C. J. Griffin
A5039597887- Nuclear physics research studies
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
- Quantum Chromodynamics and Particle Interactions
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Advanced Chemical Physics Studies
- Radiation Detection and Scintillator Technologies
- Semiconductor materials and devices
- Neutrino Physics Research
- Quantum, superfluid, helium dynamics
- Radiopharmaceutical Chemistry and Applications
- Boron Compounds in Chemistry
- Silicon and Solar Cell Technologies
- Hydrogen Storage and Materials
- Electronic Packaging and Soldering Technologies
- Copper Interconnects and Reliability
- Gamma-ray bursts and supernovae
- X-ray Diffraction in Crystallography
- X-ray Spectroscopy and Fluorescence Analysis
TRIUMF
2020-2025
University of Edinburgh
2015-2025
University of Brighton
2016-2020
Australian National University
2019
Sungkyunkwan University
2016
RIKEN Nishina Center
2016
Osaka University
2016
Neutron-induced reaction cross sections of short-lived nuclei are imperative to understand the origin heavy elements in stellar nucleosynthesis and for societal applications, but their measurement is extremely complicated due radioactivity targets involved. One way overcoming this issue combine surrogate reactions with unique possibilities offered by heavy-ion storage rings. In work, we describe first surrogate-reaction experiment inverse kinematics, which successfully conducted at...
The probabilities for γ-ray and particle emission as a function of the excitation energy decaying nucleus are valuable observables constraining ingredients models that describe deexcitation nuclei near threshold. These essential in nuclear astrophysics applications. In this paper, we have first time simultaneously measured neutron <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Pb</a:mi><a:mprescripts/><a:none/><a:mn>208</a:mn></a:mmultiscripts></a:math>....
We report the application of new elimination Rutherford elastic scattering technique for measurement proton-induced reaction cross sections utilizing stored ions decelerated to astrophysical energies. This approach results in a background reduction factor about 1 order magnitude, enabling first (p, n) section storage ring. Here, channels ^{124}Xe(p,n) and ^{124}Xe(p,γ) have been studied just above neutron threshold energy. The data provide valuable constraints Hauser-Feshbach theory...
The β-decay half-lives of 94 neutron-rich nuclei ^{144-151}Cs, ^{146-154}Ba, ^{148-156}La, ^{150-158}Ce, ^{153-160}Pr, ^{156-162}Nd, ^{159-163}Pm, ^{160-166}Sm, ^{161-168}Eu, ^{165-170}Gd, ^{166-172}Tb, ^{169-173}Dy, ^{172-175}Ho, and two isomeric states ^{174m}Er, ^{172m}Dy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops are observed neutron-number N=97 for _{58}Ce, _{59}Pr, _{60}Nd, _{62}Sm, N=105...
The Advanced Implantation Detector Array (AIDA) is a state-of-the-art detector system for the measurement of decay properties exotic nuclei at fragmentation/fission facilities. Built around stacks up to eight 8cm×8cm, 128 × strip (16384 pixels) or four 24cm×8cm, 384 (49152 double sided silicon detectors, positions both implanted ions and their subsequent products can be measured sub-mm precision. large number pixels per provide implant-decay correlations implantation rates ∼kHz. To process...
The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu β decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} in firmly established. branching E2/M1 mixing ratios for transitions deexciting measured, allowing extraction relative B(E2) values. In particular, 2_{3}^{+}→0_{2}^{+} 2_{3}^{+}→4_{1}^{+} observed first time. results show excellent agreement with new microscopic large-scale shell-model...
The conceptual design of the BRIKEN neutron detector at radioactive ion beam factory (RIBF) RIKEN Nishina Center is reported. setup a complex system aimed detecting heavy-ion implants, β particles, γ rays and β-delayed neutrons. whole includes Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors up to 166 3He-filled counters embedded in high-density polyethylene moderator. quite due large number different types 3He-tubes involved additional constraints introduced by...
Theoretical models of β-delayed neutron emission are used as crucial inputs in r-process calculations. Benchmarking the predictions these is a challenge due to lack currently available experimental data. In this work probabilities 33 nuclides important mass regions south and south-west 132Sn presented, 16 for first time. The measurements were performed at RIKEN using Advanced Implantation Detector Array (AIDA) BRIKEN detector array. P1n values presented constrain theoretical region,...
This Letter reports on the first cross-section measurements for Sr94(α,n)Zr97 and Kr86(α,n)Sr89 reactions. In particular, our measurement of is weak r-process reaction cross section obtained using a radioactive ion beam. experiment was enabled by use novel solid helium targets, comprised silicon thin films with high incorporation via sputtering technique. Yield were performed at center-of-mass energies 10.4 9.0 MeV reaction, 9.9 Sr94(α,n)Zr97, extending into respective Gamow energy windows...
Abstract We present the discovery of a new isotope 98Sn beyond double magic N = Z 50 nucleus 100Sn. was identified among projectile-fragmentation products 124Xe beam at 345 MeV/nucleon RI Beam Factory, RIKEN, Japan. Additionally, we have confirmed production 96In and 94Cd, previously reported as isotopes RIKEN. These highly proton-rich nuclei were separated using large-acceptance two-stage separator BigRIPS. Furthermore, determined cross sections its neighboring nuclei. experimental values...
We present the first nuclear cross-section measurements of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mo stretchy="false">(</a:mo><a:mi mathvariant="normal">p</a:mi><a:mo>,</a:mo><a:mi>γ</a:mi><a:mo stretchy="false">)</a:mo></a:mrow></a:math> and (p,n) reactions on <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"...
