7 results on '"Tessler, M."'
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2. Measuring neutron capture rates on ILL-produced unstable isotopes (147Pm, 171Tm and 204Tl, and plans for 79Se and 163Ho) for nucleosynthesis studies.
- Author
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Köster, U., Lerendegui-Marco, J., Guerrero, C., Domingo-Pardo, C., Casanovas, A., Dressler, R., Halfon, S., Heinitz, S., Kivel, N., Paul, M., Schumann, D., and Tessler, M.
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NEUTRON capture ,STABLE isotopes ,NUCLEOSYNTHESIS ,NUCLEAR reactors ,NUCLEAR cross sections - Abstract
Neutron capture cross sections are among the main inputs for nucleosynthesis network calculations. Although well known for the majority of the stable isotopes, this quantity is still unknown for most of the unstable isotopes of interest. A recent collaboration between ILL, PSI, U. Sevilla and IFIC aims at producing the isotopes of interest at ILL, preparing suitable targets at PSI, and measuring their capture cross sections at facilities such as n_TOF/CERN, LiLiT and the Budapest Research Reactor (BRR). This work is focused on the description of the different beams and techniques and shows some highlights of the preliminary results of the capture measurements on
171 Tm,147 Pm and204 Tl, along with the future plans for79 Se and163 Ho. [ABSTRACT FROM AUTHOR]- Published
- 2018
3. Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics.
- Author
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Guerrero, C., Lerendegui-Marco, J., Domingo-Pardo, C., Casanovas, A., Dressler, R., Halfon, S., Heinitz, S., Kivel, N., Köster, U., Paul, M., Quesada-Molina, J. M., Schumann, D., Tarifeño-Saldivia, A., Tessler, M., Weissman, L., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., and Balibrea, J.
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THULIUM isotopes ,PROMETHIUM isotopes ,NUCLEAR astrophysics ,TIME-of-flight spectrometry ,NEUTRON capture ,NUCLEOSYNTHESIS - Abstract
The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,γ) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of
147 Pm and171 Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on146 Nd and170 Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n TOF facility using the 19 and 185m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6 D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of147 Pm and171 Tm. Activation experiments on the same147 Pm and171 Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
4. Stellar 30-keV neutron capture in 94, 96Zr and the [formula omitted] photonuclear reaction with a high-power liquid-lithium target.
- Author
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Tessler, M., Paul, M., Arenshtam, A., Feinberg, G., Friedman, M., Halfon, S., Kijel, D., Weissman, L., Aviv, O., Berkovits, D., Eisen, Y., Eliyahu, I., Haquin, G., Kreisel, A., Mardor, I., Shimel, G., Shor, A., Silverman, I., and Yungrais, Z.
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NEUTRON capture , *ZIRCONIUM isotopes , *PHOTONUCLEAR reactions , *LITHIUM compounds , *NUCLEAR cross sections , *RADIOACTIVITY - Abstract
A high-power Liquid-Lithium Target (LiLiT) was used for the first time for neutron production via the thick-target Li 7 ( p , n ) Be 7 reaction and quantitative determination of neutron capture cross sections. Bombarded with a 1–2 mA proton beam at 1.92 MeV from the Soreq Applied Research Accelerator Facility (SARAF), the setup yields a 30-keV quasi-Maxwellian neutron spectrum with an intensity of 3– 5 × 10 10 n / s , more than one order of magnitude larger than present near-threshold Li 7 ( p , n ) neutron sources. The setup was used here to determine the 30-keV Maxwellian averaged cross section (MACS) of 94 Zr and 96 Zr as 28.0 ± 0.6 mb and 12.4 ± 0.5 mb respectively, based on activation measurements. The precision of the cross section determinations results both from the high neutron yield and from detailed simulations of the entire experimental setup. We plan to extend our experimental studies to low-abundance and radioactive targets. In addition, we show here that the setup yields intense high-energy (17.6 and 14.6 MeV) prompt capture γ rays from the Li 7 ( p , γ ) Be 8 reaction with yields of ∼ 3 × 10 8 γ s − 1 mA − 1 and ∼ 4 × 10 8 γ s − 1 mA − 1 , respectively, evidenced by the Zr 90 ( γ , n ) Zr 89 photonuclear reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
5. Measurement of 63,65Cu(n, γ)64,66Cu and 59Co(n, γ)60Co Maxwellian-averaged neutron-capture cross sections.
- Author
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Weissman, L., Tessler, M., Barak, A., Dafna, H., Grin, A., Kaizer, B., Kijel, D., Kreisel, A., Paul, M., Perry, A., Silverman, I., Tamim, N., and Zchut, T.
