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130 results on '"Köster, U."'

1. Radiative Decay of the $^{229m}$Th Nuclear Clock Isomer in Different Host Materials

Author

Pineda, S. V., Chhetri, P., Bara, S., Elskens, Y., Casci, S., Alexandrova, A. N., Au, M., Athanasakis-Kaklamanakis, M., Bartokos, M., Beeks, K., Bernerd, C., Claessens, A., Chrysalidis, K., Cocolios, T. E., Correia, J. G., De Witte, H., Elwell, R., Ferrer, R., Heinke, R., Hudson, E. R., Ivandikov, F., Kudryavtsev, Yu., Köster, U., Kraemer, S., Laatiaoui, M., Lica, R., Merckling, C., Morawetz, I., Morgan, H. W. T., Moritz, D., Pereira, L. M. C., Raeder, S., Rothe, S., Schaden, F., Scharl, K., Schumm, T., Stegemann, S., Terhune, J., Thirolf, P. G., Tunhuma, S. M., Bergh, P. Van Den, Van Duppen, P., Vantomme, A., Wahl, U., and Yue, Z.

Subjects
Nuclear Experiment
Abstract

A comparative vacuum ultraviolet spectroscopy study conducted at ISOLDE-CERN of the radiative decay of the $^{229m}$Th nuclear clock isomer embedded in different host materials is reported. The ratio of the number of radiative decay photons and the number of $^{229m}$Th embedded are determined for single crystalline CaF$_2$, MgF$_2$, LiSrAlF$_6$, AlN, and amorphous SiO$_2$. For the latter two materials, no radiative decay signal was observed and an upper limit of the ratio is reported. The radiative decay wavelength was determined in LiSrAlF$_6$ and CaF$_2$, reducing its uncertainty by a factor of 2.5 relative to our previous measurement. This value is in agreement with the recently reported improved values from laser excitation.

Published
2024

3. Further evidence for shape coexistence in $^{79}$Zn$^{m}$ near doubly-magic $^{78}$Ni

Author

Nies, L., Canete, L., Dao, D. D., Giraud, S., Kankainen, A., Lunney, D., Nowacki, F., Bastin, B., Stryjczyk, M., Ascher, P., Blaum, K., Cakirli, R. B., Eronen, T., Fischer, P., Flayol, M., Alcindor, V. Girard, Herlert, A., Jokinen, A., Khanam, A., Köster, U., Lange, D., Moore, I. D., Müller, M., Mougeot, M., Nesterenko, D. A., Penttilä, H., Petrone, C., Pohjalainen, I., de Roubin, A., Rubchenya, V., Schweiger, Ch., Schweikhard, L., Vilen, M., and Äystö, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Isomers close to doubly-magic $^{78}_{28}$Ni$_{50}$ provide essential information on the shell evolution and shape coexistence near the ${Z=28}$ and ${N=50}$ double shell closure. We report the excitation energy measurement of the $1/2^{+}$ isomer in $^{79}_{30}$Zn$_{49}$ through independent high-precision mass measurements with the JYFLTRAP double Penning trap and with the ISOLTRAP Multi-Reflection Time-of-Flight Mass Spectrometer. We unambiguously place the $1/2^{+}$ isomer at 942(10) keV, slightly below the $5/2^+$ state at 983(3) keV. With the use of state-of-the-art shell-model diagonalizations, complemented with Discrete Non Orthogonal shell-model calculations which are used here the first time to interpret shape coexistence, we find low-lying deformed intruder states, similar to other ${N=49}$ isotones. The $1/2^{+}$ isomer is interpreted as the band-head of a low-lying deformed structure akin to a predicted low-lying deformed band in $^{80}$Zn, and points to shape coexistence in $^{79,80}$Zn similar to the one observed in $^{78}$Ni. The results make a strong case for confirming the claim of shape coexistence in this key region of the nuclear chart., Comment: 10 pages, three figures, two tables. Accepted to Phys. Rev. Lett

Published
2023
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4. Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons

Author

Au, M., Athanasakis-Kaklamanakis, M., Nies, L., Heinke, R., Chrysalidis, K., Köster, U., Kunz, P., Marsh, B., Mougeot, M., Schweikhard, L., Stegemann, S., Gracia, Y. Vila, Düllmann, Ch. E., and Rothe, S.

Subjects
Nuclear Experiment
Abstract

Accelerator-based techniques are one of the leading ways to produce radioactive nuclei. In this work, the Isotope Separation On-Line method was employed at the CERN-ISOLDE facility to produce neptunium and plutonium from a uranium carbide target material using 1.4-GeV protons. Neptunium and plutonium were laser-ionized and extracted as 30-keV ion beams. A Multi-Reflection Time-of-Flight mass spectrometer was used for ion identification by means of time-of-flight measurements as well as for isobaric separation. Isotope shifts were investigated for the 395.6-nm ground state transition in $^{236,237,239}$Np and the 413.4-nm ground state transition in $^{236,239,240}$Pu. Rates of $^{235-241}$Np and $^{234-241}$Pu ions were measured and compared with predictions of in-target production mechanisms simulated with GEANT4 and FLUKA to elucidate the processes by which these nuclei, which contain more protons than the target nucleus, are formed. $^{241}$Pu is the heaviest nuclide produced and identified at a proton-accelerator-driven facility to date. We report the availability of neptunium and plutonium as two additional elements at CERN-ISOLDE and discuss the limit of accelerator-based isotope production at high-energy proton accelerator facilities for nuclides in the actinide region., Comment: 12 pages, 12 figures

Published
2023
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5. In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE

Author

Au, M., Athanasakis-Kaklamanakis, M., Nies, L., Ballof, J., Berger, R., Chrysalidis, K., Fischer, P., Heinke, R., Johnson, J., Köster, U., Leimbach, D., Marsh, B., Mougeot, M., Reilly, J., Reis, E., Schlaich, M., Schweiger, Ch., Schweikhard, L., Stegemann, S., Wessolek, J., Wienholtz, F., Wilkins, S. G., Wojtaczka, W., Düllmann, Ch. E., and Rothe, S.

