P. M. Walker
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View article: Origin of the electric hexadecapole isomer in $^{93}$Mo
Origin of the electric hexadecapole isomer in $^{93}$Mo Open
We present a shell-model analysis of $^{93}$Mo to investigate the unusual behavior of its ${21/2}^+$ isomer -- a prominent candidate for nuclear excitation by electronic capture. This state is unique as its decay is dominated by a slow ele…
View article: Quantifying neutron-proton interactions in $N=51$ isotones: from NEEC candidate $^{93}$Mo to $^{99}$Cd
Quantifying neutron-proton interactions in $N=51$ isotones: from NEEC candidate $^{93}$Mo to $^{99}$Cd Open
We present a shell-model analysis of $N=51$ isotones, $^{93}$Mo, $^{95}$Ru, $^{97}$Pd, and $^{99}$Cd, to quantify the role of neutron-proton interactions in shaping the location and half-life of isomeric states. The study is motivated by t…
View article: First <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-delayed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math>-ray spectroscopy of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Nb</mml:mi><mml:mprescripts/><mml:none/><mml:mn>109</mml:mn></mml:mmultiscripts></mml:math>: Single-quasiparticle states with prolate shape in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Mo</mml:mi><mml:mprescripts/><mml:none/><mml:mn>109</mml:mn></mml:mmultiscripts></mml:math>
First -delayed -ray spectroscopy of : Single-quasiparticle states with prolate shape in Open
11 pages, 7 figures, 6 tables
View article: Direct observation of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> decay from a high-spin long-lived isomer in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ta</mml:mi><mml:mprescripts/><mml:none/><mml:mn>187</mml:mn></mml:mmultiscripts></mml:math>
Direct observation of and decay from a high-spin long-lived isomer in Open
$^{187}$Ta ($Z=73$, $N=114$) is located in the neutron-rich $A \\approx 190$\nregion where a prolate-to-oblate shape transition via triaxial softness is\npredicted to take place. A preceding work on the $K^{\\pi} = (25/2^-)$ isomer\nand a …
View article: Measurement of the Isolated Nuclear Two-Photon Decay in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mmultiscripts> <mml:mrow> <mml:mi>Ge</mml:mi> </mml:mrow> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>72</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:mrow> </mml:math>
Measurement of the Isolated Nuclear Two-Photon Decay in Open
The nuclear two-photon or double-gamma ( 2 γ ) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the 2 γ decay rate in the low-ener…
View article: Nuclear isomers
Nuclear isomers Open
View article: K isomers in atomic nuclei
K isomers in atomic nuclei Open
View article: Measurement of the Isolated Nuclear Two-Photon Decay in $^{72}\mathrm{Ge}$
Measurement of the Isolated Nuclear Two-Photon Decay in $^{72}\mathrm{Ge}$ Open
The nuclear two-photon or double-gamma ($2γ$) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the $2γ$ decay rate in the low-energy r…
View article: Interpretation of metastable states in the $$N>70$$ Zr region
Interpretation of metastable states in the $$N>70$$ Zr region Open
View article: Double-up for single-ion masses
Double-up for single-ion masses Open
View article: Executive Summary of the Topical Program: Nuclear Isomers in the Era of FRIB
Executive Summary of the Topical Program: Nuclear Isomers in the Era of FRIB Open
We report on the Facility for Rare Isotope Beams (FRIB) Theory Alliance topical program "Nuclear Isomers in the Era of FRIB". We outline the many ways isomers influence and contribute to nuclear science and technology, especially in the fo…
View article: Inelastic excitation of new high-spin yrast isomers in 180Ta
Inelastic excitation of new high-spin yrast isomers in 180Ta Open
For the first time, six-quasiparticle isomers have been observed in the meta-stable nucleus 18073Ta107. Two new high-spin isomers were populated following deep-inelastic reactions with a pulsed 23892U beam incident on a thick 18072Hf targe…
View article: Yrast three-quasiparticle K isomers in neutron-rich 181Hf
Yrast three-quasiparticle K isomers in neutron-rich 181Hf Open
New high-K orbitals have been identified in the neutron-rich 181Hf nucleus via one-neutron transfer from a pulsed 238U beam onto a stable 180Hf target. Yrast three-quasiparticle high-K isomers, with half-lives as long as 1.5 ms, have been …
View article: Identification of a high-spin isomer in Mo99
Identification of a high-spin isomer in Mo99 Open
A previously unreported isomer has been identified in Mo99 at an excitation energy of Ex=3010 keV, decaying with a half-life of T1/2=8(2) ns. The nucleus of interest was produced following fusion-fission reactions between a thick Al27 targ…
View article: High-spin, multiparticle isomers in Sb121,123
High-spin, multiparticle isomers in Sb121,123 Open
Isomers in near-spherical Z=51, antimony isotopes are reported here for the first time using fusion-fission reactions between Al27 and a pulsed Hf178 beam of energy, 1150 MeV. γ rays were observed from the decay of isomeric states with hal…
View article: New structures in 178Hf and coulomb excitation of isomers
New structures in 178Hf and coulomb excitation of isomers Open
A 985 MeV 178Hf beam was Coulomb excited by a 208Pb target at the ATLAS accelerator of Argonne National Laboratory. Gammasphere and the CHICO particle detector recorded particle-γ coincidence data. The aim was to populate and determine the…
