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19 results on '"Syed, Naeem Ul Hasan"'

1. Indirect (n, Υ)91,92Zr Cross Section Measurements for the s-Process

Author

Guttormsen, Magne, Goriely, Stéphane, Larsen, Ann-Cecilie, Görgen, Andreas, Hagen, T.W., Renstrøm, Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, Tagliente, Giuseppe, Toft, H.K., Utsunomiya, Hiroaki, Voinov, A., and Wikan, K.

Subjects
Généralités
Abstract

Nuclear level densities (NLDs) and Υ-ray strength functions (ΥSFs) of 91,92Zr have been extracted from particle-Υ coincidences using the Oslo method. The extracted ΥSF data, combined with photonuclear cross sections, cover the whole energy range from EΥ = 1.5 MeV up�to the giant dipole resonance at EΥ17MeV. The wide-range ΥSF data display structures at EΥ = 9.5 MeV, compatible with a superposition of the spin-flip M1 resonance and a pygmy E1 resonance. Furthermore, the SF shows a minimum at 2–3 MeV and an increase at lower Υ-ray energies. The experimentally constrained NLDs and SFs are shown to reproduce known and Maxwellian-averaged cross sections for Zr using the TALYS reaction code, thus serving as a benchmark for this indirect method of estimating cross sections for Zr isotopes., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2019

2. Quasicontinuum γ decay of 91,92Zr: Benchmarking indirect (n,γ ) cross section measurements for the s process

Author

Guttormsen, Magne Sveen, Goriely, Stephan, Larsen, Ann-Cecilie, Görgen, Andreas, Hagen, Trine Wiborg, Renstrøm, Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, Tagliente, G., Toft, Heidi Kristine, Utsunomiya, H., Voinov, Alexander, and Wikan, Kristine

Abstract

Nuclear level densities (NLDs) and γ-ray strength functions (γSFs) have been extracted from particle-γ coincidences of the 92Zr(p,p′γ)92Zr and 92Zr(p,dγ)91Zr reactions using the Oslo method. The new 91,92ZrγSF data, combined with photonuclear cross sections, cover the whole energy range from Eγ≈1.5MeV up to the giant dipole resonance at Eγ≈17 MeV. The wide-range γSF data display structures at Eγ≈9.5 MeV, compatible with a superposition of the spin-flip M1 resonance and a pygmy E1 resonance. Furthermore, the γSF shows a minimum at Eγ≈2–3MeV and an increase at lower γ-ray energies. The experimentally constrained NLDs and γSFs are shown to reproduce known (n,γ) and Maxwellian-averaged cross sections for 91,92Zr using the talys reaction code, thus serving as a benchmark for this indirect method of estimating (n,γ) cross sections for Zr isotopes. This research was originally published in Physical Review C - Nuclear Physics. © American Physical Society

Published
2017

3. Effect of Pesticide Residues on Health and Different Enzyme Levels in the Milk of Women from Karachi-Pakistan

Author

null Uzma Mehboob, null Mohammad Ahmed Azmi, null Mohammad Arshad Azmi, and null Syed Naeem ul Hasan Naqvi

Subjects
chemistry.chemical_classification, Toxicology, Enzyme, Pesticide residue, chemistry, Biology
Abstract

The aim of this study was to investigate the presence of pesticide residues in human milk and their effects on the enzyme levels (cholinesterase and lactate dehydrogenase) as well as the health status of the pesticide exposed women. Total 135 milk samples from 45 women were collected from nine different divisions of Karachi, Pakistan. In addition ten milk samples were also collected from normal subjects. The milk samples were taken at day 1, day 15 and day 30 from the same women and from the same divisions. The data indicated that only cypermethrin, deltamethrin, malathion and match were identified. The highest concentration 34.86 µg/10 µl of deltamethrin and the lowest concentration 0.336 µg/10 µl of cypermethrin was found in the milk sample. It may be concluded that exposed women showed significant increased and decreased enzyme levels at different division and also complained about the disturbance in the normal functioning of different organ system and possibly produced various ailments and clinically suffered with skin diseases, backache, disturbance in micturition, difficulty in breathing, asthma and hepatitis.

