Babu, R. Umashankar +21
The occurrence of octupole shapes in even-mass neutron-rich Ba isotopes has been well established. However, the situation with the odd-mass Ba and odd or odd-odd La nuclei around t…
Testing microscopically derived descriptions of nuclear collectivity: Coulomb excitation of 22Mg
J. Henderson, G. Hackman, P. Ruotsalainen +24
Many-body nuclear theory utilizing microscopic or chiral potentials has developed to the point that collectivity might be dealt with in an {\it ab initio} framework without the use…
Intruder structures in Si and Al
J. Williams, G. Hackman, K. Starosta +31
We have studied Si and Al using C(Ne,2p) and C(Ne,p) fusion-evaporation reactions. In both cases, we observed significant population o…
Systematics of E2 strength in the sd-shell with the valence-space in-medium similarity renormalization group
S. R. Stroberg, J. Henderson, G. Hackman +3
Background: Recent developments in {\it ab initio} nuclear theory demonstrate promising results in medium- to heavy-mass nuclei. A particular challenge for many of the many-body me…
Shape coexistence in the neutron-deficient lead region: A systematic study of lifetimes in the even-even Hg with GRIFFIN
B. Olaizola, A. B. Garnsworthy, G. C. Ball +37
Lifetimes of and states, as well as some negative-parity and non-yrast states, in Hg were measured using electronic fast timing techniques with…
The GRIFFIN Data Acquisition System
A. B. Garnsworthy, C. J. Pearson, D. Bishop +10
Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new experimental facility for radioactive decay studies at the TRIUMF-ISAC laboratory. This article…
The nuclear force imprints revealed on the elastic scattering of protons with C
A. Kumar, R. Kanungo, A. Calci +26
How does nature hold together protons and neutrons to form the wide variety of complex nuclei in the universe? Describing many-nucleon systems from the fundamental theory of quantu…
High-Precision Branching Ratio Measurement and Spin Assignment Implications for Ga Superallowed Decay
A. D. MacLean, A. T. Laffoley, C. E. Svensson +48
A high-precision branching ratio measurement for the superallowed Fermi $β^{+}$ emitter Ga was performed with the Gamma-Ray Infrastructure for Fundamental Investigations of…
High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents
S. Triambak, P. Finlay, C. S. Sumithrarachchi +21
We report a precise determination of the 19Ne half-life to be s. This result disagrees with the most recent precision measurements and is important for…
Cross-shell excited configurations in the structure of 34Si
R. S. Lubna, A. B. Garnsworthy, Vandana Tripathi +23
The cross-shell excited states of Si have been investigated via -decays of the ground state and the isomeric state of Al. Since the valence protons an…
First application of Markov Chain Monte Carlo-based Bayesian data analysis to the Doppler-Shift Attenuation Method
L. J. Sun, C. Fry, B. Davids +31
Motivated primarily by the large uncertainties in the thermonuclear rate of the PS reaction that limit our understanding of classical novae, we carried out life…
Characteristics of GRIFFIN high-purity germanium clover detectors
U. Rizwan, A. B. Garnsworthy, C. Andreoiu +11
The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new experimental facility for radioactive decay studies at the TRIUMF-ISAC laboratory. The perf…
Isospin symmetry in values: Coulomb excitation study of Mg
P. Ruotsalainen, J. Henderson, G. Hackman +37
The ~=~ nucleus Mg has been studied by Coulomb excitation on Pt and Pd targets. A 205.6(1)-keV -ray transition resulting from th…
Shell evolution approaching the N=20 island of inversion: structure of 26Na
G. L. Wilson, W. N. Catford, N. A. Orr +37
The levels in 26Na with single particle character have been observed for the first time using the d(25Na,p gamma) reaction at 5 MeV/nucleon. The measured excitation energies and th…
Two-neutron transfer reaction mechanisms in C(He,He)C using a realistic three-body He model
D. Smalley, F. Sarazin, F. M. Nunes +33
The reaction mechanisms of the two-neutron transfer reaction C(He,He) have been studied at 30 MeV at the TRIUMF ISAC-II facility using the SHARC charged-particle det…
Coulomb Excitation of Sr and the limits of the island of deformation