Subjects
Physics - Instrumentation and Detectors
Abstract

The use of radioactive molecules for fundamental physics research is a developing interdisciplinary field limited dominantly by their scarce availability. In this work, radioactive molecular ion beams containing actinide nuclei extracted from uranium carbide targets are produced via the Isotope Separation On-Line technique at the CERN-ISOLDE facility. Two methods of molecular beam production are studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap. Ion currents of U$^+$, UO$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1-4}^+$, UF$_{1,2}$O$_{1,2}^+$ are reported. Metastable tantalum and uranium fluoride molecular ions are identified. Formation of UO$_{1-3}^+$, U(OH)$_{1-3}^+$, UC$_{1-3}^+$, UF$_{1,2}$O$_{1,2}^+$ from mass-separated beams of U$^+$, UF$_{1,2}^+$ with residual gas is observed in the ion trap. The effect of trapping time on molecular formation is presented., Comment: 6 pages, 7 figures

Published
2023
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6. New detection systems for an enhanced sensitivity in key stellar (n,$\gamma$) measurements

Author

Lerendegui-Marco, J., Babiano-Suárez, V., Balibrea-Correa, J., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., Guerrero, C., Calviño, F., Casanovas, A., Köster, U., Chiera, N. M., Dressler, R., Maugeri, E. A., Schumann, D., and Collaboration, the n_TOF

Subjects
Nuclear Experiment, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. However, neutron capture measurements via the time-of-flight (TOF) technique on key $s$-process nuclei are often challenging. Difficulties arise from the limited mass ($\sim$mg) available and the high sample-related background in the case of the unstable $s$-process branching points. Measurements on neutron magic nuclei, that act as $s$-process bottlenecks, are affected by low (n,$\gamma$) cross sections and a dominant neutron scattering background. Overcoming these experimental challenges requires the combination of facilities with high instantaneous flux, such as n\_TOF-EAR2, with detection systems with an enhanced detection sensitivity and high counting rate capabilities. This contribution reviews some of the latest detector developments in detection systems for (n,$\gamma$) measurements at n\_TOF, such as i-TED, an innovative detection system which exploits the Compton imaging technique to reduce the dominant neutron scattering background and s-TED, a highly segmented total energy detector intended for high flux facilities. The discussion will be illustrated with results of the first measurement of key the $s$-process branching-point reaction $^{79}$Se(n,$\gamma$)., Comment: 7 pages, 4 figures (8 panels). Accepted for publication in EPJ-WOC (proceedings of the NPA-X conference). arXiv admin note: text overlap with arXiv:2301.11199

Published
2023
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7. First measurement of the $^{94}$Nb($n$,$\gamma$) cross section at the CERN n\_TOF facility

Author

Balibrea-Correa, J., Babiano-Suarez, V., Lerendegui-Marco, J., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., Plaza, J., Sánchez-Caballero, A., Calviño, F., Casanovas, A., Guerrero, C., Heinitz, S., Köster, U., Maugeri, E. A., Dressler, R., Schumann, D., Mönch, I., Cristallo, S., Lederer-Woods, C., Aberle, O., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamaño, M., Calviani, M., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramięga, A., Gervino, G., Gilardoni, S., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kaur, G., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lerner, G., Manna, A., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., de Rada, A. Pérez, Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Schillebeeckx, P., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M. E., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., Žugec, P., and Collaboration, the n_TOF

Subjects
Nuclear Experiment
Abstract

One of the crucial ingredients for the improvement of stellar models is the accurate knowledge of neutron capture cross-sections for the different isotopes involved in the $s$-,$r$- and $i$- processes. These measurements can shed light on existing discrepancies between observed and predicted isotopic abundances and help to constrain the physical conditions where these reactions take place along different stages of stellar evolution.In the particular case of the radioactive $^{94}$Nb, the $^{94}$Nb($n$,$\gamma$) cross-section could play a role in the determination of the $s$-process production of $^{94}$Mo in AGB stars, which presently cannot be reproduced by state-of-the-art stellar models. There are no previous $^{94}$Nb($n$,$\gamma$) experimental data for the resolved and unresolved resonance regions mainly due to the difficulties in producing high-quality samples and also due to limitations in conventional detection systems commonly used in time-of-flight experiments.Motivated by this situation, a first measurement of the $^{94}$Nb($n$,$\gamma$) reaction was carried out at CERN n\_TOF, thereby exploiting the high luminosity of the EAR2 area in combination with a new detection system of small-volume C6D6-detectors and a high quality $^{94}$Nb-sample. The latter was based on hyper-pure $^{93}$Nb material activated at the high-flux reactor of ILL-Grenoble. An innovative ring-configuration detection system in close geometry around the capture sample allowed us to significantly enhance the signal-to-background ratio. This set-up was supplemented with two conventional C$_{6}$D$_{6}$ detectors and a high-resolution LaCl$_{3}$(Ce)-detector, which will be employed for addressing reliably systematic effects and uncertainties.At the current status of the data analysis, 18 resonance in $^{94}$Nb+$n$ have been observed for the first time in the neutron energy range from thermal up to 10 keV., Comment: NPA-X conference proceeding

Published
2023
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8. Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

Author

Domingo-Pardo, C., Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Ladarescu, I., Lerendegui-Marco, J., Tain, J. L., Tarifeño-Saldivia, A., Aberle, O., Alcayne, V., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Chiera, N. M., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramiega, A., Gervino, G., Gilardoni, S., González-Romero, E., Guerrero, C., Gunsing, F., Gustavino0, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Käppeler, F., Kaur, G., Kimura, A., Knapová, I., Koester, U., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lederer-Woods, C., Lerner, G., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mönch, I., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., de Rada, A. Pérez, Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Plaza, J., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sánchez, A., Sabaté-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Turko, J., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

This article presents a few selected developments and future ideas related to the measurement of $(n,\gamma)$ data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with $\gamma$-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate $i$ neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area., Comment: preprint submitted to the European Physical Journal A, 11 pages, 4 figures

Published
2022
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11. Status of the HOLMES Experiment

Author

De Gerone, M., Alpert, B., Balata, M., Becker, D. T., Bennett, D. A., Bevilacqua, A., Borghesi, M., Ceruti, G., De Galembert, G. De Bodin, Dressler, R., Faverzani, M., Fedkevych, M., Ferri, E., Fowler, J. W., Gallucci, G., Gard, J. D., Gatti, F., Giachero, A., Hilton, G. C., Köster, U., Lusignoli, M., Manfrinetti, P., Mates, J. A. B., Maugeri, E., Nisi, S., Nucciotti, A., Parodi, L., Pessina, G., Ragazzi, S., Reintsema, C. D., Schmidt, D. R., Schumann, D., Siccardi, F., Swetz, D. S., Ullom, J. N., and Vale, L. R.

Published
2022
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14. KATRIN background due to surface radioimpurities

Author

Fränkle, F.M., Schaller, A., Blaum, K., Bornschein, L., Drexlin, G., Glück, F., Hannen, V., Harms, F., Hinz, D., Johnston, K., Karthein, J., Köster, U., Lokhov, A., Mertens, S., Müller, F., Osipowicz, A., Ranitzsch, P.C.-O., Schlösser, K., Thümmler, T., Trost, N., Weinheimer, C., and Wolf, J.