Published
2012

4. Nuclear structure and statistical decay properties of closed and near closed shell nuclei

Author

Syed, Naeem Ul Hasan

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Nuclear Experiment, kjernefysikk
Abstract

This dissertation presents the measurement of level densities and‭ y-ray strength functions of selected warm nuclei in the vicinity of closed and near closed shells‭. These quantities are important for their application in stellar evolution models in astrophysics and in the design and operation of nuclear reactors. ‬The particle beams are impinged on to the target nuclei at the Oslo Cyclotron Laboratory‭ (‬OCL‭). ‬Neutron pick-up and inelastic scattering reactions are used to excite nuclei to high temperatures‭. Then, the excited states decay down to the ground state by y-‬emissions. The resulting‭ y-rays in coincidence with the outgoing charged particle are detected and stored‭‭. ‬The energy distribution of the first‭ y-‬rays in each cascade contains the information of level density and‭ y-‬ray strength function‭.‬ The experimental results are compared with different theoretical models over the entire energy region. It is found that level densities and y-ray strength functions in closed and near closed shell nuclei displayed bump structures‭. ‬These structures can be explained in terms of shell closure effects and breaking of Cooper pairs. In lead nuclei bump structures of the y-ray strength function are found to be more pronounced for completely closed shell nuclei than their neighboring nuclei‭. ‬The y-ray strength functions of vanadium‭, ‬scandium and titanium nuclei have shown a low-energy‭ y-‬ray enhancement‭, ‬which can not presently be explained by theory.‬ ‬The thermodynamic properties like entropy‭, ‬temperature‭, ‬and specific heat capacity‭ of nuclei are deduced from the extracted level densities. ‬The difference of entropy between even-even and even-odd closed shell nuclei is found to be lower than for mid-shell nuclei‭.

Published
2009

5. Primary γ-ray spectra in 44Ti of astrophysical interest

Author

Larsen, André, Goriely, Stéphane, Burger, Arnold, Guttormsen, Magne, Görgen, Andreas, Harissopulos, Sotirios, Kmiecik, Maria, Konstantinopoulos, Theodore, Lagoyannis, Anastasios, Lonnroth, Tom, Mazurek, Katarzyna, Norrby, Markus, Nyhus, Hilde Therese, Perdikakis, Georgios, Schiller, Andreas, Siem, Sunniva, Spyrou, Artemis, Syed, Naeem Ul Hasan, Toft, H.K., Tveten, G.M., Voinov, A., Larsen, André, Goriely, Stéphane, Burger, Arnold, Guttormsen, Magne, Görgen, Andreas, Harissopulos, Sotirios, Kmiecik, Maria, Konstantinopoulos, Theodore, Lagoyannis, Anastasios, Lonnroth, Tom, Mazurek, Katarzyna, Norrby, Markus, Nyhus, Hilde Therese, Perdikakis, Georgios, Schiller, Andreas, Siem, Sunniva, Spyrou, Artemis, Syed, Naeem Ul Hasan, Toft, H.K., Tveten, G.M., and Voinov, A.

Abstract

Primary γ-ray spectra for a wide excitation-energy range have been extracted for 44Ti from particle-γ coincidence data of the 46Ti(p,tγ)44Ti reaction. These spectra reveal information on the γ-decay pattern of the nucleus and may be used to extract the level density and radiative strength function applying the Oslo method. Models of the level density and radiative strength function are used as input for cross-section calculations of the 40Ca(α,γ)44Ti reaction. Acceptable models should reproduce data on the 40Ca(α,γ)44Ti reaction cross section as well as the measured primary γ-ray spectra. This is only achieved when a coherent normalization of the slope of the level density and radiative strength function is performed. Thus, the overall shape of the experimental primary γ-ray spectra puts a constraint on the input models for the rate calculations. © 2012 American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2012

6. Gamma-ray strength functions and their relation to astrophysics

Author

Larsen, André, Burger, Arnold, Görgen, Andreas, Guttormsen, Magne, Hagen, T.W., Nyhus, Hilde Therese, Rekstad, John J.B., Renstrøm, Therese, Rose, Steven S.J., Ruud, I.E., Siem, Sunniva, Syed, Naeem Ul Hasan, Toft, H.K., Tveten, G.M., Wikan, K., Goriely, Stéphane, Algin, E, Agvaanluvsan, Undraa, Lonnroth, Tom, Mitchell, Gerardine, Schiller, Andreas, Voinov, A., Larsen, André, Burger, Arnold, Görgen, Andreas, Guttormsen, Magne, Hagen, T.W., Nyhus, Hilde Therese, Rekstad, John J.B., Renstrøm, Therese, Rose, Steven S.J., Ruud, I.E., Siem, Sunniva, Syed, Naeem Ul Hasan, Toft, H.K., Tveten, G.M., Wikan, K., Goriely, Stéphane, Algin, E, Agvaanluvsan, Undraa, Lonnroth, Tom, Mitchell, Gerardine, Schiller, Andreas, and Voinov, A.

