Halflife measurements of the rp-process nuclei 61Ga, 63Ge, and 65As
Abstract
Using the A1200 beam analysis device at the National Superconducting Cyclotron Laboratory, we have measured the halflives of several nuclei along the rp-process path near the proton-drip line. Halflife results for 61Ga, 63Ge, and 65As (0.15±0.03 s, 95−25+23 ms, and 0.19−0.07+0.11 s, respectively) and their implications for the rp-process are presented.
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Cited by (48)
Nuclear Data Sheets for A=64
2021, Nuclear Data SheetsThe evaluated experimental data are presented and evaluated for 13 known nuclides of mass 64 (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se). For each nuclide, the best values combining all available data are recommended for spectroscopic properties. No excited states have been identified in 64Ti, 64As, and 64Se. Only one excited state in 64V as an isomer, and three in 64Cr have been identified. Data for excited states in 64Mn, 64Fe, and 64Co remain limited. 64Ni, 64Cu, and 64Zn are the most studied nuclides through various reactions and decays, followed by 64Ga and 64Ge. In the opinion of the evaluators, there are several incomplete or discrepant aspects of the high-spin portion of the level scheme for 64Zn above ≈5 MeV excitation which need to be resolved in further experiments using large γ-detector arrays. The decay schemes of 64Ti β−, 64As ε and 64Se ε are unknown, while very little information is available for 64V β− and 64Cr β−. The decay schemes of 64Mn β−, 64Fe β−, 64Co β− and 64Ge ε are somewhat better known, but still considered incomplete by evaluators. The decay scheme of 64Ga ε decay is known in detail, however there is the possibility of additional levels populated above 4713 keV, as the Q(ε) value is 7171 keV. The β−, β+ and ε decay modes of 64Cu are well known, as this radionuclide is of great importance in applications, for example, as a dosimeter for neutron flux determination in nuclear reactors, and as a radiopharmaceutical for positron emission tomography (PET). This work supersedes earlier full evaluations of A=64 by 2007Si04, 1996Si12, 1991Si03, 1979Ha35 and 1974Au04.
Nuclear Data Sheets for A = 61
2015, Nuclear Data SheetsThe evaluated spectroscopic data are presented for known nuclides of mass 61 (Sc,Ti,V,Cr,Mn,Fe,Co,Ni, Cu,Zn,Ga,Ge). Excited-state data are nonexistent for 61Sc, 61Ti, 61V, and 61Ge. Significant amounts of new data have been added since the previous NDS evaluation of A=61 nuclides (1999Bh04). 61Sc nuclide is now experimentally known, but without any knowledge of its half-life. The ground state half-lives of 61Ti and 61V are now determined. Excited-state data have become available for 61Cr, 61Mn and 61Ga, while for 61Ge, five excited states were erroneously assigned in the previous evaluation, these have been omitted here. Improved and extensive high-spin excitations are available for 61Fe, 61Cu and 61Zn, including several new superdeformed structures in 61Cu and 61Zn. Thermal neutron capture γ-ray data are available in detail from 2004Ra23. The radioactive decay schemes of 61Sc and 61Ti are not known, while those for 61V, 61Fe and 61Ge are poorly known. This work benefited from the earlier full evaluations of A=61 published by 1999Bh04, 1983Ek01 and 1975Au05 and the one published in an ‘update’ mode by 1992Zh31. The data and conclusions presented in the current work supersede those in all the previous evaluations.
Nuclear Data Sheets for A = 62
2012, Nuclear Data SheetsExperimental nuclear spectroscopic data for known nuclides of mass number 62 (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge) have been evaluated and presented together with adopted properties of levels and γ rays. New high-spin data are available for 62Ga, and 62Zn. Results of in-beam γ-ray studies for 62Cu producing high-spin states are in conflict in terms of gamma-ray placements and branching ratios. In the opinion of the evaluators, a detailed study of high-spin structures in 62Cu is needed to obtain a consistent and confident level scheme. Precise studies of superallowed β decay of 62Ga to 62Zn by several groups have extended the decay scheme. No significant new data, since the 2000 NDS for A = 62 (2000Hu18), have been reported for 62Co, 62Ni and 62Cu. No data are yet available for excited states in 62Ti and 62V, and those for 62Cr and 62Ge are scarce. The level lifetime data are available in very few cases. The radioactive decay schemes of 62Ti and 62Ge are unknown, and those for 62V, 62Cr and 92-ms 62Mn are scantily known. The data presented here supersede those in the earlier NDS publications.
Nuclear Data Sheets for A = 65
2010, Nuclear Data SheetsThe evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reactions studies for all isobars with mass number A=65. Not much is known experimentally about 65V and 65Cr, although they are expected to decay by β-emission. Spin/parity assignments for 65Mn, 65Fe, 65As, and 65Se are not firmly established.
Nuclear Data Sheets for A = 66
2010, Nuclear Data SheetsThe evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reactions studies for all isobars with mass number A = 66. The first level- scheme of 66As, from (HI,xnγ), has been included in this evaluation.
Nuclear Data Sheets for A = 64
2007, Nuclear Data SheetsThe evaluated spectroscopic data are presented for known nuclides of mass 64 (V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ga,Ge,As,Se). Excited-state data are nonexistent for 64V, 64Cr, 64As and 64Se. Except for half-lives, no other radioactive decay data are available for the decay of 64V, 64As and 64Se; and those for the decays of 64Cr, 64Mn, 64Fe, 64Co and 64Ge are not considered as definitive. There are several high-spin studies for 64Zn nuclide, but many inconsistencies are noted in this evaluation and complete details of data in these studies are generally lacking in the published literature. This work supersedes earlier full evaluations of A = 64 by 1996Si12, 1979Ha35, 1974Au04 and 1967Ve09; and a mid-strem evaluation by 1991Si03 published in an 'update' mode.
- 1
On leave from Centre d'Etudes Nucleaires de Bordeaux-Gradignan, Le Haut Vigneau, F-33170 Gradignan, France.