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| 2. |
- Szymanski, J. J., et al.
(författare)
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A study of the decay mu –> e gamma by the MEGA experiment
- 1996
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Ingår i: Proceedings, 9th Meeting, DPF'96, Minneapolis, USA, August 11-15, 1996. Vol. 1, 2.. ; , s. 1450-1452
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Konferensbidrag (refereegranskat)
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| 3. |
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| 4. |
- Bower, K. N., et al.
(författare)
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The Great Dun Fell experiment 1995 : An overview
- 1999
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Ingår i: Atmospheric Research. - 0169-8095. ; 50:3-4, s. 151-184
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Tidskriftsartikel (refereegranskat)abstract
- During March and April of 1995 a major international field project was conducted at the UMIST field station site on Great Dun Fell in Cumbria, Northern England. The hill cap cloud which frequently envelopes this site was used as a natural flow through reactor to examine the sensitivity of the cloud microphysics to the aerosol entering the cloud and also to investigate the effects of the cloud in changing the aerosol size distribution, chemical composition and associated optical properties. To investigate these processes, detailed measurements of the cloud water chemistry (including the chemistry of sulphur compounds, organic and inorganic oxidised nitrogen and ammonia), cloud microphysics and properties of the aerosol and trace gas concentrations upwind and downwind of the cap cloud were undertaken. It was found that the cloud droplet number was generally strongly correlated to aerosol number concentration, with up to 2000 activated droplets cm-3 being observed in the most polluted conditions. In such conditions it was inferred that hygroscopic organic compounds were important in the activation process. Often, the size distribution of the aerosol was substantially modified by the cloud processing, largely due to the aqueous phase oxidation of S(IV) to sulphate by hydrogen peroxide, but also through the uptake and fixing of gas phase nitric acid as nitrate, increasing the calculated optical scattering of the aerosol substantially (by up to 24%). New particle formation was also observed in the ultrafine aerosol mode (at about 5 nm) downwind of the cap cloud, particularly in conditions of low total aerosol surface area and in the presence of ammonia and HCl gases. This was seen to occur at night as well as during the day via a mechanism which is not yet understood. The implications of these results for parameterising aerosol growth in Global Climate Models are explored.
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| 5. |
- Clark, R M, et al.
(författare)
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Superdeformation in bismuth
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:1, s. 117-123
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Tidskriftsartikel (refereegranskat)abstract
- High angular momentum states in Bi-195-197 are populated in two reactions: W-183(F-19,xn)Bi-202-x and Ta-181(Ne-20,xn)Bi-201-x at beam energies of 108 and 123 MeV, respectively. Gamma rays were detected using the Gammasphere array. Three weakly populated rotational sequences have been found. They each have properties characteristic of other superdeformed bands in this mass region. On the basis of cross-bombardment information we believe that one band belongs to each of Bi-195, Bi-196, and Bi-197. The properties of the bands in the odd-Bi nuclei are best reproduced if the odd proton occupies the favored signature of the [651]1/2 orbital, while the band in Bi-196 has this same proton configuration coupled to an additional N=7 (j(15/2)) neutron. The relative behavior of the J((2)) moments of inertia can be qualitatively understood in terms of Pauli-blocking effects.
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| 6. |
- Beausang, C W, et al.
(författare)
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Lifetimes of yrast and excited superdeformed states in Gd-150 : effect of particle-hole excitations on the deformation
- 1998
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Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 417:1-2, s. 13-19
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Tidskriftsartikel (refereegranskat)abstract
- The quadrupole moments and deformations have been measured for six superdeformed bands in Gd-150. The results indicate evidence for deformation driving properties of both the high-hi intruder and also low-N natural parity states at the superdeformed Fermi surface. Several new transitions have been identified and placed in the low spin non-yrast portion of one of the SD bands.
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| 7. |
- Baldsiefen, G, et al.
(författare)
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Shears bands in Pb-193
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 54:3, s. 1106-1116
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Tidskriftsartikel (refereegranskat)abstract
- Four bands of enhanced dipole transitions, with weak crossovers, have been observed in Pb-195. Three of these bands are connected to the spherical levels. in addition, the spherical level scheme has been extended. The nuclear spectroscopy was done with the early implementation of GAMMASPHERE and HERA arrays of Get detectors. The nucleus Pb-193 was populated in the Yb-174(Mg-24,5n) reaction at beam energies of 129, 131, and 134 MeV. The experimental results are compared to tilted-axis cranking calculations. The systematical behavior of the dipole bands in the heavier odd-A Pb isotopes, Pb-195,Pb-197,Pb-199,Pb-201, is also discussed.
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| 8. |
- Joss, D T, et al.
(författare)
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Lifetime measurements of a triaxial band in Ce-133
- 1998
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Ingår i: Acta Physica Hungarica A. - 1219-7580 .- 1588-2675. ; 7:1, s. 111-112
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Tidskriftsartikel (refereegranskat)abstract
- The Doppler shift attenuation method has been used to determine the transition quadrupole moment of a triaxial band belonging to the gamma-soft nucleus, Ce-133. Doppler broadened lineshape (DBLS) analysis has revealed the magnitude of the Q(t) value to be similar to 2.4 eb. This contribution provides new information of (i) the transition quadrupole moment of this band (ii) the lifetimes of in-band and sidefeeding transitions and (iii) the relative deformations of coexisting nuclear shapes.
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| 9. |
- Joss, D T, et al.
(författare)
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Lifetime measurements of a triaxial band in Ce-133
- 1998
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 58:6, s. 3219-3222
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of states within a triaxial band belonging to;the gamma-soft nucleus Ce-133 have been determined through a Doppler-broadened line shape analysis. A value, Q(t)approximate to 2.2 eb, has been found for the transition quadrupole moment which is considerably smaller than that of superdeformed structures (Q(t)approximate to 7.4 e b) in this mass region. The results are discussed in terms of deformation self-consistent calculations based on the total Routhian surface formalism. [S0556-2813(98)01912-8].
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| 10. |
- McNabb, D P, et al.
(författare)
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Superdeformation in Po-198
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:2, s. R541-R543
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Tidskriftsartikel (refereegranskat)abstract
- The Yb-174(Si-29,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in Po-198. Resulting gamma rays were observed with Gammasphere. A weakly populated superdeformed band of 10 gamma-ray transitions was found and has been assigned to Po-198. This is the first observation of an SD band in the A approximate to 190 region in a nucleus with Z > 83. The J((2))) of the new band is very similar to those of the yrast SD bands in Hg-194 and Pb-196. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.
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