Abstract

The nuclear γ-ray strength function is one of the indispensable inputs needed for reaction-rate calculations, and is particularly important for the neutron-capture cross section. The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract simultaneously nuclear level density and γ-ray strength function from particle-γ coincidence measurements. Data on the strength functions of Sn nuclei as well as for lighter elements are presented. The Sn isotopes all display a resonance-like structure close to the neutron threshold, that could possibly be due to the neutron-skin oscillation mode. This so-called pygmy dipole resonance greatly influences the neutron-capture rates. In the lighter nuclei, an enhancement of the strength function at low γ energies is observed. The possible impact of this increase on Maxwellian-averaged reaction rates has been investigated. © 2011 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2011

7. Soft structures of γ-ray strength functions studied with the Oslo method

Author

Larsen, André, Burger, Arnold, Guttormsen, Magne, Nyhus, Hilde Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, Toft, H.K., Agvaanluvsan, Undraa, Bernstein, Lee L.A., Chankova, R., Mitchell, Gerardine, Goriely, Stéphane, Lonnroth, Tom, Schiller, Andreas, Voinov, A., Larsen, André, Burger, Arnold, Guttormsen, Magne, Nyhus, Hilde Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, Toft, H.K., Agvaanluvsan, Undraa, Bernstein, Lee L.A., Chankova, R., Mitchell, Gerardine, Goriely, Stéphane, Lonnroth, Tom, Schiller, Andreas, and Voinov, A.

Abstract

We present experimental γ-ray strength functions up to Eγ ∼ Sn measured at the Oslo Cyclotron Laboratory for several Sc, V, Mo, and Sn isotopes. For the lighter nuclei, an unexpected enhancement of the strength function at low γ-ray energies has been revealed. This enhancement could potentially have an impact on neutron-capture cross sections for unstable, neutron-rich nuclei. For the Sn isotopes, we observe increased strength around the neutron separation energy Sn., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2010

8. Spectroscopy of transfermium nuclei using the GABRIELA set up at the focal plane of the VASSILISSA recoil separator

Author

Hauschild, Klaus, Lopez-Martens, A., Briançon, Ch, Désesquelles, Pierre, Garcia-Santamaria, Sonsoles, Korichi, Ahmed, Robin, J., Dorvaux, O., Piot, J., Curien, Dominique, Gall, B. P J, Khalfallah, F., Khouaja, A., Roussea, M., Stuttge, Louise, Rowley, Neil, Yeremin, Alexander, Belozerov, Alexey, Chelnokov, Maxim, Chepigin, Victor, Gorshkov, V.A., Isaev, Andrey, Izosimov, Igor, Kabachenko, A.P., Katrasev, Denis, Kutznetzov, A.N., Malyshev, Oleg, Popeko, Andrei, Sagaidak, Roman, Shutov, Alexander, Sokol, Evgeny, Svirikhin, Alexander, Wiborg-Hagen, T., Guttormsen, Magne, Larsen, André, Nyhus, Hilde Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, Hanappe, Francis, Hauschild, Klaus, Lopez-Martens, A., Briançon, Ch, Désesquelles, Pierre, Garcia-Santamaria, Sonsoles, Korichi, Ahmed, Robin, J., Dorvaux, O., Piot, J., Curien, Dominique, Gall, B. P J, Khalfallah, F., Khouaja, A., Roussea, M., Stuttge, Louise, Rowley, Neil, Yeremin, Alexander, Belozerov, Alexey, Chelnokov, Maxim, Chepigin, Victor, Gorshkov, V.A., Isaev, Andrey, Izosimov, Igor, Kabachenko, A.P., Katrasev, Denis, Kutznetzov, A.N., Malyshev, Oleg, Popeko, Andrei, Sagaidak, Roman, Shutov, Alexander, Sokol, Evgeny, Svirikhin, Alexander, Wiborg-Hagen, T., Guttormsen, Magne, Larsen, André, Nyhus, Hilde Therese, Siem, Sunniva, Syed, Naeem Ul Hasan, and Hanappe, Francis

Abstract

An IN2P3-JINR collaboration has launched a project called GABRIELA at the Flerov Laboratory for Nuclear Reactions (FLNR) within the Joint Institute for Nuclear Research (JINR) in Dubna (Russia). The goal of the project is to perform gamma-ray and internal conversion electron spectroscopy of heavy nuclei produced in fusion-evaporation reactions and transported to the focal plane of the recoil separator VASSILISSA. During five experimental campaigns of GABRIELA, the detection system has gained in sensitivity and new spectroscopic information has been obtained for 249Fm, 251Fm, 253No and 255Lr. © 2010 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2010