R. Russell, J. Heery, J. Henderson +33
The region of has long been associated with strongly deformed nuclear configurations. The presence of this strong deformation was recently confirmed through…
Reorientation-effect measurement of the first 2 state in C: confirmation of oblate deformation
M. Kumar Raju, J. N. Orce, P. Navratil +6
A Coulomb-excitation reorientation-effect measurement using the TIGRESS ray spectrometer at the TRIUMF/ISAC II facility has permitted the first determination of the $\langle 2…
Spectroscopy of Sc and ab initio calculations of strengths
A. B. Garnsworthy, M. Bowry, B. Olaizola +10
The GRIFFIN spectrometer at TRIUMF-ISAC has been used to study excited states and transitions in Sc following the -decay of Ca. Branching ratios were determined f…
First Direct Measurement of an Astrophysical p-Process Reaction Cross Section Using a Radioactive Ion Beam
G. Lotay, S. A. Gillespie, M. Williams +35
We have performed the first direct measurement of the 83Rb(p,g) radiative capture reaction cross section in inverse kinematics using a radioactive beam of 83Rb at incident energies…
and -delayed neutron decay of the nucleus In
R. Dunlop, C. E. Svensson, C. Andreoiu +26
The half-lives of three decaying states of In have been measured with the GRIFFIN -ray spectrometer at the TRIUMF-ISAC facility to be $T_{1/2}(1/2^-)=…
First direct measurement of Cu(p,)Ni: A step towards constraining the Ni-Cu cycle in the Cosmos
J. S. Randhawa, R. Kanungo, J. Refsgaard +34
Reactions on the proton-rich nuclides drive the nucleosynthesis in Core-Collapse Supernovae (CCSNe) and in X-ray bursts (XRBs). CCSNe eject the nucleosynthesis products to the inte…
High-Precision Half-life Measurement for the Superallowed Fermi $β^+$ Emitter Mg
M. R. Dunlop, C. E. Svensson, G. C. Ball +23
A high-precision half-life measurement for the superallowed Fermi $β^+$ emitter Mg was performed at the TRIUMF-ISAC facility using a 4 proportional gas counter. The res…
Single-particle structure in neutron-rich Sr isotopes approaching the N = 60 shape transition
S. Cruz, K. Wimmer, S. S. Bhattacharjee +33
Background: Neutron-rich nuclei around neutron number N = 60 show a dramatic shape transition from spherical ground states to prolate deformation in 98Sr and heavier nuclei. Purpos…
Identifying the spin trapped character of the Si isomeric state
J. Williams, G. Hackman, K. Starosta +30
The properties of a nanosecond isomer in Si, disputed in previous studies, depend on the evolution of proton and neutron shell gaps near the `island of inversion'. We have p…
Structure Studies of from the Be(d,p) reaction in inverse kinematics on a solid deuteron target
J. Kovoor, K. L. Jones, J. Hooker +42
The low-lying structure of Be has remained an enigma for decades. Despite numerous experimental and theoretical studies, large inconsistencies remain. Being both unbound, an…
In-beam internal conversion electron spectroscopy with the SPICE detector
M. Moukaddam, J. Smallcombe, L. J. Evitts +36
The SPectrometer for Internal Conversion Electrons (SPICE) has been commissioned for use in conjunction with the TIGRESS -ray spectrometer at TRIUMF's ISAC-II facility. SPICE f…
Measurement of Lifetimes in 23Mg
O. S. Kirsebom, P. Bender, A. Cheeseman +22
Several lifetimes in 23Mg have been determined for the first time using the Doppler-shift attenuation method. A Monte Carlo simulation code has been written to model the gamma-ray…
Proton inelastic scattering reveals deformation in He
M. Holl, R. Kanungo, Z. H. Sun +27
A measurement of proton inelastic scattering of He at ~MeV at TRIUMF shows a resonance at 3.54(6)~MeV with a width of 0.89(11)~MeV. The energy of the state is in good ag…
Investigation of the Excited States of Using the GRIFFIN Spectrometer at TRIUMF
N. K. Syeda, P. Spagnoletti, C. Andreoiu +43
The semi-magic isotopes display signs of shape coexistence in their excited states, which, in contrast to the spherical ground states, are defor…
The GRIFFIN Facility for Decay-Spectroscopy Studies at TRIUMF-ISAC
A. B. Garnsworthy, C. E. Svensson, M. Bowry +101
Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency -ray spectrometer designed for use in decay spectroscopy experiments with l…