Published
2022
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15. Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

Author

Domingo-Pardo, C., Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Ladarescu, I., Lerendegui-Marco, J., Tain, J. L., Tarifeño-Saldivia, A., Aberle, O., Alcayne, V., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Chiera, N. M., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., A. Cortés-Giraldo, M., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., García-Infantes, F., Gawlik-Ramięga , A., Gervino, G., Gilardoni, S., González-Romero, E., Guerrero, C., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Käppeler, F., Kaur, G., Kimura, A., Knapová, I., Köster, U., Kokkoris, M., Krtička, M., Kyritsis, N., Lederer-Woods, C., Lerner, G., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mönch, I., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., Pérez de Rada, A., Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Plaza, J., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sánchez, A., Sabaté-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Turko, J., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., and Žugec, P.

Published
2023
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17. Production of 129mXe and 131mXe via neutron activation of 128Xe and 130Xe at ILL-RHF and NCBJ-MARIA high-flux reactors

Author

Chojnacki, M., primary, Kulesz, K., additional, Michelon, I., additional, Azaryan, N., additional, Barbero, E., additional, Crepieux, B., additional, Lica, R., additional, Murawski, Ł., additional, Ziemba, M., additional, Piersa-Siłkowska, M., additional, Vitulova, K., additional, Korgul, A., additional, Jolivet, R.B., additional, Prokopowicz, R., additional, Köster, U., additional, and Kowalska, M., additional

Published
2024
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19. Lifetime measurement for the 15/21− and 13/ 21− levels in Sn129

Author

Kumar, D., primary, Pal, A., additional, Basak, S., additional, Bhattacharjee, T., additional, Alam, S. S., additional, Gerhard, L., additional, Knafla, L., additional, Esmaylzadeh, A., additional, Ley, M., additional, Dunkel, F., additional, Schomaker, K., additional, Régis, J.-M., additional, Jolie, J., additional, Kim, Y. H., additional, and Köster, U., additional

Published
2024
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21. Towards a re-determination of the 42Ar half-life.

Author

Schumann, D., Maugeri, E., Dai, Y., Dressler, R., and Köster, U.

Subjects
OUTGASSING, SPECTROMETRY, QUARTZ
Abstract

We report on a new measurement of the half-life of 42Ar by following its decay over a time period of more than 13 years using γ-ray spectrometry. The obtained value of (39.5 ± 3.6) y confirms the only other, previously measured value of (33 ± 2) y. However, since partial outgassing of the accumulated Ar from the sample cannot be excluded, this value should be understood as a lower limit. The sample has now been stored in a gas-tight quartz ampoule to enable further measurements excluding the outgas effect in order to confirm our finding. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Investigating the prolate-to-oblate shape phase transition: Lifetime measurements and γ spectroscopy of the low-lying negative parity structure in Os193

Author

Knafla, L., primary, Nomura, K., additional, Esmaylzadeh, A., additional, Harter, A., additional, Jolie, J., additional, Karayonchev, V., additional, Kim, Y. H., additional, Köster, U., additional, Ley, M., additional, Michelagnoli, C., additional, Pfeil, A., additional, Régis, J.-M., additional, and von Spee, F., additional

Published
2024
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23. Magnetic moments of thallium isotopes in the vicinity of magic N = 126

Author

Yue, Z., primary, Andreyev, A.N., additional, Barzakh, A.E., additional, Borzov, I.N., additional, Cubiss, J.G., additional, Algora, A., additional, Au, M., additional, Balogh, M., additional, Bara, S., additional, Bark, R.A., additional, Bernerd, C., additional, Borge, M.J.G., additional, Brugnara, D., additional, Chrysalidis, K., additional, Cocolios, T.E., additional, De Witte, H., additional, Favier, Z., additional, Fraile, L.M., additional, Fynbo, H.O.U., additional, Gottardo, A., additional, Grzywacz, R., additional, Heinke, R., additional, Illana, A., additional, Jones, P.M., additional, Judson, D.S., additional, Korgul, A., additional, Köster, U., additional, Labiche, M., additional, Le, L., additional, Lica, R., additional, Madurga, M., additional, Marginean, N., additional, Marsh, B., additional, Mihai, C., additional, Nácher, E., additional, Neacsu, C., additional, Nita, C., additional, Olaizola, B., additional, Orce, J.N., additional, Page, C.A.A., additional, Page, R.D., additional, Pakarinen, J., additional, Papadakis, P., additional, Penyazkov, G., additional, Perea, A., additional, Piersa-Siłkowska, M., additional, Podolyák, Zs., additional, Prosnyak, S.D., additional, Reis, E., additional, Rothe, S., additional, Sedlak, M., additional, Skripnikov, L.V., additional, Sotty, C., additional, Stegemann, S., additional, Tengblad, O., additional, Tolokonnikov, S.V., additional, Udías, J.M., additional, Van Duppen, P., additional, Warr, N., additional, and Wojtaczka, W., additional

Published
2024
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24. Fast-timing Investigation of \(A=128\) Isobars Populated in the \(\beta \)-decay of \(^{128}\)Cd

Author

Llanos-Expósito, M., primary, Fraile, L.M., additional, Benito, J., additional, Acosta, J., additional, Algora, A., additional, Andel, B., additional, Andreyev, A.N., additional, Antalic, S., additional, Bark, R.A., additional, Bernerd, C., additional, Bernier, N., additional, Bhengu, B., additional, Bittner, D., additional, Borge, M.J.G., additional, Briz, J.A., additional, Chrysalidis, K., additional, Cocolios, T.E., additional, Costache, C., additional, Cubiss, J.G., additional, De Witte, H., additional, Encina, N., additional, Esmaylzadeh, A., additional, Favier, Z., additional, Fernández, D., additional, Ferrera, C., additional, Fynbo, H.O.U., additional, García-Távora, V., additional, Georgiev, G., additional, Górska, M., additional, Heinke, R., additional, Herraiz, J.L., additional, Illana, A., additional, Jones, P., additional, Judson, D.S., additional, Jungclaus, A., additional, Karny, M., additional, Korgul, A., additional, Köster, U., additional, Kröll, Th., additional, Labiche, M., additional, Lalkovski, S., additional, Lesch, B., additional, Ley, M., additional, Lică, R., additional, Madurga, M., additional, Mărginean, N., additional, Marsh, B.A., additional, Miernik, K., additional, Mihai, C., additional, Mikolajczuk, M., additional, Mišt, J., additional, Murias, J.R., additional, Nácher, E., additional, Neacsu, C., additional, Nouvilas, V.M., additional, Ntshangase, S., additional, Olaizola, B., additional, Orce, J.N., additional, Page, C., additional, Pakarinen, J., additional, Papadakis, P., additional, Perea, A., additional, Piersa-Siłkowska, M., additional, Podolyak, Zs., additional, Rog, J., additional, Rothe, S., additional, Rozwoda, B., additional, Sánchez-Tembleque, V., additional, Solak, K., additional, Stegemann, S., additional, Stepaniuk, M., additional, Stoica, A., additional, Stryjczyk, M., additional, Tengblad, O., additional, Turturica, A., additional, Turturica, G., additional, Udías, J.M., additional, Ujeniuc, S., additional, Van Duppen, P., additional, von Tresckow, M., additional, Vasilev, I., additional, Warr, N., additional, Yue, Z., additional, and Zajda, S., additional