9. High-K,t1/2=1.4(1) ms, isomeric state in Lr255

Author

Hauschild, Klaus, Lopez-Martens, A., Yeremin, Alexander, Dorvaux, O., Antalic, S., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Gall, B. P J, Görgen, Andreas, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Larsen, André, Malyshev, Oleg, Minkova, Ani, Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Saro, Štefan, Shutov, Alexander, Siem, Sunniva, Stuttge, Louise, Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, Venhart, M., Hauschild, Klaus, Lopez-Martens, A., Yeremin, Alexander, Dorvaux, O., Antalic, S., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Gall, B. P J, Görgen, Andreas, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Larsen, André, Malyshev, Oleg, Minkova, Ani, Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Saro, Štefan, Shutov, Alexander, Siem, Sunniva, Stuttge, Louise, Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, and Venhart, M.

Abstract

An isomeric state in Lr255 with a half-life of t1/2=1.4(1) ms and Ex>720-keV has been observed for the first time using the GABRIELA setup at the focal plane of the VASSILISSA separator. Based on its K-forbiddeness, the configuration of the state is most probably formed by coupling the valence proton to a two quasiparticle neutron excitation. Possible three quasiparticle configurations are discussed. © 2008 The American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2008

10. Spectroscopy of heavy elements at Dubna

Author

Dorvaux, O., Curien, Dominique, Désesquelles, Pierre, Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Sunde, A.-C., Lopez-Martens, A., Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Hauschild, Klaus, Stuttgé, V.I.L., Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, Yeremin, Alexander, Khouaja, A., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Dorvaux, O., Curien, Dominique, Désesquelles, Pierre, Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Sunde, A.-C., Lopez-Martens, A., Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Hauschild, Klaus, Stuttgé, V.I.L., Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, Yeremin, Alexander, Khouaja, A., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, and Chepigin, Victor

Abstract

In 2004, the GABRIELA (Gamma Alpha Beta Recoil Investigation with the Electromagnetic Analyzer VASSILISSA) collaboration started a twofold scientific program at the FLNR (Dubna) laboratory: (a) the systematic study of the behaviour of single particle states within isotopic and isotonic chains with Z = 100-104 as N varies from 152 to 162 and (b) the study of isotopes for which very little spectroscopic information is known. After discussing the Physics motivations and the experimental setup, some new results concerning the structure of 249Fm and 253No nuclei, and some preliminary results on the decay of 217Pa decay are presented., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2008

11. Isomeric states in 253No

Author

Lopez-Martens, A., Hauschild, Klaus, Yeremin, Alexander, Dorvaux, O., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Désesquelles, Pierre, Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Larsen, André, Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Stuttge, Louise, Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, Lopez-Martens, A., Hauschild, Klaus, Yeremin, Alexander, Dorvaux, O., Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Désesquelles, Pierre, Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Larsen, André, Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Stuttge, Louise, Svirikhin, Alexander, Syed, Naeem Ul Hasan, and Theisen, Ch

Abstract

Isomeric states in 253No have been investigated by conversion electron and γ -ray spectroscopy with the GABRIELA detection system. The 31μs isomer reported more than 30 years ago is found to decay to the ground state of 253No by the emission of a 167keV M2 transition. The spin and parity of this low-lying isomeric state are established to be 5/2 + .The presence of another longer-lived isomeric state is also discussed. © Società Italiana di Fisica and Springer-Verlag 2007., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2007

