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27 results on '"Larsen, André"'

1. Experimentally constrained (p,γ) y 89 and (n,γ) y 89 reaction rates relevant to p -process nucleosynthesis

Author

Larsen, André, Giacoppo, F, Görgen, Andreas, Hagen, T.W., Klintefjord, M., Renstrøm, Therese, Rose, S.J., Sahin, Ercan, Siem, Sunniva, Tornyi, T.G., Tveten, G.M., Guttormsen, Magne, Voinov, A., Wiedeking, M., Schwengner, Ronald, Bleuel, Darren D.L., Goriely, Stéphane, Harissopulos, Sotirios, Bello Garrote, F.L., Byun, Y., Eriksen, T.K., Larsen, André, Giacoppo, F, Görgen, Andreas, Hagen, T.W., Klintefjord, M., Renstrøm, Therese, Rose, S.J., Sahin, Ercan, Siem, Sunniva, Tornyi, T.G., Tveten, G.M., Guttormsen, Magne, Voinov, A., Wiedeking, M., Schwengner, Ronald, Bleuel, Darren D.L., Goriely, Stéphane, Harissopulos, Sotirios, Bello Garrote, F.L., Byun, Y., and Eriksen, T.K.

Abstract

The nuclear level density and the γ-ray strength function have been extracted for Y89 by using the Oslo method on Y89(p,p′γ)Y89 coincidence data. The γ-ray strength function displays a low-energy enhancement consistent with previous observations in this mass region (Mo93-98). Shell-model calculations support the conclusion that the observed enhancement is due to strong, low-energy M1 transitions at high excitation energies. The data were further used as input for calculations of the Sr88(p,γ)Y89 and Y88(n,γ)Y89 cross sections with the talys reaction code. Comparison with cross-section data, where available, as well as with values from the BRUSLIB library, shows a satisfying agreement., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2016

2. Statistical nuclear properties and synthesis of 138La

Author

Kheswa, B.V., Hagen, T.W., Koehler, P., Klintefjord, M., Nyhus, Hilde Therese, Papka, Paul, Renstrøm, Therese, Rose, S.J., Sahin, Esin, Siem, Sunniva, Tornyi, T.G., Wiedeking, M., Giacoppo, F, Goriely, Stéphane, Guttormsen, Magne, Larsen, André, Bello Garrote, F.L., Eriksen, T.K., Görgen, Andreas, Kheswa, B.V., Hagen, T.W., Koehler, P., Klintefjord, M., Nyhus, Hilde Therese, Papka, Paul, Renstrøm, Therese, Rose, S.J., Sahin, Esin, Siem, Sunniva, Tornyi, T.G., Wiedeking, M., Giacoppo, F, Goriely, Stéphane, Guttormsen, Magne, Larsen, André, Bello Garrote, F.L., Eriksen, T.K., and Görgen, Andreas

Abstract

The synthesis of the neutron deficient 138La nucleus has been a puzzle for a long time. It has not been clear whether it is produced through photodisintegration processes or neutrino induced reactions due to unavailability of experimental data for nuclear level densities and γ strength functions of 138,139La nuclei. In the present work these nuclear properties have been measured and are used to investigate the synthesis of 138La. The results support the neutrino interactions as a dominant production process for 138La., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2015

3. First evidence of low energy enhancement in Ge isotopes

Author

Renstrøm, Therese, Bernstein, L.A., Bleuel, Darren D.L., Glodariu, Tudor, Görgen, Andreas, Hagen, T.W., Lui, Yiu-Wing, Negi, D., Ruud, I.E., Sahin, Esin, Schwengner, Ronald, Nyhus, Hilde Therese, Shima, Tatsushi, Takahisa, Keiji, Tesileanu, Ovidiu, Tornyi, T.G., Tveten, G.M., Wiedeking, M., Utsunomiya, Hiroaki, Larsen, André, Siem, Sunniva, Guttormsen, Magne, Filipescu, Dan Mihai, Gheorghe, Ioana, Goriely, Stéphane, Renstrøm, Therese, Bernstein, L.A., Bleuel, Darren D.L., Glodariu, Tudor, Görgen, Andreas, Hagen, T.W., Lui, Yiu-Wing, Negi, D., Ruud, I.E., Sahin, Esin, Schwengner, Ronald, Nyhus, Hilde Therese, Shima, Tatsushi, Takahisa, Keiji, Tesileanu, Ovidiu, Tornyi, T.G., Tveten, G.M., Wiedeking, M., Utsunomiya, Hiroaki, Larsen, André, Siem, Sunniva, Guttormsen, Magne, Filipescu, Dan Mihai, Gheorghe, Ioana, and Goriely, Stéphane

Abstract

The γ-strength functions and level densities of 73,74Ge have been extracted from particle-γ coincidence data using the Oslo method. In addition the γ-strength function of 74Ge above the neutron separation threshold, Sn = 10.196 MeV has been extracted from photoneutron measurements. When combined, these two experiments give a γ-strength function covering the energy range of ∼1-13 MeV for 74Ge. This thorough investigation of 74Ge is a part of an international campaign to study the previously reported low energy enhancement in this mass region in the γ-strength function from ∼3 MeV towards lower γ energies. The obtained data show that both 73,74Ge display an increase in strength at low γ energies., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2015

