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| 3. |
- FAHLANDER, C, et al.
(författare)
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IN-BEAM SPECTROSCOPY OF TE-110
- 1994
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 577:3-4, s. 773-785
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Tidskriftsartikel (refereegranskat)abstract
- The neutron-deficient nucleus Te-110 has been investigated by in-beam spectroscopic methods using the NORDBALL multi-detector array. Except for the energy of one level observed in alpha-decay, excited states in Te-110 were previously unknown. The level scheme constructed from gamma gamma-coincidence relationships is presented with tentative spin assignments up to I-pi = 21(-). Above spin 8(+) the yrast states have negative parity. They are most likely the members of a band predominantly based on the nu(h(11/2)g(7/2)) two-quasiparticle configuration. A band crossing is observed at I-pi approximate to 17(-). It is suggested to be caused by the alignment of two h(11/2) neutrons. The cranked shell model correctly predicts the spin alignment, but fails to reproduce the observed band crossing frequency, possibly because of octupole effects.
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| 4. |
- JOHNSON, A, et al.
(författare)
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HIGH-SPIN STUDIES NEAR SN-100 WITH NORDBALL - NEW RESULTS ON IN-102, IN-104 AND SB-108
- 1993
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Konferensbidrag (refereegranskat)abstract
- The NORDBALL detector array has been used in a gamma-ray spectroscopic study of neutron deficient nuclei close to 100Sn. A beam of 270 MeV 58Ni ions was used to bombard a target of Fe-54. Reaction channel separation was achieved with a 4pi charged particle Si-ball together with a 1pi neutron detector wall. Altogether 29 final nuclei were identified and excited states were observed for the first time in 8 of them. The weakest identified channel was 100Cd which represented 4.10(-3) % of the observed total yield. Level schemes Of 102In, 104In and 108Sb constructed from gamma-gamma-particle-coincidence and gamma-gamma-angular correlation analyses are presented. The observed structures are discussed in the framework of the nuclear shell-model. In 108Sb also a deformed, strongly coupled, level sequence is observed. This deformed structure is interpreted as built on a pig9/2(-1)xnuh11/2 configuration in agreement with TRS calculations.
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| 5. |
- JUTTINEN, S, et al.
(författare)
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GAMMA-RAY SPECTROSCOPY OF CD-110
- 1994
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 573:2, s. 306-332
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Tidskriftsartikel (refereegranskat)abstract
- The nucleus Cd-110 has been studied using the C-13 and O-18 induced reactions and the NORDBALL multi-detector array. The yrast band was observed to I(pi) = 28+ and a large number of side bands were identified. The h11/2 neutrons were found to play a dominant role in the observed rotational structures. The weakly populated yrast 3187 keV 8+ state is interpreted as arising from the proton g9/2(-2) configuration. Collective bands, where the band members are connected by DELTAI = 1 transitions and where the DELTAI = 2 transitions are not observed, are also reported. These bands are interpreted to have prolate configurations involving both the h11/2 neutrons and the g9/2 protons. The experimental data are discussed in terms of the total routhian surface and cranked shell model calculations.
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| 6. |
- KARNY, M, et al.
(författare)
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EXCITED-STATES OF I-111 AND THE OBSERVATION OF A 21-NS ISOMER
- 1994
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 350:3, s. 179-180
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Tidskriftsartikel (refereegranskat)abstract
- Proton rich nuclei close to Sn-100 have been investigated an-beam using the NORDBALL detector array. A beam of 270 MeV Ni-58 was used to bombard a Fe-54 target. Reaction channel separation was achieved with a 4 pi charged particle multi-detector set-up together with a 1 pi neutron detector wall placed in the forward direction. Gamma-ray transitions belonging do the I-111 nucleus were identified for the first time. A level scheme constructed from gamma-gamma-perticle-coincidence analysis is proposed. The level structure is discussed within the framework of the shell model and the systematics of the heavier odd iodine nuclei.
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| 7. |
- TORMANEN, S, et al.
(författare)
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COMPETING PROTON AND NEUTRON ALIGNMENTS IN NEUTRON-DEFICIENT XE-NUCLEI
- 1994
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 572:2, s. 417-458
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Tidskriftsartikel (refereegranskat)abstract
- High-spin structures of the neutron-deficient Xe-117, Xe-118, Xe-120 isotopes have been studied by in-beam gamma-ray spectroscopic techniques. The final nuclei have been identified by means of charged-particle detectors. Collective rotational bands based on the neutron d5/2, 97/2 and h11/2 configurations have been identified in Xe-117. In the even Xe-118 and Xe-120 nuclei several new side bands were observed and the previously known bands were extended. The present level schemes include two positive-parity bands constructed to high spin in Xe-118, whereas in Xe-120 three such bands were observed. In order to explain these bands, both proton and neutron (h11/2)2 alignments, as well as the shape degree of freedom, have to be invoked. The possible occurrence of a gammaS-band is addressed and a pronounced structural change for more heavy Xe-isotopes is discussed. All negative-parity side bands are interpreted in terms of proton two-quasiparticle excitations. The experimental data are compared with total routhian surface calculations.
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| 8. |
- DOMBRADI, Z, et al.