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COBALT isotopes , *COPPER isotopes , *NUCLEOSYNTHESIS , *HEAVY elements , *PROTON beams , *NEUTRON sources , *NEUTRON capture - Abstract
Knowledge of the neutron capture of copper and cobalt isotopes is important for the understanding of abundances of the heavier elements produced via the weak s process. There are considerable discrepancies for the 63Cu (n, γ) 64Cu and 65Cu (n, γ) 66Cu cross-section values in the literature. New measurements of these cross sections were performed at the SARAF phase I facility using a high-power quasi-Maxwellian neutron source produced by irradiation of the liquid-lithium target (LiLiT) with an intense continuous-wave proton beam. The cross sections were measured by counting the activity of the irradiated targets. The measurement allowed us to evaluate the 63Cu (n, γ) 64Cu, 65Cu (n, γ) 66Cu, and 59Co (n, γ) 60Co Maxwellian averaged cross sections at 30 keV, obtaining values of 70.4 ± 1.8exp ± 2.4syst, 26.8 ± 1.5exp ± 1.0syst, and 38.1 ± 0.9exp ± 0.9syst mb, respectively. The results are compared with previous measurements in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. The s-process in the Nd-Pm-Sm region: Neutron activation of 147Pm.
- Author
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Guerrero, C., Tessler, M., Paul, M., Lerendegui-Marco, J., Heinitz, S., Maugeri, E.A., Domingo-Pardo, C., Dressler, R., Halfon, S., Kivel, N., Köster, U., Palchan-Hazan, T., Quesada, J.M., Schumann, D., and Weissman, L.
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METASTABLE states , *HEAVY elements , *NUCLEAR reactions , *NEUTRON capture , *NEODYMIUM isotopes , *NEUTRONS , *PHYSICS - Abstract
The Nd-Pm-Sm branching is of interest for the study of the s -process, related to the production of heavy elements in stars. As 148Sm and 150Sm are s -only isotopes, the understanding of the branching allows constraining the s -process neutron density. In this context the key physics input needed is the cross section of the three unstable nuclides in the region: 147Nd (10.98 d half-life), 147Pm (2.62 yr) and 148Pm (5.37 d). This paper reports on the activation measurement of 147Pm, the longest-lived of the three nuclides. The cross section measurement has been carried out by activation at the SARAF LiLiT facility using a 56(2) μg target. Compared to the single previous measurement of 147Pm, the measurement presented herein benefits from a target 2000 times more massive. The resulting Maxwellian Averaged Cross Section (MACS) to the ground and metastable states in 148Pm are 469(50) mb and 357(27) mb. These values are 41% higher (to the ground state) and 15% lower (to the metastable state) than the values reported so far, leading however to a total cross section of 826(107) mb consistent within uncertainties with the previous result and hence leaving unchanged the previous calculation of the s -process neutron density. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
7. Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics
- Author
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E. Leal-Cidoncha, P. M. Milazzo, M. Mastromarco, Rene Reifarth, O. Aberle, Simone Gilardoni, A. Gawlik, J. M. Quesada-Molina, Thomas Rauscher, D. Radeck, Michael Paul, J. Marganiec, R. Cardella, E. Berthoumieux, Javier Praena, S. Lo Meo, Leonid Weissman, M. Diakaki, M. Kokkoris, A. S. Brown, L. Tassan-Got, Anton Wallner, M. Caamaño, F. Cerutti, M. Tessler, L. Cosentino, J. Balibrea, S. Valenta, G. Cortes, A. Stamatopoulos, Deniz Kurtulgil, A. Oprea, N. V. Sosnin, J. Heyse, Marco Calviani, F. Mingrone, J. Andrzejewski, A. G. Smith, A. Kimura, D. Macina, Ariel Tarifeño-Saldivia, S. J. Lonsdale, J. L. Tain, A. Saxena, A. R. García, F. Gunsing, N. Patronis, Annamaria