4. Upbend and M1 scissors mode in neutron-rich nuclei - Consequences for r-process (n,γ) reaction rates

Author

Larsen, André, Giacoppo, F, Guttormsen, Magne, Görgen, Andreas, Harissopulos, Sotirios, Leoni, Silvia, Liddick, Sean S.N., Naqvi, F., Nyhus, Hilde Therese, Rose, S.J., Renstrøm, Therese, Goriely, Stéphane, Schwengner, Ronald, Siem, Sunniva, Spyrou, Artemis, Tveten, G.M., Voinov, A., Wiedeking, M., Bernstein, L.A., Bleuel, Darren D.L., Bracco, Angela, Brown, Alex, Camera, Franco, Eriksen, T.K., Frauendorf, Stefan, Larsen, André, Giacoppo, F, Guttormsen, Magne, Görgen, Andreas, Harissopulos, Sotirios, Leoni, Silvia, Liddick, Sean S.N., Naqvi, F., Nyhus, Hilde Therese, Rose, S.J., Renstrøm, Therese, Goriely, Stéphane, Schwengner, Ronald, Siem, Sunniva, Spyrou, Artemis, Tveten, G.M., Voinov, A., Wiedeking, M., Bernstein, L.A., Bleuel, Darren D.L., Bracco, Angela, Brown, Alex, Camera, Franco, Eriksen, T.K., and Frauendorf, Stefan

Abstract

An enhanced probability for low-energy γ-emission (upbend, Eγ <3 MeV) at high excitation energies has been observed for several light and mediummass nuclei close to the valley of stability. Also the M1 scissors mode seen in deformed nuclei increases the γ-decay probability for low-energy γ-rays (Eγ ≈ 2-3 MeV). These phenomena, if present in neutron-rich nuclei, have the potential to increase radiative neutron-capture rates relevant for the r-process. The experimental and theoretical status of the upbend is discussed, and preliminary calculations of (n,γ) reaction rates for neutronrich, mid-mass nuclei including the scissors mode are shown., SCOPUS: cp.j, info:eu-repo/semantics/published

Published
2015

5. Low-energy enhancement of nuclear γ strength and its impact on astrophysical reaction rates

Author

Larsen, André, Eriksen, T.K., Giacoppo, F, Guttormsen, Magne, Görgen, Andreas, Hagen, T.W., Koehler, Paul P.E., Nyhus, Hilde Therese, Renstrøm, Therese, Rose, Steven S.J., Ruud, I.E., Siem, Sunniva, Tornyi, T., Tveten, G.M., Blasi, Nives, Bracco, Angela, Burger, Arnold, Camera, Franco, Leoni, Silvia, Million, Bénédicte, Goriely, Stéphane, Harissopulos, Sotirios, Schiller, Andreas, Voinov, A., Wiedeking, M., Larsen, André, Eriksen, T.K., Giacoppo, F, Guttormsen, Magne, Görgen, Andreas, Hagen, T.W., Koehler, Paul P.E., Nyhus, Hilde Therese, Renstrøm, Therese, Rose, Steven S.J., Ruud, I.E., Siem, Sunniva, Tornyi, T., Tveten, G.M., Blasi, Nives, Bracco, Angela, Burger, Arnold, Camera, Franco, Leoni, Silvia, Million, Bénédicte, Goriely, Stéphane, Harissopulos, Sotirios, Schiller, Andreas, Voinov, A., and Wiedeking, M.

Abstract

An unexpected enhancement in the low-energy part of the γ-strength function for light and medium-mass nuclei has been discovered at the Oslo Cyclotron Laboratory. This enhancement could lead to an increase in the neutron-capture rates up to two orders of magnitude for very exotic, neutron-rich nuclei. However, it is still an open question whether this structure persists when approaching the neutron drip line. © Owned by the authors, published by EDP Sciences, 2014., SCOPUS: cp.p, info:eu-repo/semantics/published

Published
2014

6. Photoneutron cross sections for Mo isotopes: A step toward a unified understanding of (γ,n) and (n,γ) reactions

Author

Utsunomiya, Hiroaki, Kondo, Takeo, Iwamoto, C., Akimune, Hidetoshi, Yamagata, Tamio, Goriely, Stéphane, Larsen, André, Guttormsen, Magne, Martini, Marco, Toyokawa, Hiroyuki, Harada, Hideo, Kitatani, Fumito, Lui, Yiu-Wing, Koehler, Paul P.E., Hilaire, Stéphane, Péru, S., Koning, Arjan J., Utsunomiya, Hiroaki, Kondo, Takeo, Iwamoto, C., Akimune, Hidetoshi, Yamagata, Tamio, Goriely, Stéphane, Larsen, André, Guttormsen, Magne, Martini, Marco, Toyokawa, Hiroyuki, Harada, Hideo, Kitatani, Fumito, Lui, Yiu-Wing, Koehler, Paul P.E., Hilaire, Stéphane, Péru, S., and Koning, Arjan J.