Published
2024
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25. Low-spin Structures of the \(^{205}\)Pb and \(^{207}\)Pb Nuclei Studied by \(\gamma \)-ray Spectroscopy in Thermal Neutron Capture Reactions

Author

Cieplicka-Oryńczak, N., primary, Michelagnoli, C., additional, Fornal, B., additional, Leoni, S., additional, Benzoni, G., additional, Bottoni, S., additional, Colombi, G., additional, Crespi, F.C.L., additional, Dudouet, J., additional, Iskra, Ł.W., additional, Jentschel, M., additional, Kim, Y.-H., additional, Köster, U., additional, Mărginean, N., additional, Mărginean, R., additional, Mihai, C., additional, Mutti, P., additional, Pacyna, J., additional, Pietralla, N., additional, Ruiz-Martinez, E., additional, Sferrazza, M., additional, and Sieber, J., additional

Published
2024
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26. Lifetime measurements in Rb96 via fast-timing techniques: Investigating shape coexistence at A≃100

Author

Gamba, E. R., primary, Bottoni, S., additional, Iskra, Ł. W., additional, Zavaglia, C., additional, Leoni, S., additional, Fornal, B., additional, Cieplicka-Oryńczak, N., additional, Benzoni, G., additional, Colombi, G., additional, Crespi, F. C. L., additional, Esmaylzadeh, A., additional, Jentschel, M., additional, Jolie, J., additional, Karayonchev, V., additional, Kim, Y. H., additional, Knafla, L., additional, Köster, U., additional, Ley, M., additional, Mǎrginean, N., additional, Mǎrginean, R., additional, Michelagnoli, C., additional, Polettini, M., additional, Porzio, C., additional, Régis, J-.M., additional, Reygadas, D., additional, and Turturica, A., additional

Published
2023
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27. Further Evidence for Shape Coexistence in Zn79m near Doubly Magic Ni78

Author

Nies, L., primary, Canete, L., additional, Dao, D. D., additional, Giraud, S., additional, Kankainen, A., additional, Lunney, D., additional, Nowacki, F., additional, Bastin, B., additional, Stryjczyk, M., additional, Ascher, P., additional, Blaum, K., additional, Cakirli, R. B., additional, Eronen, T., additional, Fischer, P., additional, Flayol, M., additional, Girard Alcindor, V., additional, Herlert, A., additional, Jokinen, A., additional, Khanam, A., additional, Köster, U., additional, Lange, D., additional, Moore, I. D., additional, Müller, M., additional, Mougeot, M., additional, Nesterenko, D. A., additional, Penttilä, H., additional, Petrone, C., additional, Pohjalainen, I., additional, de Roubin, A., additional, Rubchenya, V., additional, Schweiger, Ch., additional, Schweikhard, L., additional, Vilen, M., additional, and Äystö, J., additional

Published
2023
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29. The 41Ar(n,y)42Ar reaction

Author

Sahoo R. N., Paul M., Köster U., Scott R., Tessler M., Zylstra A., Avila M. L., Dickerson C., Jayatissa H., Kohen M.S., McLain J., Pardo R.C., Rehm K. E., Tolstukhin I., Vondrasek R., Bailey T., Callahan L., Clark A., Collon P., Kashiv Y., and Nelson A.

Subjects
Physics, QC1-999
Abstract

The cross-section of the thermal neutron capture 41Ar(n,γ)42Ar(t1/2=32.9 y) reaction was measured by irradiating a 40Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived 42K(12.4 h) β− daughter of 42Ar. Our preliminary value of the 41Ar(n,γ)42Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of 42Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA.

Published
2023
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30. Compton imaging for enhanced sensitivity (n,γ) cross section TOF experiments: Status and prospects

Author

Domingo-Pardo C., Babiano-Suarez V., Balibrea-Correa J., Caballero L., Ladarescu I., Lerendegui-Marco J., Tarifeño-Saldivia A., Aberle O., Alcayne V., Altieri S., Amaducci S., Andrzejewski J., Bacak M., Beltrami C., Bennett S., Bernardes A. P., Berthoumieux E., Beyer R., Boromiza M., Bosnar D., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Casanovas A., Cerutti F., Cescutti G., Chiaveri E., Colombetti P., Colonna N., Console Camprini P., Cortés G., Cortés-Giraldo M. A., Cosentino L., Cristallo S., Dellmann S., Di Castro M., Di Maria S., Diakaki M., Dietz M., Dressler R., Dupont E., Durán I., Eleme Z., Fargier S., Fernández B., Fernández-Domínguez B., Finocchiaro P., Fiore S., García-Infantes F., Gawlik-Ramie˛ga A., Gervino G., Gilardoni S., González-Romero E., Guerrero C., Gunsing F., Gustavino C., Heyse J., Hillman W., Jenkins D. G., Jericha E., Junghans A., Kadi Y., Kaperoni K., Kaur G., Kimura A., Knapová I., Kokkoris M., Köster U., Krtička M., Kyritsis N., Lederer-Woods C., Lerner G., Manna A., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P. M., Mucciola R., Murtas† F., Musacchio-Gonzalez E., Musumarra A., Negret A., Pérez de Rada A., Pérez-Maroto P., Patronis N., Pavón-Rodríguez J. A., Pellegriti M. G., Perkowski J., Petrone C., Pirovano E., Plaza J., Pomp S., Porras I., Praena J., Quesada J. M., Reifarth R., Rochman D., Romanets Y., Rubbia C., Sánchez-Caballero A., Sabaté-Gilarte M., Schillebeeckx P., Schumann D., Sekhar A., Smith A. G., Sosnin N. V., Stamati M. E., Sturniolo A., Tagliente G., Tarrío D., Torres-Sánchez P., Vagena E., Valenta S., Variale V., Vaz P., Vecchio G., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P. J., Wright T., Zarrella R., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Radiative neutron-capture cross sections are of pivotal importance in many fields such as nucle-osynthesis studies or innovative reactor technologies. A large number of isotopes have been measured with high accuracy, but there are still a large number of relevant isotopes whose cross sections could not be experimentally determined yet, at least with sufficient accuracy and completeness, owing to limitations in detection techniques, sample production methods or in the facilities themselves. In the context of the HYMNS (High-sensitivitY Measurements of key stellar Nucleo-Synthesis reactions) project over the last six years we have developed a novel detection technique aimed at background suppression in radiative neutron-capture time-of-flight measurements. This new technique utilizes a complex detection set-up based on position-sensitive radiation-detectors deployed in a Compton-camera array configuration. The latter enables to implement gamma-ray imaging techniques, which help to disentangle true capture events arising from the sample under study and contaminant background events from the surroundings. A summary on the main developments is given in this contribution together with an update on recent experiments at CERN n_TOF and an outlook on future steps.