12. Gamma and electron spectroscopy of heavy nuclei at FLNR JINR

Author

Yeremin, Alexander, Belozerov, Alexey, Chelnokov, Maxim, Chepigin, Victor, Gorshkov, V.A., Kabachenko, A.P., Malyshev, Oleg, Oganessian, Yu.Ts., Popeko, Andrei, Shutov, Alexander, Svirikhin, Alexander, Lopez-Martens, A., Hauschild, Klaus, Briançon, Ch, Korichi, Ahmed, Curien, Dominique, Dorvaux, O., Gall, B. P J, Khalfallah, F., Rousseau, Marc, Rowley, Neil, Guttormsen, Magne, Siem, Sunniva, Sunde, A.-C., Syed, Naeem Ul Hasan, Hanappe, Francis, Minkova, Ani, Sharo, S., Venhart, M., Theisen, Ch, Yeremin, Alexander, Belozerov, Alexey, Chelnokov, Maxim, Chepigin, Victor, Gorshkov, V.A., Kabachenko, A.P., Malyshev, Oleg, Oganessian, Yu.Ts., Popeko, Andrei, Shutov, Alexander, Svirikhin, Alexander, Lopez-Martens, A., Hauschild, Klaus, Briançon, Ch, Korichi, Ahmed, Curien, Dominique, Dorvaux, O., Gall, B. P J, Khalfallah, F., Rousseau, Marc, Rowley, Neil, Guttormsen, Magne, Siem, Sunniva, Sunde, A.-C., Syed, Naeem Ul Hasan, Hanappe, Francis, Minkova, Ani, Sharo, S., Venhart, M., and Theisen, Ch

Abstract

Detailed spectroscopic information of excited nuclear states in deformed transfermium nuclei is scarce. Most of the information available today has been obtained from investigations of fine structure α decay. Although α decay gives access to hindrance factors and lifetimes which are strongly correlated to shell/subshell closures and the presence of isomers, only the combined use of γ and conversion electron spectroscopy allows the precise determination of excitation energy, spin and parity of nuclear levels. In particular, the study of odd isotopes gives crucial information on the single particle states available at and around the Fermi surface. In the following, the preliminary results of decay studies using α - γ and α - beta coincidences at the focal plane of the VASSILISSA recoil separator are presented. © 2007 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2007

13. Detailed spectroscopy of Fm249

Author

Lopez-Martens, A., Hauschild, Klaus, Yeremin, Alexander, Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Dorvaux, O., Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Larsen, André, Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Svirikhin, Alexander, Syed, Naeem Ul Hasan, Theisen, Ch, Lopez-Martens, A., Hauschild, Klaus, Yeremin, Alexander, Belozerov, Alexey, Briançon, Ch, Chelnokov, Maxim, Chepigin, Victor, Curien, Dominique, Dorvaux, O., Gall, B. P J, Gorshkov, V.A., Guttormsen, Magne, Hanappe, Francis, Kabachenko, A.P., Khalfallah, F., Korichi, Ahmed, Larsen, André, Malyshev, Oleg, Minkova, Ani, Oganessian, Yu.Ts., Popeko, Andrei, Rousseau, Marc, Rowley, Neil, Sagaidak, Roman, Sharo, S., Shutov, Alexander, Siem, Sunniva, Svirikhin, Alexander, Syed, Naeem Ul Hasan, and Theisen, Ch

Abstract

Excited states in Fm249 were populated via the α decay of No253 and the subsequent decay was observed with the GABRIELA detection system installed at the focal plane of the VASSILISSA recoil separator. The energies, spins, and parities of these states could be established through combined α,γ, and conversion-electron spectroscopy. The first members of the ground-state rotational band were identified. Their excitation energies as well as the observation of a cross-over E2 transition confirm the assignment of 7/2+[624] for the ground state of Fm249. Two excited states were also observed and their decay properties suggest that they correspond to the particle excitation 9/2-[734] and hole excitation 5/2+[622]. The analysis suggests that the 279-keV transition de-exciting the 9/2- state has anomalous E1 conversion coefficients. © 2006 The American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2006

16. Gamma strength function in closed shell nuclei

Author

Syed, Naeem Ul Hasan, primary, Guttormsen, Magne, additional, Larsen, Anne-Cecilie, additional, Siem, S., additional, Ingebretsen, Finn, additional, Rekstad, J., additional, Schiller, Arwed, additional, and Voinov, Alexander, additional

Published
2008
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18. Extracting Experimental Level Densities in A ∼ 207 – 208 Nuclei.

Author

Syed, Naeem-Ul-Hasan, Guttormsen, M., Siem, S., Ingebretsen, F., Lönnroth, T., Rekstad, J., Schiller, A., Sunde, A. C., Chankova, R., and Ødegård, S. W.

Subjects
*NUCLEAR energy, *NUCLEAR physics, *PHYSICS, *PHYSICAL sciences, *NUCLEAR excitation
Abstract

The energy dependent nuclear level densities of 205–208Pb nuclei below the nuclear binding energies were determined by using the Oslo method. The experimental primary γ-ray per excitation energy bin have been extracted for scattering and transfer reactions. The Axel-Brink hypothesis was then used to separate out level density and γ-strength function from the primary γ spectra. The influence of closed shells is quite obvious in the measured level densities. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2006
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