Abstract

Photoneutron cross sections were measured for 94Mo, 95Mo, 96Mo, 97Mo, 98Mo, and 100Mo near the neutron threshold with quasi-monochromatic laser-Compton scattering γ rays. The photoneutron data were analyzed with the Skyrme Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random phase approximation (QRPA) model and the axially symmetric-deformed Gogny HFB plus QRPA model of E1 γ-ray strength. Combining the γ-ray strength function constrained by the present photoneutron data with either the nuclear resonance fluorescence data or the updated Oslo data to supplement the data below the neutron threshold, a thorough analysis of the reverse (n,γ) cross sections is made whenever measurements are available. The Oslo data and the corresponding uncertainties are updated based on the latest results of the s-wave neutron spacing and the average radiative width determined in particular for 96Mo. Finally, radiative neutron capture cross sections for two radioactive nuclei, 93Mo and 99Mo, are deduced with the γ-ray strength function method. © 2013 American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2013

7. Transitional γ strength in Cd isotopes

Author

Larsen, André, Ruud, I.E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, T.W., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrøm, Therese, Schiller, Andreas, Siem, Sunniva, Tveten, G.M., Voinov, A., Wiedeking, M., Larsen, André, Ruud, I.E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, T.W., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrøm, Therese, Schiller, Andreas, Siem, Sunniva, Tveten, G.M., Voinov, A., and Wiedeking, M.

Abstract

The level densities and γ-ray strength functions of 105 ,106,111,112Cd have been extracted from particle-γ coincidence data using the Oslo method. The level densities are in very good agreement with known levels at low excitation energy. The γ-ray strength functions display no strong enhancement for low γ energies. However, more low-energy strength is apparent for 105,106Cd than for 111,112Cd. For γ energies above ≈4 MeV, there is evidence for some extra strength, similar to what has been previously observed for the Sn isotopes. The origin of this extra strength is unclear; it might be due to E1 and M1 transitions originating from neutron skin oscillations or the spin-flip resonance, respectively. © 2013 American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2013

8. Transitional gamma strength in Cd isotopes

Author

Larsen, André, Ruud, I. E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, W. T., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrom, T., Schiller, Andreas, Siem, Sunniva, Tveten, G. M., Voinov, A., Wiedeking, M., Larsen, André, Ruud, I. E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, W. T., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrom, T., Schiller, Andreas, Siem, Sunniva, Tveten, G. M., Voinov, A., and Wiedeking, M.

Abstract

info:eu-repo/semantics/published

Published
2013

9. Transitional gamma strength in Cd isotopes

Author

Larsen, André, Ruud, I. E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, W. T., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrom, T., Schiller, Andreas, Siem, Sunniva, Tveten, G. M., Voinov, A., Wiedeking, M., Larsen, André, Ruud, I. E., Burger, Arnold, Goriely, Stéphane, Guttormsen, Magne, Görgen, Andreas, Hagen, W. T., Harissopulos, Sotirios, Nyhus, Hilde Therese, Renstrom, T., Schiller, Andreas, Siem, Sunniva, Tveten, G. M., Voinov, A., and Wiedeking, M.

Abstract

info:eu-repo/semantics/published

Published
2013

10. 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

11. Primary gamma-ray spectra in 44Ti of astrophysical interest

Author

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

Abstract

info:eu-repo/semantics/published

Published
2012

12. Primary gamma-ray spectra in 44Ti of astrophysical interest

Author

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

Abstract

info:eu-repo/semantics/published

Published
2012

13. 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

14. Gamma‐ray strength functions and their relation to astrophysics

Author

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

Abstract

info:eu-repo/semantics/published

Published
2011

15. Gamma‐ray strength functions and their relation to astrophysics

Author

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

Abstract

info:eu-repo/semantics/published

Published
2011

16. 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

17. Impact of a low-energy enhancement in the γ-ray strength function on the neutron-capture cross section

Author

Larsen, André, Goriely, Stéphane, Larsen, André, and Goriely, Stéphane

Abstract

A low-energy enhancement of the γ-ray strength function in several light and medium-mass nuclei has been observed recently in He3-induced reactions. The effect of this enhancement on (n,γ) cross sections is investigated for stable and unstable neutron-rich Fe, Mo, and Cd isotopes. Our results indicate that the radiative neutron capture cross sections may increase considerably due to the low-energy enhancement when approaching the neutron drip line. This could have non-negligible consequences on r-process nucleosynthesis calculations. © 2010 The American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2010

18. 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

19. Soft structures of gamma-ray strength functions studied with the Oslo method

Author

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

Abstract

info:eu-repo/semantics/published

Published
2010

22. Soft structures of gamma-ray strength functions studied with the Oslo method

Author

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

Abstract

info:eu-repo/semantics/published

Published
2010

23. 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

24. 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

25. 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

26. 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

27. 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

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