Published
2023
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31. New measurement of the 235U(nth,f) fission yields and development of a Time of Flight line at the LOHENGRIN spectrometer

Author

Houdouin-Quenault M., Sage C., Méplan O., Ramdhane M., Dauvergne D., Gallin-Martel M.L., Muraz J.F., Guillaudin O., Marcatili S., Kessedjian G., Chebboubi A., Serot O., Litaize O., Bernard D., Köster U., Kim Y.H., Mutti P., and Smith A.G.

Subjects
Physics, QC1-999
Abstract

The study of nuclear fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. In the framework of a collaboration between the CEA, the LPSC and the ILL, a program of actinide fission yield measurements has been ongoing for several years at the LOHENGRIN spectrometer. However, the measurement of very low fission yields in the symmetry region and the heavy wing of the distributions is difficult to achieve due to the strong contamination by other masses with much higher yields and requires the development of a new experimental setup. This paper will first present the results of a new absolute measurement of the 235U(nth,f) mass yields using an ionization chamber placed at the exit of the spectrometer. Although very well documented in the literature, these yields show uncertainties lying from 3% to 10% with large discrepancies between libraries and a lack of correlation matrices. New experimental data obtained at the LOHENGRIN spectrometer will be detailed, along with the measurement method and the production of the experimental covariance matrix. The second part will show the development of a Time of Flight (ToF) line in order to improve the background rejection in the mass yield measurements. In the symmetry region, the precision of the measurement is limited by the background estimation due to the charge exchanges with the residual gas of the separator. We plan to analyze the events using a triple coincidence (∆E x E) x ToF, whereas today only (∆E x E) selection is available. The new ToF line is built using Si3N4 foils and secondary electron detectors (SED) for the start and stop detectors. We will present the choices made for the SED technology along with the progress achieved on the ToF line characterization.

Published
2023
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32. 40Ar proposed as probe of neutron-induced reactions in a high-density stellar-like plasma at the National Ignition Facility

Author

Paul M., Sahoo R. N., Tessler M., Jeet J., Velsko C., Zylstra A., Avila M., Dickerson C., Fougères C., Jayatissa H., Pardo R. C., Rehm K. E., Scott R., Tolstukhin I., Vondrasek R., Bailey T., Callahan L., Clark A. M., Collon P., Kashiv Y., Nelson A., Köster U., Hoffmann H. F. R., Pichotta M., Zuber K., Döring T., and Schwengner R.

Subjects
Physics, QC1-999
Abstract

The thermodynamical conditions and the neutron density produced in a laser-induced implosion of a deuterium-tritium (DT) filled capsule at the National Ignition Facility (NIF) are the closest laboratory analog of stellar conditions. We plan to investigate neutron-induced reactions on 40Ar, namely the 40Ar(n, 2n)39Ar(t1/2 =268 y), the 40Ar(n, γ)41Ar(110 min) and the potential rapid two-neutron capture reaction 40Ar(2n, γ)42Ar(33 y) in an Ar-loaded DT capsule. The chemical inertness of noble gas Ar enables reliable collection of the reaction products.

Published
2023
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34. Synthesis and preclinical evaluation of BOLD-100 radiolabeled with ruthenium-97 and ruthenium-103.

Author

Happl, B., Balber, T., Heffeter, P., Denk, C., Welch, J. M., Köster, U., Alliot, C., Bonraisin, A.-C., Brandt, M., Haddad, F., Sterba, J. H., Kandioller, W., Mitterhauser, M., Hacker, M., Keppler, B. K., and Mindt, T. L.

Subjects
CHOLANGIOCARCINOMA, GASTRIC mucosa, RADIOACTIVE tracers, AUTORADIOGRAPHY, DIAGNOSTIC imaging, SINGLE-photon emission computed tomography
Abstract

BOLD-100 (formerly IT-139, KP1339), a well-established chemotherapeutic agent, is currently being investigated in clinical trials for the treatment of gastric, pancreatic, colorectal, and bile duct cancer. Despite numerous studies, the exact mode of action is still the subject of discussions. Radiolabeled BOLD-100 could be a powerful tool to clarify pharmacokinetic pathways of the compound and to predict therapy responses in patients using nuclear molecular imaging prior to the therapy. In this study, the radiosyntheses of carrier-added (c.a.) [97/103Ru]BOLD-100 were performed with the two ruthenium isotopes ruthenium-103 (103Ru; β−, γ) and ruthenium-97 (97Ru; EC, γ), of which in particular the latter isotope is suitable for imaging by single-photon emission computed tomography (SPECT). To identify the best tumor-to-background ratio for diagnostic imaging, biodistribution studies were performed with two different injected doses of c.a. [103Ru]BOLD-100 (3 and 30 mg kg−1) in Balb/c mice bearing CT26 allografts over a time period of 72 h. Additionally, ex vivo autoradiography of the tumors (24 h p.i.) was conducted. Our results indicate that the higher injected dose (30 mg kg−1) leads to more unspecific accumulation of the compound in non-targeted tissue, which is likely due to an overload of the albumin transport system. It was also shown that lower amounts of injected c.a. [103Ru]BOLD-100 resulted in a relatively higher tumor uptake and, therefore, a better tumor-to-background ratio, which are encouraging results for future imaging studies using c.a. [97Ru]BOLD-100. [ABSTRACT FROM AUTHOR]

Published
2024
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36. Lifetime measurements in 131Sb at LOHENGRIN

Author

Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, Ł. W., additional, Colombi, G., additional, Kim, Y.H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional

Published
2023
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37. Structure of N=56 isotones with 36≤Z≤42 protons

Author

Wiśniewski, J., primary, Urban, W., additional, Rząca-Urban, T., additional, Sieja, K., additional, Blanc, A., additional, Jentschel, M., additional, Micheagnoli, C., additional, Mutti, P., additional, Köster, U., additional, de France, G., additional, Simpson, G. S., additional, and Ur, C. A., additional

Published
2023
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38. In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE

