[en] The high spin isomers in few-particle configuration with mass number of about 100 and 80 were studied. Spin-gap isomers are observed in many odd-A nuclei as well as in odd-odd nuclei the shell-model prediction for high-spin isomers was carried out. In Pd-95, it was able to be concluded that the observed high spin isomer was the J = 21/2⁺ state (E4 spin-gap). The partial life time of the two decay modes of this isomer was calculated on the basis of the shell model. The prediction of other isomers was made. The spin-values of the predicted isomers changed from nucleus to nucleus. The reason why the spin-gap appears below the J = 21/2⁺ state in Pd-95 is understood by considering the breakdown of the seniority scheme of the proton wave-function in the resultant p-n system. The p-n interaction is important. (Kato, T.)

[en] A possibility of the isomeric states in proton-rich nuclei and the stability of the states against the particle emission are discussed. The shell-model calculation was made at the energy level of the nuclei with 40 < = N, Z < = 50 assuming the inert ¹⁰⁰Sn core. The calculated spectrum for ⁹⁵Pd suggested the existence of the spin-gap isomer of J=21/2⁺ state. The other predicted high-spin isomers in 1 sub(g sub (1/2)) - shell nuclei are tabulated. The possibility of alpha and proton emission was examined for ⁹⁶Cd, and the lifetime of the alpha emission from the J=16⁺ state was estimated to be more than 10⁴ years. The present method of estimation was applied to the well-known direct proton emission process from sup(53m) Co, and a value of 400 sec was obtained, which was compared with the measured value of 20 sec. From these investigation, it was found that the proton emission from high spin states was hindered very much due to a large orbital angular momentum caused by the protons emitted. The similar situation was obtained for other high spin isomers in this mass region. (Asami, T.)

[en] The nuclear structure in the ¹⁰⁰Sn region will be presented. 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 N = Z = 50, seniority conservation and proton.neutron interaction in the g_9/2 orbit, the super-allowed Gamow.Teller decay of ¹⁰⁰Sn, masses and half-lives along the rp-path, and super-allowed α decay beyond ¹⁰⁰Sn. The status of theoretical approaches in shell model and mean-field investigations will be discussed and their predictive power assessed. Selected structure features of ¹⁰⁰Sn and its doubly-magic neighbours ⁵⁶Ni at N = Z, ¹³²Sn and ⁷⁸Ni at N >> Z are compared. This document is composed of an abstract and the slides of the presentation. (author)

[en] The neutron-deficient 1g/sub 9/2/-shell nuclei are studied in the framework of the shell model with the (1g/sub 9/2/,2p/sub 1/2/)/sup -n/ configuration. Several ''spin-gap'' isomers with a half-life of an order of a second are predicted in ⁹⁵Pd, ⁹⁵Ag, ⁹⁶Cd, and ⁹⁷Cd. Among them, the J = (21/2)⁺ state in ⁹⁵Pd is predicted to be an isomer which corresponds to ⁹⁵Pd/sup m/ recently observed by Nolte and Hick. It is also shown that the high-spin isomers above the proton threshold are rather stable against the proton emission

[en] The projectile-target system ⁴⁰Ca+⁵⁸Ni has been used to produce the neutron deficient N=49 isotones ⁹²Tc, ⁹³Ru, ⁹⁴Rh, and ⁹⁵Pd. The multidetector array NORDBALL including particle selection was used. The yrast level scheme could in three cases be determined up to and above spin values corresponding to the highest angular momenta attainable in the previously used configuration spaces for shell model calculations. The yrast level schemes of the N=49 isotones bear a striking relationship to those of the corresponding N=50 isotones. By interpreting the experimental high spin yrast structure in shell model configurations we hope to facilitate the choice of a restricted configuration space to be used for calculations. Generally, there is an intrinsic simplicity in most of the observed yrast or near-yrast states

No abstract available

[en] Masses of nuclides involved in astrophysical rp and νp processes have to be known precisely in order to model these processes reliably. Mass excesses for 90 ground state and 8 isomeric states of neutron-deficient nuclides have been determined with a precision of better than 10 keV with the JYFLTRAP double Penning trap mass spectrometer at the Ion-Guide Isotope Separator On-Line facility in Jyvaeskylae. Highlights of the measurements related to nuclear astrophysics are given. Some of the measured isomers, such as ⁵³Co^m, ⁹⁰Tc^m, and ⁹⁵Pd^m, and implications for the excitation energy of the 21⁺ isomer in ⁹⁴Ag are briefly discussed.

[en] The masses of very neutron-deficient nuclides close to the astrophysical r p- and ν p-process paths have been determined with the Penning trap facilities JYFLTRAP at JYFL/Jyvaeskylae and SHIPTRAP at GSI/Darmstadt. Isotopes from yttrium (Z=39) to palladium (Z=46) have been produced in heavy-ion fusion-evaporation reactions. In total, 21 nuclides were studied, and almost half of the mass values were experimentally determined for the first time: ⁸⁸Tc, ^90-92Ru, ^92-94Rh, and ^94,95Pd. For the ⁹⁵Pd^m, (21/2⁺) high-spin state, a first direct mass determination was performed. Relative mass uncertainties of typically δm/m=5x10^-8 were obtained. The impact of the new mass values has been studied in ν p-process nucleosynthesis calculations. The resulting reaction flow and the final abundances are compared with those obtained with the data of the Atomic Mass Evaluation 2003

[en] The yrast level schemes of three neutron deficient nuclei with mass A≅95 have been studied with the reaction ⁵⁸Ni+⁴⁰Ca at 135 MeV, using the GASP γ-ray array, the ISIS silicon ball, and the n-ring neutron detector. Excited levels, including a (23/2⁺) spin-gap isomer, are reported for the first time in the heaviest N=Z+1 nucleus experimentally investigated, ⁹⁵Ag. In ⁹⁵Pd, the yrast line above the ground state has been observed and connected to states above the known isomeric level 21/2⁺, showing for the first time that this is indeed a spin-gap isomer. In ⁹⁴Pd, the 95.6-keV isomeric transition was confirmed, and its E2 character was firmly established. The experimental observations are compared with current shell-model calculations

[en] During the years 2005-2010 the double-Penning-trap mass spectrometer JYFLTRAP has been used to measure the masses of 90 ground and 8 isomeric states of neutron-deficient nuclides with a typical precision of better than 10keV. The masses of 14 nuclides - ⁸⁴Zr, ^88,89Tc, ^90-92Ru, ^92-94Rh, ^94,95Pd, ^106,108,110Sb - have been experimentally determined for the first time. This article gives an overview on these measurements and their impact on the modeling of the astrophysical rp -process. (orig.)