Mazzone, Petar Žugec, M. Bacak, I. Duran, P. Schillebeeckx, Philip Woods, S. Halfon, A. Casanovas, P. F. Mastinu, Ulli Köster, J. Lerendegui-Marco, P. Ferreira, Hideo Harada, Alfredo Ferrari, Mario Barbagallo, S. Warren, R. Dressler, Cristian Massimi, V. Variale, A. Kalamara, C. Weiss, D. Schumann, R. Vlastou, G. Tagliente, P. Kavrigin, I. F. Gonçalves, M. Sabaté-Gilarte, P. C. Rout, E. Mendoza, Y. H. Chen, Alexandru Negret, E. Griesmayer, R. Nolte, L. A. Damone, S. Heinitz, F. Becvar, A. Tsinganis, C. Lederer, A. Masi, E. Jericha, T. Glodariu, Paolo Finocchiaro, Damir Bosnar, Y. Kadi, F. Käppeler, J. A. Ryan, D. G. Jenkins, E. A. Maugeri, K. Göbel, N. Kivel, Ignacio Porras, Nicola Colonna, E. Dupont, G. Vannini, T. Wright, M. Krtička, E. González, M. A. Cortés-Giraldo, B. Fernández-Domínguez, T. Martinez, F. Calviño, L. Audouin, H. Leeb, Alberto Mengoni, J. Perkowski, Carlo Rubbia, V. Vlachoudis, Carlos Guerrero, P. Vaz, Alberto Ventura, A. Musumarra, E. Chiaveri, D. Cano-Ott, A. Pavlik, C. Domingo-Pardo, J. Billowes, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. NEMEN - Nanoenginyeria de materials aplicats a l'energia, Vannini, G., Mengoni, A., Lo Meo, S., Guerrero, C., Lerendegui-Marco, J., Domingo-Pardo, C., Casanovas, A., Dressler, R., Halfon, S., Heinitz, S., Kivel, N., Köster, U., Paul, M., Quesada-Molina, J.M., Schumann, D., Tarifeño-Saldivia, A., Tessler, M., Weissman, L., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Becvar, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Cerutti, F., Chen, Y.H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Diakaki, M., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Göbel, K., García, A.R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I.F., González, E., Griesmayer, E., Gunsing, F., Harada, H., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kokkoris, M., Krticka, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Leeb, H., Meo, S. Lo, Lonsdale, S.J., Macina, D., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E.A., Mazzone, A., Mendoza, E., Milazzo, P.M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Radeck, D., Rauscher, T., Reifarth, R., Rout, P.C., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Smith, A.G., Sosnin, N.V., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tassan-Got, L., Tsinganis, A., Valenta, S., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P.J., Wright, T., Ugec, P., and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear
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QC1-999 ,Neutron ,Scintillator ,01 natural sciences ,Nuclear physics ,Physics and Astronomy (all) ,Stellar nucleosynthesis ,Nucleosynthesis ,0103 physical sciences ,Neutron cross section ,010306 general physics ,Nuclear Experiment ,Physics ,Energies::Energia nuclear [Àrees temàtiques de la UPC] ,Neutrons ,Isotope ,Física [Àrees temàtiques de la UPC] ,010308 nuclear & particles physics ,Tof ,Time of flight ,Neutron capture ,13. Climate action ,Nucleosíntesi - Abstract
The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,γ ) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of 147Pm and 171Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on 146Nd and 170Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n TOF facility using the 19 and 185m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of 147Pm and 171Tm. Activation experiments on the same 147Pm and 171Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well., The authors acknowledge financial support by Spanish FPA2013-45083-P and FPA2014-53290-C2-2-P projects and the EC FP7 projects NeutAndalus (Grant No. 334315) and CHANDA (Grant No. 605203).
- Published
- 2017
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