Author

Au, M., primary, Athanasakis-Kaklamanakis, M., additional, Nies, L., additional, Ballof, J., additional, Berger, R., additional, Chrysalidis, K., additional, Fischer, P., additional, Heinke, R., additional, Johnson, J., additional, Köster, U., additional, Leimbach, D., additional, Marsh, B., additional, Mougeot, M., additional, Reich, B., additional, Reilly, J., additional, Reis, E., additional, Schlaich, M., additional, Schweiger, Ch., additional, Schweikhard, L., additional, Stegemann, S., additional, Wessolek, J., additional, Wienholtz, F., additional, Wilkins, S.G., additional, Wojtaczka, W., additional, Düllmann, Ch.E., additional, and Rothe, S., additional

Published
2023
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39. Compton Imaging and Machine-Learning techniques for an enhanced sensitivity in key stellar (n,γ) measurements

Author

Lerendegui-Marco J., Babiano-Suárez V., Balibrea-Correa J., Caballero L., Calvo D., Domingo-Pardo C., Ladarescu I., Real D., Calviño F., Casanovas A., Tarifeño-Saldivia A., Alcayne V., Guerrero C., Millán-Callado M.A., Rodríguez-González T., Barbagallo M., Chiera N.M, Dressler R., Heinitz S., Maugeri E.A, Schumann D., and Köster U.

Subjects
Physics, QC1-999
Abstract

Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant stars. To enhance the sensitivity of such measurements we have developed the i-TED detector. i-TED is an innovative detection system which exploits the Compton imaging technique with the aim of obtaining information about the incoming direction of the detected γ-rays. The imaging capability allows one to reject a large fraction of the dominant γ-ray background, hence enhancing the (n,γ) detection sensitivity. This work summarizes the main results of the first experimental proof-of-concept of the background rejection with i-TED carried out at CERN n_TOF using an early i-TED demonstrator. Two state-of-the-art C6D6 detectors were also used to benchmark the performance of i-TED. The i-TED prototype built for this study shows a factor of ~3 higher detection sensitivity than C6D6 detectors in the ~10 keV neutron-energy range of astrophysical interest. This works also introduces the perspectives of further enhancement in performance attainable with the final i-TED array and new analysis methodologies based on Machine-Learning techniques. The latter provide higher (n,γ) detection efficiency and similar enhancement in the sensitivity than the analytical method based on the Compton scattering law. Finally, we present our proposal to use this detection system for the first time on key astrophysical (n,γ) measurements, in particular on the s-process branching-point 79Se, which is especially well suited to constrain the thermal conditions of Red Giant and Massive Stars.

Published
2022
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40. Low-spin excitations in Zr95

Author

Rząca-Urban, T., primary, Urban, W., additional, Blanc, A., additional, Jentschel, M., additional, Mutti, P., additional, Köster, U., additional, de France, G., additional, Simpson, G. S., additional, and Ur, C. A., additional

Published
2023
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41. Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons

Author

Au, M., primary, Athanasakis-Kaklamanakis, M., additional, Nies, L., additional, Heinke, R., additional, Chrysalidis, K., additional, Köster, U., additional, Kunz, P., additional, Marsh, B., additional, Mougeot, M., additional, Schweikhard, L., additional, Stegemann, S., additional, Vila Gracia, Y., additional, Düllmann, Ch. E., additional, and Rothe, S., additional

Published
2023
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42. Core-proton coupled nature of the 11/2+ state in 131 Sb probed by lifetime measurements

Author

Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, L. W., additional, Colombi, G., additional, Kim, Y.H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional

Published
2023
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43. 40Ar proposed as probe of neutron-induced reactions in a high-density stellar-like plasma at the National Ignition Facility

Author

Paul, M., Sahoo, S. N., Tessler, M., Jeet, J., Velsko, C., Zylstra, A., Avila, M., Dickerson, C., Fougeres, C., Jayatissa, H., Pardo, R. C., Rehm, K. E., Scott, R., Toltsukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A. M., Collon, P., Kashiv, Y., Nelson, A., Köster, U., Hoffmann, H. F. R., Pichotta, M., Zuber, K., Döring, T., (0000-0002-7620-8882) Schwengner, R., Paul, M., Sahoo, S. N., Tessler, M., Jeet, J., Velsko, C., Zylstra, A., Avila, M., Dickerson, C., Fougeres, C., Jayatissa, H., Pardo, R. C., Rehm, K. E., Scott, R., Toltsukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A. M., Collon, P., Kashiv, Y., Nelson, A., Köster, U., Hoffmann, H. F. R., Pichotta, M., Zuber, K., Döring, T., and (0000-0002-7620-8882) Schwengner, R.

Abstract

The thermodynamical conditions of plasma density, temperature, pressure and the neutron density produced in a laser-induced implosion of a deuterium-tritium (DT) filled capsule at the National Ignition Facility (NIF) are the closest laboratory analog of stellar conditions. We plan to investigate neutron-induced reactions on 40Ar, namely the 40Ar(n, 2n)39Ar(t1/2 =268 y), the 40Ar(n,gamma)41Ar(110 min) and the potential rapid two-neutron capture reaction 40Ar(2n,gamma)42Ar(33 y) in the same implosion on an Ar-loaded DT capsule. The chemical inertness of noble gas Ar enables reliable collection of the reaction products. We describe here the technique of Noble-Gas Accelerator Mass Spectrometry (NOGAMS) to be used for ultra-sensitive detection of the long-lived 39Ar and 42Ar at Argonne National Laboratory. A 42Ar(33 y) sample was produced via the slow two-neutron capture reaction 40Ar(2n, gamma)42Ar in a high thermal-neutron flux irradiation. 39Ar and for the first time 42Ar atoms were directly detected in the abundance range 10^-12 -- 10^-13 . The present sensitivity of 42Ar detection is of the order of 104 atoms.

Published
2023

44. New measurement of the 235U(nth,f) fission yields and development of a Time of Flight line at the LOHENGRIN spectrometer.

Author

Houdouin-Quenault, M., Sage, C., Méplan, O., Ramdhane, M., Dauvergne, D., Gallin-Martel, M.L., Muraz, J.F., Guillaudin, O., Marcatili, S., Kessedjian, G., Chebboubi, A., Serot, O., Litaize, O., Bernard, D., Köster, U., Kim, Y.H., Mutti, P., and Smith, A.G.

