| 1. |
- Ghazi Moradi, Farnaz, 1976-, et al.
(författare)
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Character of particle-hole excitations in Ru-94 deduced from gamma-ray angular correlation and linear polarization measurements
- 2014
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 89:1, s. 014301-
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Tidskriftsartikel (refereegranskat)abstract
- Linear polarization and angular correlations of gamma-rays depopulating excited states in the neutron-deficient nucleus Ru-94(44)50 have been measured, enabling firm spin-parity assignments for several excited states in this nucleus. The deduced multipolarities of strong transitions in the yrast structure were found to be mostly of stretched M1, E1, and E2 types and, in most cases, in agreement with previous tentative assignments. The deduced multipolarity of the 1869 keV and the connecting 257 and 1641 keV transitions indicates that the state at 6358 keV excitation energy has spin parity 12(1)(-) rather than 12(3)(+) as proposed in previous works. The presence of a 12(1)(-) state is interpreted within the framework of large-scale shell-model calculations as a pure proton-hole state dominated by the pi(p(1/2)(-1)circle times g(9/2)(-5)) and pi(p(3/2)(-1) g(9/2)(-5)) configurations. A new positive-parity state is observed at 6103 keV and is tentatively assigned as 12(2)(+). The 14(1)(-) state proposed earlier is reassigned as 13(4)(-) and is interpreted as being dominated by neutron particle-hole core excitations. The strengths of several E1 transitions have been measured and are found to provide a signature of core-excited configurations.
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| 2. |
- Ghazi Moradi, Farnaz, et al.
(författare)
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Spectroscopy of the neutron-deficient N=50 nucleus Rh-95
- 2014
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 89:4, s. 044310-
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Tidskriftsartikel (refereegranskat)abstract
- The neutron-deficient semimagic (neutron number N = 50) Rh-95 nucleus has been produced at high spins using the projectile-target system Ca-40 + Ni-58 at 125 MeV beam energy. The gamma-decays of levels populated by the 3p fusion evaporation reaction channel were studied using gamma-gamma coincidences, and 20 new gamma-ray transitions involving 15 new positive-and negative-parity states were observed. Spin and parity for many of the excited states were firmly deduced for the first time using the combined directional angular correlation and direction-polarization techniques. The observed structures are discussed within the framework of large-scale shell model calculations. E1 transition strengths were deduced and used together with the results of the shell model calculations to study the contribution of different particle-hole configurations, in particular for analyzing contributions from core-excited configurations.
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| 3. |
- Ideguchi, E., et al.
(författare)
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High-spin intruder band in In-107
- 2010
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 81:3, s. 034303-
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the neutron-deficient nucleus In-107 were studied via the Ni-58(Cr-52,3p) reaction. In-beam gamma rays were measured using the JUROGAM detector array. A rotational cascade consisting of ten gamma-ray transitions, which decays to the 19/2(+) level at 2.002 MeV, was observed. The band exhibits the features typical for smooth terminating bands that also appear in rotational bands of heavier nuclei in the A similar to 100 region. The results are compared with total Routhian surface and cranked Nilsson-Strutinsky calculations.
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| 4. |
- Bäck, Torbjörn, et al.
(författare)
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Lifetime measurement of the first excited 2(+) state in (108)Te
- 2011
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 84:4, s. 041306-
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Tidskriftsartikel (refereegranskat)abstract
- The lifetime of the first excited 2(+) state in the neutron deficient nuclide (108)Te has been measured for the first time, using a combined recoil decay tagging and recoil distance Doppler shift technique. The deduced reduced transition probability is B(E2;0(g.s.)(+) -> 2(+)) = 0.39(-0.04)(+0.05)e(2)b(2). Compared to previous experimental data on neutron deficient tellurium isotopes, the new data point constitutes a large step (six neutrons) toward the N = 50 shell closure. In contrast to what has earlier been reported for the light tin isotopes, our result for tellurium does not show any enhanced transition probability with respect to the theoretical predictions and the tellurium systematics including the new data is successfully reproduced by state-of-the-art shell model calculations.
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| 5. |
- Ota, S., et al.
(författare)
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Charge resolution of CR-39 plastic nuclear track detectors for intermediate energy heavy ions
- 2011
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 269:12, s. 1382-1388
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Tidskriftsartikel (refereegranskat)abstract
- The charge resolution (delta Z) for heavy ions (nuclear charge: Z = 60 mu m (30 h etching), saturation occurs and there is no further improvement in delta Z. Analysis of the correlations between projectile Z, energy, detector response, and fluctuation of the response make it possible to develop a model to predict the delta Z for projectiles of given Z and energy. The predicted and measured values of delta Z show good agreement within 10%. We conclude that 4
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| 6. |
- Rudolph, Dirk, et al.
(författare)
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Rotational Bands in the Semi-magic Nucleus 57Ni
- 2010
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 37:7
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Tidskriftsartikel (refereegranskat)abstract
- Two rotational bands have been identified and characterized in the proton-magic N = Z + 1 nucleus Ni-57. These bands complete the systematics of well-and superdeformed rotational bands in the light nickel isotopes starting from doubly magic Ni-56 to Ni-60. High-spin states in Ni-57 have been produced in the fusion-evaporation reaction Si-28(S-32, 2p1n)Ni-57 and studied with the gamma-ray detection array GAMMASPHERE operated in conjunction with detectors for evaporated light charged particles and neutrons. The features of the rotational bands in Ni-57 are compared to those of neighbouring isotopes and interpreted by means of configuration-dependent cranked Nilsson-Strutinsky calculations. The two observed high-spin bands are considered signature partners and assigned to configurations with one 1g(9/2) proton and one 1g(9/2) neutron, resulting in an unambiguous understanding of the energetically favoured signature alpha = -1/2 band but a somewhat less satisfactory description of the signature alpha = +1/2 band.
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