Neutron emission probabilities and half-lives of 37 <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>β</a:mi></a:mrow></a:math>-delayed neutron emitters from <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mmultiscripts><c:mrow><c:mi>Ni</c:mi></c:mrow><c:mprescripts/><c:none/><c:mrow><c:mn>75</c:mn></c:mrow></c:mmultiscripts></c:mrow></c:math> to <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
Abstract The β -delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using Advanced Implantation Detector Array (AIDA) BRIKEN neutron detector array. existing -decay half-life ( T 1/2 ) database was significantly increased toward more isotopes, uncertainties previously values decreased. new data not only constrain theoretical predictions half-lives probabilities, but also allow probing mechanisms...
The $\ensuremath{\beta}$-delayed one- and two-neutron emission probabilities (${P}_{1n}$ ${P}_{2n}$) of 20 neutron-rich nuclei with $N\ensuremath{\ge}82$ have been measured at the RIBF facility RIKEN Nishina Center. ${P}_{1n}$ $^{130,131}\mathrm{Ag}$, $^{133,134}\mathrm{Cd}$, $^{135,136}\mathrm{In}$, $^{138,139}\mathrm{Sn}$ were determined for first time, stringent upper limits placed on ${P}_{2n}$ nearly all cases. ($\ensuremath{\beta}2n$) was unambiguously identified in $^{133}\mathrm{Cd}$...
The level structure of 172Dy has been investigated for the first time by means decay spectroscopy following in-flight fission a 238U beam. A long-lived isomeric state with T1/2=0.71(5)s and Kπ=8− identified at 1278 keV, which decays to ground-state γ-vibrational bands through hindered electromagnetic transitions, as well daughter nucleus 172Ho via allowed β decays. robust nature isomer rotational band reveals an axially-symmetric this nucleus. Meanwhile, levels have unusually low excitation...
A detailed study of the structure doubly mid-shell nucleus Dy104166170 has been carried out, following isomeric and β decay. We have measured yrast band up to spin-parity Jπ=6+ state, K=2 γ-vibration 5+ a low-lying negative-parity based on 2− state that could be candidate for lowest energy octupole vibration within this nucleus, Kπ=6+ two quasi-particle isomer. This was determined an excitation 1643.91(23) keV half life 0.99(4) μs, with reduced hindrance its decay ground-state order...
The nuclear two-photon or double-gamma (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>2</a:mn><a:mi>γ</a:mi></a:math>) decay is a second-order electromagnetic process whereby nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mn>2</c:mn><c:mi>γ</c:mi></c:math> rate low-energy regime below electron-positron pair-creation threshold, we combined...
The cross-shell excited states of $^{34}\mathrm{Si}$ have been investigated via $\ensuremath{\beta}$ decays the ${4}^{\ensuremath{-}}$ ground state and ${1}^{+}$ isomeric $^{34}\mathrm{Al}$. Since valence protons neutrons occupy different major shells in as well intruder $^{34}\mathrm{Al}$, levels are populated allowed decays. Spin assignments to such were established through $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ angular correlation analysis for negative-parity with...
An ambitious program to measure decay properties, primarily β-delayed neutron emission probabilities and half-lives, for a significant number of nuclei near or on the path rapid capture process, has been launched at RIKEN Nishina Center.We give here an overview status project.
$\ensuremath{\beta}$-delayed one-neutron and two-neutron branching ratios $({P}_{1n}$ ${P}_{2n})$ have been measured in the decay of $A=84$ to 87 Ga isotopes at Radioactive-Isotope Beam Factory (RIBF) RIKEN Nishina Center using a high-efficiency array $^{3}\mathrm{He}$ neutron counters (BRIKEN). Two-neutron emission was observed $^{84,85,87}\mathrm{Ga}$ for first time were be ${P}_{2n}=1.6(2)%,1.3(2)%$, $10.2{(28)}_{\mathrm{stat}}{(5)}_{\mathrm{sys}}%$, respectively. One-neutron ratio...
Bound-state β − -decay is an exotic decay mode that produces temperature-dependent stability in nuclei. A striking example 205 Tl, part because of its impact on the Pb/ 204 Pb cosmochronometer—a short-lived ra-dionuclide clock can provide unique constraints s process material early solar system. The bound-state Tl was measured at GSI, where fully stripped 81+ ions were produced and stored Experimental Storage Ring. Decay occurred during storage producing increased daughters with time. This...
The neutron-rich dysprosium isotopes 168Dy102 and 169Dy103 have been investigated using the EURICA γ-ray spectrometer, following production via in-flight fission of a high-intensity uranium beam in conjunction with isotope separation through BigRIPS separator at RIBF RIKEN Nishina Center. For 168Dy, previously unreported isomer half-life 0.57(7) μs has identified an excitation energy 1378 keV, its presence affirmed independently γ-γ-γ coincidence data taken Gammasphere two-proton transfer...
Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for first time at Radioactive Isotope Beam Factory RIKEN Nishina Center. New millisecond isomers have identified low excitation energies, 985.3(19) keV in Tl213 and 874(5) Tl215. The measured half-lives 1.34(5) ms 3.0(3) Tl215 suggest spins parities 11/2− with single proton-hole configuration πh11/2 as leading component. They are populated via E1 transitions by decay higher-lying isomeric states...