Identification of 100Sn and others proton drip-line nuclei in the reaction 112Sn(63 MeV/nucl.)+natNrmNi
Abstract
Six new neutron-deficient nuclei 103Sb, 104Sb, 98In, 91Pd, 89Rh and 87Ru have been identified among the products of quasi-fragmentation of a 112Sn beam (63 MeV/nucl.), in addition to the previously reported 100Sn and 102Sn. Decays of over forty short-lived () isomeric states including new isomer 66mAs were observed in the same reaction.
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Cited by (27)
Nuclear Data Sheets for A=100
2021, Nuclear Data SheetsEvaluated experimental data are presented for 15 known nuclides of mass 100 (Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn). Recommended values are given for level parameters, γ and β radiations, and other spectroscopic information. No excited states are known in 100Rb and 100Sn. Except for isotopic identification, no information is available for the decay of the 100Kr isotope, and limited information is known about the decay properties of the 100Sn isotope. According to Fig. 2 (A/Q versus counts plot) and as mentioned in the text in 2021Su01, 100Br isotope was not observed, although, discovery of 101Br was claimed in this work. In the case of 100Pd, the agreement in the orderings of the γ-ray cascades and γ-ray inventory between various studies of high-spin structures remains poor at high excitation energies (>9 MeV). For 100Y, the assignments of the two previously known half-lives to the respective states (g.s. and the 145-keV isomer) remain to be established. This work supersedes earlier full evaluations of A=100 by 2008Si01, 1997Si09, 1990Si05 and 1974Ko37.
Nuclear Data Sheets for A=98
2020, Nuclear Data SheetsExperimental spectroscopic data on nuclear structure and decay are evaluated for known nuclides of mass 98 (Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In). Detailed evaluation results of individual reactions and decays are presented together with the Adopted values that are recommended for level properties, γ and β radiations, and other spectroscopic information. 98Mo remains as the most extensively studied nuclide via various reactions and decays. Level schemes of Sr, Y, Zr, Tc, and Pd nuclides in this mass chain are also well established to date; while Kr, Rb, Nb, Ag and Cd are amongst the least-studied ones for excited states, with only limited data available for each. On the neutron-rich side, 98Br has been identified in the 9Be(238U,F) reaction, but no spectroscopic data are yet available, while for 98In on the proton-rich side, only the ground state and an isomer are known with half-lives measured but their spin-parities and the absolute level energy of the isomer yet to be determined. While 98Ru and 98Rh have also been extensively studied, large discrepancies exist between the high-spin sections of the proposed level schemes in different measurements, and these need to be clarified and resolved with further experimental investigations to improve the currently-adopted ones, which have been selected from the measurements with higher statistics, considering no other criteria of preference. This work supersedes all the earlier evaluations of A=98 (2003Si07, 1998Si18, 1992Si21, 1983Mu21, 1974Me34).
Nuclear Data Sheets for A = 87
2015, Nuclear Data SheetsThe evaluated experimental data are presented for 14 known nuclides of mass 87 (Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru). New datasets have been added for 87Ga, 87Se, 87Kr, 87Rb, 87Sr, 87Nb, and 87Tc. The observation of and new lifetime measurements for 87As at the NSCL Coupled Cyclotron Facility and the Oak Ridge Isochronous Cyclotron at the HRIBF–ORNL Facility are included in the adopted levels for this isotope. The new evaluation also includes an isomeric level at unknown energy for 87Tc, changes to the adopted levels for 87Nb based on newly published data including an extension of the high spin levels and new lifetime measurements, and new heavy ion data for 87Kr. New high spin levels for 87Rb were observed, indicating possible neutron core excitations. In addition, the ground state lifetime of 87Rb has been revised and a new lifetime measurement for an excited level in 87Rb indicates a possible proton spin flip. New excitation levels have been observed for the first time in 87Se. New direct and precise measurement of atomic masses of 87Tc, 87Mo, 87Nb, 87Zr, 87Mo and 87Tc have greatly improved the Q value landscape in this mass region. This work supersedes the previous A=87 evaluation published in 2002He09, and Q values for all isotopes were updated to incorporate the mass evaluation in 2012Wa38.
Nuclear data sheets for A = 91
2013, Nuclear Data SheetsExperimental nuclear structure and decay data for all known A=91 nuclides (As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd) have been evaluated. This evaluation, covering data received by 1 September 2013, supersedes the 1998 evaluation by C. M. Baglin published in Nuclear Data Sheets 86, 1 (1999) (15 December 1998 literature cutoff), and subsequent evaluations by C. M. Baglin added to the ENSDF database for Kr, Sr and Zr (29 December 2000 literature cutoff) and by B. Singh for 91Tc (6 November 2000 literature cutoff).
The structure of <sup>100</sup>Sn and neighbouring nuclei
2013, Progress in Particle and Nuclear PhysicsThe nuclear structure in the 100Sn region is reviewed. State-of-the-art experimental techniques involving stable and radioactive beam facilities have enabled access to exotic nuclei in its next neighbourhood. The analysis of experimental data has established the shell structure and its evolution towards , seniority conservation and proton–neutron interaction in the g9/2 orbit, the super-allowed Gamow–Teller decay of 100Sn, masses and half lives along the -path, and super-allowed decay beyond 100Sn. The status of theoretical approaches in shell model and mean-field investigations is described and their predictive power assessed. Structure features of 100Sn and its doubly-magic neighbours 56Ni at , 132Sn and 78Ni at are compared. An outlook is given on future developments of experimental and theoretical methods.
Nuclear Data Sheets for A = 89
2013, Nuclear Data SheetsThe evaluated experimental data are presented for 14 known nuclides of mass 89 (Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh). New data on high–spin excitations are available for 89Kr, 89Rb, 89Sr, 89Tc and 89Ru, including a superdeformed structure in 89Tc. Fluorescence studies in 89Y have revealed a large number of new levels in 7–11 MeV range. New two–neutron transfer data are available for 89Zr. New direct and precise measurement of atomic masses of 89Se, 89Br, 89Kr, 89Rb, 89Mo and 89Tc have greatly improved the Q value landscape in this mass region. This work supersedes previous A=89 evaluation published in 1998Si31, and also the older ones 1989Si20, 1975Ko21, and M.W. Johns et al., Nuclear Data Tables A 8, 373 (1970).
In spite of extensive experimental work on the isobaric nuclei of this mass chain several deficiencies remain. The identification of 89Rh isotope remains unconfirmed. The half–lives of ground states of 89Ge, 89As and 89Rh have not been measured, only the lower limits are estimated from time–of–flight in a reaction and experimental arrangement, where produced and identified. The decay schemes of 89Ge, 89As, 89Se, 89Ru and 89Rh are not known, and those for 89Tc and 89Mo are incomplete. High–lying (neutron unbound) levels in 89Kr, expected to be populated in the decay of 89Br, have not been investigated. The spins and parities for levels in 89Kr are largely unassigned, while for 89Tc and 89Ru, only few low–spin excitations are established. For 89Rb, little information is available for high–spin structures. Detailed gamma–ray data are available for 88Sr(n,γ)89Sr reaction, but most of these γ rays remain unassigned in a level scheme. Excited state data are nonexistent for 89Ge, 89As, 89Se, 89Br and 89Rh. The 89Y and 89Zr are the most extensively studied nuclei in A=89.
- 1
On leave of absence from IFD, Warsaw University, 00681 Warsaw, Poland