View article: Precision Experiments with Heavy-ion Storage Rings
Precision Experiments with Heavy-ion Storage Rings Open
International audience
View article: High-spin states in 212Po above the α-decaying (18+) isomer
High-spin states in 212Po above the α-decaying (18+) isomer Open
View article: GANIL / SPIRAL - 2001-2007 - Achievements, Highlights and Perspectives
GANIL / SPIRAL - 2001-2007 - Achievements, Highlights and Perspectives Open
Since the early eighties, the intermediate energy ion beams of the GANIL facility and the associated equipments have played a pioneer role in the emergence of new fields in Nuclear Physics based on the production of exotic nuclei in unknow…
View article: Ground-state <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-decay spectroscopy of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ta</mml:mi><mml:mprescripts/><mml:none/><mml:mn>187</mml:mn></mml:mmultiscripts></mml:math>
Ground-state -decay spectroscopy of Open
We report beta-decay spectroscopy of the 187Ta ground state was performed at the KEK Isotope Separation System. β-delayed γ rays corresponding to the previously reported in-beam transitions were observed. The β-decay half-life o…
View article: First application of mass measurement with the Rare-RI Ring reveals the solar r-process abundance trend at A=122 and A=123
First application of mass measurement with the Rare-RI Ring reveals the solar r-process abundance trend at A=122 and A=123 Open
The Rare-RI Ring (R3) is a recently commissioned cyclotron-like storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of…
View article: First direct observation of isomeric decay in neutron-rich odd-odd <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ta</mml:mi><mml:mprescripts/><mml:none/><mml:mn>186</mml:mn></mml:mmultiscripts></mml:math>
First direct observation of isomeric decay in neutron-rich odd-odd Open
Deexcitation γ rays associated with an isomeric state of 186Ta were investigated. The isomers were produced in multinucleon transfer reactions between a 136Xe beam and a natural W target and were collected and separat…
View article: Development of a large-area timing and position-sensitive foil-MCP detector for mass measurements at the Rare-RI Ring in RIKEN
Development of a large-area timing and position-sensitive foil-MCP detector for mass measurements at the Rare-RI Ring in RIKEN Open
To achieve high precision and accuracy for mass measurements of exotic nuclei by Time-of-flight (TOF) methods: high-resolution beam-line magnetic-rigidity time-of-flight (B$ρ$-TOF) and in-ring isochronous mass spectrometry (IMS), a large-a…
View article: Discovery of a new 2.3 s isomer in the neutron-rich nucleus 174Tm
Discovery of a new 2.3 s isomer in the neutron-rich nucleus 174Tm Open
View article: Manifestation of the Berry phase in the atomic nucleus 213Pb
Manifestation of the Berry phase in the atomic nucleus 213Pb Open
View article: Beta decay of the axially asymmetric ground state of 192Re
Beta decay of the axially asymmetric ground state of 192Re Open
View article: Properties of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ta</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>187</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> Revealed through Isomeric Decay
Properties of Revealed through Isomeric Decay Open
Mass-separated ^{187}Ta_{114} in a high-spin isomeric state has been produced for the first time by multinucleon transfer reactions, employing an argon gas-stopping cell and laser ionization. Internal γ rays revealed a T_{1/2}=7.3±0.9 s is…
View article: Competition between Allowed and First-Forbidden <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math> Decay: The Case of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Hg</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>208</mml:mn></mml:mrow></mml:mmultiscripts><mml:mo stretchy="false">→</mml:mo><mml:mmultiscripts><mml:mrow><mml:mi>Tl</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>208</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
Competition between Allowed and First-Forbidden Decay: The Case of Open
The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions…
View article: Isomeric and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math>-decay spectroscopy of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Ho</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>173</mml:mn><mml:mo>,</mml:mo><mml:mn>174</mml:mn></mml:mrow></mml:mmultiscripts></mml:math>
Isomeric and -decay spectroscopy of Open
β-decay spectroscopy of 173,174Ho (Z = 67, N = 106,107) was conducted at Radioactive Isotope Beam Factory at RIKEN by using in-flight fission of a 345-MeV/u 238U primary beam. A previously unreported isomeric state at…
View article: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math>-ray spectroscopy of a four-quasiparticle isomer band in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Re</mml:mi><mml:mprescripts/><mml:none/><mml:mn>174</mml:mn></mml:mmultiscripts></mml:math>
-ray spectroscopy of a four-quasiparticle isomer band in Open
Excited states in 174Re have been populated in fusion-evaporation reactions at the Australian National University, and γ-ray spectroscopy has been used to determine the level structure and to deduce the underlying nucleon configurations. T…