Subjects
NUCLEAR fission, TIME-of-flight spectrometers, NUCLEAR reactors, ACTINIDE elements, COVARIANCE matrices
Abstract

The study of nuclear fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. In the framework of a collaboration between the CEA, the LPSC and the ILL, a program of actinide fission yield measurements has been ongoing for several years at the LOHENGRIN spectrometer. However, the measurement of very low fission yields in the symmetry region and the heavy wing of the distributions is difficult to achieve due to the strong contamination by other masses with much higher yields and requires the development of a new experimental setup. This paper will first present the results of a new absolute measurement of the 235U(nth,f) mass yields using an ionization chamber placed at the exit of the spectrometer. Although very well documented in the literature, these yields show uncertainties lying from 3% to 10% with large discrepancies between libraries and a lack of correlation matrices. New experimental data obtained at the LOHENGRIN spectrometer will be detailed, along with the measurement method and the production of the experimental covariance matrix. The second part will show the development of a Time of Flight (ToF) line in order to improve the background rejection in the mass yield measurements. In the symmetry region, the precision of the measurement is limited by the background estimation due to the charge exchanges with the residual gas of the separator. We plan to analyze the events using a triple coincidence (∆E x E) x ToF, whereas today only (∆E x E) selection is available. The new ToF line is built using Si3N4 foils and secondary electron detectors (SED) for the start and stop detectors. We will present the choices made for the SED technology along with the progress achieved on the ToF line characterization. [ABSTRACT FROM AUTHOR]

Published
2023
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45. The 41Ar(n,y)42Ar reaction.

Author

Sahoo, R. N., Paul, M., Köster, U., Scott, R., Tessler, M., Zylstra, A., Avila, M. L., Dickerson, C., Jayatissa, H., Kohen, M.S., McLain, J., Pardo, R.C., Rehm, K. E., Tolstukhin, I., Vondrasek, R., Bailey, T., Callahan, L., Clark, A., Collon, P., and Kashiv, Y.

Subjects
NUCLEAR cross sections, THERMAL neutron capture, ARGON isotopes, NUCLEAR reactors, MASS spectrometry
Abstract

The cross-section of the thermal neutron capture 41Ar(n,γ)42Ar(t1/2=32.9 y) reaction was measured by irradiating a 40Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived 42K(12.4 h) β− daughter of 42Ar. Our preliminary value of the 41Ar(n,γ)42Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of 42Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA. [ABSTRACT FROM AUTHOR]

Published
2023
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46. Testing the predictive power of realistic shell model calculations via lifetime measurement of the 11/2+ state in Sb131

Author

Bottoni, S., primary, Gamba, E. R., additional, De Gregorio, G., additional, Gargano, A., additional, Leoni, S., additional, Fornal, B., additional, Brancadori, N., additional, Ciconali, G., additional, Crespi, F. C. L., additional, Cieplicka-Oryńczak, N., additional, Iskra, Ł. W., additional, Colombi, G., additional, Kim, Y. H., additional, Köster, U., additional, Michelagnoli, C., additional, Dunkel, F., additional, Esmaylzadeh, A., additional, Gerhard, L., additional, Jolie, J., additional, Knafla, L., additional, Ley, M., additional, Régis, J.-M., additional, Schomaker, K., additional, and Sferrazza, M., additional

Published
2023
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47. First measurement of the 94Nb(n,γ) cross section at the CERN n_TOF facility

Author

Balibrea-Correa, J., primary, Babiano-Suárez, V., additional, Lerendegui-Marco, J., additional, Domingo-Pardo, C., additional, Ladarescu, I., additional, Tarifeño-Saldivia, A., additional, Alcayne, V., additional, Cano-Ott, D., additional, González-Romero, E., additional, Martínez, T., additional, Mendoza, E., additional, Guerrero, C., additional, Calviño, F., additional, Casanovas, A., additional, Köster, U., additional, Chiera, N. M., additional, Dressler, R., additional, Maugeri, E. A., additional, Schumann, D., additional, Aberle, O., additional, Altieri, S., additional, Amaducci, S., additional, Andrzejewski, J., additional, Bacak, M., additional, Beltrami, C., additional, Bennett, S., additional, Bernardes, A. P., additional, Berthoumieux, E., additional, Beyer, R., additional, Boromiza, M., additional, Bosnar, D., additional, Caamaño, M., additional, Calviani, M., additional, Cerutti, F., additional, Cescutti, G., additional, Chiaveri, E., additional, Colombetti, P., additional, Colonna, N., additional, Console Camprini, P., additional, Cortés, G., additional, Cortés-Giraldo, M. A., additional, Cosentino, L., additional, Cristallo, S., additional, Dellmann, S., additional, Di Castro, M., additional, Di Maria, S., additional, Diakaki, M., additional, Dietz, M., additional, Dupont, E., additional, Durán, I., additional, Eleme, Z., additional, Fargier, S., additional, Fernández, B., additional, Fernández-Domínguez, B., additional, Finocchiaro, P., additional, Fiore, S., additional, García-Infantes, F., additional, Gawlik-Ramięga, A., additional, Gervino, G., additional, Gilardoni, S., additional, Gunsing, F., additional, Gustavino, C., additional, Heyse, J., additional, Hillman, W., additional, Jenkins, D. G., additional, Jericha, E., additional, Junghans, A., additional, Kadi, Y., additional, Kaperoni, K., additional, Kaur, G., additional, Kimura, A., additional, Knapová, I., additional, Kokkoris, M., additional, Krtička, M., additional, Kyritsis, N., additional, Lederer-Woods, C., additional, Lerner, G., additional, Manna, A., additional, Masi, A., additional, Massimi, C., additional, Mastinu, P., additional, Mastromarco, M., additional, Mazzone, A., additional, Mengoni, A., additional, Michalopoulou, V., additional, Milazzo, P. M., additional, Mucciola, R., additional, Murtas, F., additional, Musacchio-Gonzalez, E., additional, Musumarra, A., additional, Negret, A., additional, Pérez de Rada, A., additional, Pérez-Maroto, P., additional, Patronis, N., additional, Pavón-Rodríguez, J. A., additional, Pellegriti, M. G., additional, Perkowski, J., additional, Petrone, C., additional, Pirovano, E., additional, Plaza, J., additional, Pomp, S., additional, Porras, I., additional, Praena, J., additional, Quesada, J. M., additional, Reifarth, R., additional, Rochman, D., additional, Romanets, Y., additional, Rubbia, C., additional, Sánchez-Caballero, A., additional, Sabaté-Gilarte, M., additional, Schillebeeckx, P., additional, Sekhar, A., additional, Smith, A. G., additional, Sosnin, N. V., additional, Stamati, M. E., additional, Sturniolo, A., additional, Tagliente, G., additional, Tarrío, D., additional, Torres-Sánchez, P., additional, Vagena, E., additional, Valenta, S., additional, Variale, V., additional, Vaz, P., additional, Vecchio, G., additional, Vescovi, D., additional, Vlachoudis, V., additional, Vlastou, R., additional, Wallner, A., additional, Woods, P. J., additional, Wright, T., additional, Zarrella, R., additional, and Žugec, P., additional