(författare)
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IDENTIFICATION AND SPECTROSCOPY OF THE TE-108 NUCLEUS
- 1994
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 350:1, s. 3-4
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Tidskriftsartikel (refereegranskat)abstract
- Excited states of Te-108 were populated in the Fe-54 + Ni-58 (270 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction channel separation. Gamma rays belonging to the neutron deficient nucleus Te-108 were identified for the first time. On the basis of gammagamma-coincidence and angular correlation relations a level scheme was constructed with tentative spin and parity assignments. The structure of the nucleus is discussed in the framework of systematics of heavier Te nuclei.
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| 9. |
- DORING, J, et al.
(författare)
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EVIDENCE FOR NEW ISOMERS AND BAND STRUCTURES IN RB-80
- 1992
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 46:6, s. R2127-R2131
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the doubly odd nucleus Rb-80 have mainly been studied via the Zn-68(F-19,alpha3n) reaction at 72 MeV beam energy utilizing the NORDBALL detector system. The level scheme has been extended up to a (15+) state at 4446 keV excitation energy. In the low-spin region seven new isomers with lifetimes in the nanosecond region have been found. In addition, a 6+ isomer with a half-life of the order of mus has been identified at an excitation energy of 494.4 keV. For the level sequence built on this isomer positive parity is suggested and the states are ascribed to the intruder two-quasiparticle configuration (pig9/2 x nug9/2) and collective excitations.
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| 13. |
- Malmsten, M, et al.
(författare)
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Sphingomyelin from milk – characterization of liquid crystalline, liposome and emulsion properties
- 1994
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Ingår i: Journal of the American Oil Chemists Society. - 0003-021X .- 1558-9331. ; 71, s. 1021-1026
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Tidskriftsartikel (refereegranskat)abstract
- The properties of sphingomyelin obtained from bovine milk were investigated. In particular, the properties of liposomes and emulsions prepared from the sphingomyelin, as well as the liquid crystalline behaviour, were investigated and compared to those of related phosphatidylcholine systems. Like sphingomyelins from other sources, sphingomyelin from milk contains a large fraction of long and saturated acyl groups, which results in a high (35-82°C, depending on the lipid concentration) gel-to-liquid crystal transition temperature (Tc). At high sphingomyelin concentrations, a lamellar phase forms above Tc, while below Tc, a swelling gel phase is obtained. The gel phase swells to about 20 wt% water, whereas above Tc, the swelling continues to about 40 wt% water. The limiting areas per molecule are 51 and 68 Å2 below and above Tc, respectively. Sphingomyelin from milk forms liposomes readily in the presence of cholesterol. The liposomes formed have a diameter of about 100 nm, and are stable even at 0.1 M NaCl or HCl. Materials entrapped in the liposomes are released rather slowly (typically 40 % over 5 h). A comparison shows that the sphingomyelin liposomes behave similarly to those formed by phosphatidylcholine systems. Furthermore, sphingomyelin from milk forms stable o/w emulsions with soy bean oil. The size of the emulsion droplets obtained was about 200 nm. Both the size of the emulsion droplets and its dependence on electrolyte addition correlate closely with those of emulsions formed by the corresponding phosphatidylcholine system. Therefore, it is possible to use sphingomyelin as an alternative for saturated phosphatidylcholines, which may be advantageous for oral and dermal pharmaceutical applications, as well as in cosmetics.
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| 14. |
- SEWERYNIAK, D, et al.
(författare)
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IN-BEAM GAMMA-RAY SPECTROSCOPY OF IN-102
- 1993
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 345:2, s. 243-244
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Tidskriftsartikel (refereegranskat)abstract
- Neutron deficient nuclei close to 100Sn have been investigated in-beam by gamma-ray spectroscopic methods using the NORDBALL detector array. A beam of 270 MeV Ni-58 was used to bombard a target of Fe-54. Reaction channel separation was achieved with a 4pi charged particle multi-detector set-up together with a 1pi neutron detector wall placed in the forward direction. Excited states of 102In were identified for the first time. The level scheme constructed from gamma-gamma-particle-coincidence and gamma-gamma-angular correlation analysis is presented. The structure of 102In is discussed and compared to neighboring nuclei in the framework of the nuclear shell-model.
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| 15. |
- SEWERYNIAK, D, et al.
(författare)
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IN-BEAM SPECTROSCOPY AT THE PROTON-DRIP LINE - FIRST OBSERVATION OF EXCITED-STATES IN SB-106 AND SB-107
- 1994
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Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 321:4, s. 323-328
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Tidskriftsartikel (refereegranskat)abstract
- Neutron deficient nuclei close to Sn-100 have been investigated in-beam using the NORDBALL detector array. A target of Fe-54 was bombarded with a beam of Ni-58 at 270 MeV. Evaporation residues were identified by detecting protons and alpha particles in a 4 pi charged particle multi-detector set-up and neutrons in a 1 pi neutron detector wall in coincidence with gamma rays. Excited states of the proton drip line nucleus Sb-106 and of Sb-107 were identified for the first time. The yrast level schemes constructed from gamma-gamma-particle coincidence and gamma-gamma angular correlation analysis are presented and discussed within the framework of the nuclear shell model.
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