| 1. |
- Andreyev, A. N., et al.
(författare)
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alpha-decay of the new isotope Po-187 : Probing prolate structures beyond the neutron mid-shell at N=104
- 2006
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 73:4, s. 044324-
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Tidskriftsartikel (refereegranskat)abstract
- The new neutron-deficient isotope Po-187 has been identified in the complete fusion reaction Ti-46+Sm-144 -> Po-187+3n at the velocity filter SHIP. Striking features of the Po-187 alpha decay are the strongly-hindered decay to the spherical ground state and unhindered decay to a surprisingly low-lying deformed excited state at 286 keV in the daughter nucleus Pb-183. Based on the potential energy surface calculations, the Po-187 ground state and the 286 keV excited state in Pb-183 were interpreted as being of prolate origin. The systematic deviation of the alpha-decay properties in the lightest odd-A Po isotopes relative to the smooth behavior in the even-A neighbors is discussed. Improved data for the decay of Bi-187(m,g) were also obtained.
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| 2. |
- Andreyev, A. N., et al.
(författare)
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alpha decay of the new isotopes Rn-193,Rn-194
- 2006
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:6, s. 064303-
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Tidskriftsartikel (refereegranskat)abstract
- The new neutron-deficient isotopes Rn-193,Rn-194 have been identified in the complete fusion reaction Cr-52+Sm-144 -> Rn-196(*) at the velocity filter SHIP. The alpha-decay energy and half-life value of Rn-194 were determined to be E-alpha=7700(10) keV and T-1/2=0.78(16) ms, respectively. For Rn-193 the half-life of T-1/2=1.15(27) ms and two alpha lines at E-alpha 1=7685(15) keV, I-alpha 1=74(20)% and E-alpha 2=7875(20) keV, I-alpha 2=26(12)% were found. The decay pattern of Rn-193, which is substantially different from that of the heavier odd-A Rn isotopes, provides first experimental evidence for the long-predicted deformation in the very neutron-deficient Rn nuclei.
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| 3. |
- Antalic, S., et al.
(författare)
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The new isotopes in Po-Rn region
- 2007
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1557-1560
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Tidskriftsartikel (refereegranskat)abstract
- This contribution reviews the results of the recent experiments at the velocity filter SHIP in GSI Darmstadt obtained in the region of neutron deficient isotopes from lead to radon. The data for new very neutron-deficient isotopes Po-187, Rn-193,Rn-194 and their decay properties are presented. The isotopes were produced and identified in the complete fusion reactions Ti-46+Sm-144 -> Po-187+3n and Cr-52+Sm-144 -> Rn-194,Rn-193+2,3n.
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| 4. |
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| 5. |
- Streicher, D, et al.
(författare)
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Demonstration of measurements using impulse-radar, ultrasonic echo and impact-echo on a pre-stressed concrete railway bridge in Duisburg / Germany : Sustainable Bridges Background document SB 3.17
- 2007
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Rapport (refereegranskat)abstract
- Non-destructive test- (NDT-) methods are not yet commonly used for inspection of concrete structures. The automated application of enhanced methods as impulse radar, ultra sonic echo and impact-echo during inspection and condition assessment of existing prestressed concrete bridge structures is tested in this deliverable. These methods were used at a railway bridge in Duisburg/Germany to determine thickness of structures and to localize reinforcementand tendon ducts. The automated tests were performed in October 2005.As results, the tendon ducts in the area of the bridge deck and the web were located using impulse-radar and ultrasonic echo. Advantage of echo-measurement set-up is the accessibility only from one side. The accuracy of the determination of the thickness of the structures or the concrete cover of rebar and tendons depends on the calculation of the wave velocities. Structural elements of known thickness or the radar CMP (Common Mid Point) measurements might be used as references for calibration of the wave velocities. Accurate information about the localisation of tendons was not achieved with impact-echo at this bridge. But investigations have shown that geometry-effects can be reduced by measurements in transmission arrangement.
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| 6. |
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