Published
2023
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48. New detection systems for an enhanced sensitivity in key stellar (n,γ) measurements

Author

Lerendegui-Marco, J., primary, Babiano-Suárez, V., additional, Balibrea-Correa, J., additional, Domingo-Pardo, C., additional, Ladarescu, I., additional, Tarifeño-Saldivia, A., additional, Alcayne, V., additional, Cano-Ott, D., additional, González-Romero, E., additional, Martínez, T., additional, Mendoza, E., additional, Guerrero, C., additional, Calviño, F., additional, Casanovas, A., additional, Köster, U., additional, Chiera, N. M., additional, Dressler, R., additional, Maugeri, E. A., additional, Schumann, D., additional, Aberle, O., additional, Altieri, S., additional, Amaducci, S., additional, Andrzejewski, J., additional, Bacak, M., additional, Beltrami, C., additional, Bennett, S., additional, Bernardes, A. P., additional, Berthoumieux, E., additional, Beyer, R., additional, Boromiza, M., additional, Bosnar, D., additional, Caamaño, M., additional, Calviani, M., additional, Cerutti, F., additional, Cescutti, G., additional, Chiaveri, E., additional, Colombetti, P., additional, Colonna, N., additional, Console Camprini, P., additional, Cortés, G., additional, Cortés-Giraldo, M. A., additional, Cosentino, L., additional, Cristallo, S., additional, Dellmann, S., additional, Di Castro, M., additional, Di Maria, S., additional, Diakaki, M., additional, Dietz, M., additional, Dupont, E., additional, Durán, I., additional, Eleme, Z., additional, Fargier, S., additional, Fernández, B., additional, Fernández-Domínguez, B., additional, Finocchiaro, P., additional, Fiore, S., additional, García-Infantes, F., additional, Gawlik-Ramięga, A., additional, Gervino, G., additional, Gilardoni, S., additional, Gunsing, F., additional, Gustavino, C., additional, Heyse, J., additional, Hillman, W., additional, Jenkins, D. G., additional, Jericha, E., additional, Junghans, A., additional, Kadi, Y., additional, Kaperoni, K., additional, Kaur, G., additional, Kimura, A., additional, Knapová, I., additional, Kokkoris, M., additional, Krtička, M., additional, Kyritsis, N., additional, Lederer-Woods, C., additional, Lerner, G., additional, Manna, A., additional, Masi, A., additional, Massimi, C., additional, Mastinu, P., additional, Mastromarco, M., additional, Mazzone, A., additional, Mengoni, A., additional, Michalopoulou, V., additional, Milazzo, P. M., additional, Mucciola, R., additional, Murtas, F., additional, Musacchio-Gonzalez, E., additional, Musumarra, A., additional, Negret, A., additional, Pérez de Rada, A., additional, Pérez-Maroto, P., additional, Patronis, N., additional, Pavón-Rodríguez, J. A., additional, Pellegriti, M. G., additional, Perkowski, J., additional, Petrone, C., additional, Pirovano, E., additional, Plaza, J., additional, Pomp, S., additional, Porras, I., additional, Praena, J., additional, Quesada, J. M., additional, Reifarth, R., additional, Rochman, D., additional, Romanets, Y., additional, Rubbia, C., additional, Sánchez-Caballero, A., additional, Sabaté-Gilarte, M., additional, Schillebeeckx, P., additional, Sekhar, A., additional, Smith, A. G., additional, Sosnin, N. V., additional, Stamati, M. E., additional, Sturniolo, A., additional, Tagliente, G., additional, Tarrío, D., additional, Torres-Sánchez, P., additional, Vagena, E., additional, Valenta, S., additional, Variale, V., additional, Vaz, P., additional, Vecchio, G., additional, Vescovi, D., additional, Vlachoudis, V., additional, Vlastou, R., additional, Wallner, A., additional, Woods, P. J., additional, Wright, T., additional, Zarrella, R., additional, and Žugec, P., additional

Published
2023
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49. First measurement of the 94Nb(n,γ) cross section at the CERN n_TOF facility.

Author

Balibrea-Correa, J., Babiano-Suárez, V., Lerendegui-Marco, J., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., Guerrero, C., Calviño, F., Casanovas, A., Köster, U., Chiera, N. M., Dressler, R., Maugeri, E. A., Schumann, D., and Aberle, O.

Subjects
NEUTRON capture, ISOTOPES, NUCLEAR astrophysics, NUCLEOSYNTHESIS, NUCLEAR reactions
Abstract

One of the crucial ingredients for the improvement of stellar models is the accurate knowledge of neutron capture cross-sections for the different isotopes involved in the s-,r- and i- processes. These measurements can shed light on existing discrepancies between observed and predicted isotopic abundances and help to constrain the physical conditions where these reactions take place along different stages of stellar evolution. In the particular case of the radioactive 94Nb, the 94Nb(n,γ) cross-section could play a role in the determination of the s-process production of 94Mo in AGB stars, which presently cannot be reproduced by state-of-the-art stellar models. There are no previous 94Nb(n,γ) experimental data for the resolved and unresolved resonance regions mainly due to the difficulties in producing highquality samples and also due to limitations in conventional detection systems commonly used in time-of-flight experiments. Motivated by this situation, a first measurement of the 94Nb(n,γ) reaction was carried out at CERN n_TOF, thereby exploiting the high luminosity of the EAR2 area in combination with a new detection system of small-volume C6D6-detectors and a high quality 94Nb-sample. The latter was based on hyper-pure 93Nb material activated at the high-flux reactor of ILL-Grenoble. An innovative ring-configuration detection system in close geometry around the capture sample allowed us to significantly enhance the signal-to-background ratio. This set-up was supplemented with two conventional C6D6-detectors and a highresolution LaCl3(Ce)-detector, which will be employed for addressing reliably systematic effects and uncertainties. At the current status of the data analysis, 18 resonance in 94Nb+n have been observed for the first time in the neutron energy range from thermal up to 10 keV. [ABSTRACT FROM AUTHOR]

Published
2023
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50. Lifetimes and transition probabilities for low-lying yrast levels in Te130,132

Author

Kumar, D., primary, Bhattacharjee, T., additional, Alam, S. S., additional, Basak, S., additional, Gerhard, L., additional, Knafla, L., additional, Esmaylzadeh, A., additional, Ley, M., additional, Dunkel, F., additional, Schomaker, K., additional, Régis, J. -M., additional, Jolie, J., additional, Kim, Y. H., additional, Köster, U., additional, Simpson, G. S., additional, and Fraile, L. M., additional

Published
2022
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