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2,701 results on '"Langer C."'

1. Proton capture on stored radioactive 118Te ions

Author

Dellmann S. F., Glorius J., Litvinov Y. A., Reifarth R., Al-Khasawneh K., Aliotta M., Bott L., Brückner B., Bruno C., Chen R. J., Davinson T., Dickel T., Dillmann I, Dmytriev D., Erbacher P., Freire-Fernández D., Forstner O., Geissel H., Göbel K., Griffin C. J., Grisenti R., Gumberidze A., Haettner E., Hagmann S., Heil M., Heß R., Hillenbrand P.-M., Joseph R., Jurado B., Kozhuharov C., Kulikov I., Löher B., Langer C., Leckenby G., Lederer-Woods C., Lestinsky M., Litvinov S., Lorenz B. A., Lorenz E., Marsh J., Menz E., Morgenroth T., Petridis N., Pibernat J., Popp U., Psaltis A., Sanjari S., Scheidenberger C., Sguazzin M., Sidhu R. S., Spillmann U., Steck M., Stöhlker T., Surzhykov A., Swartz J. A., Törnqvist H., Varga L., Vescovi D., Weick H., Weigand M., Woods P., Xing Y., and Yamaguchi T.

Subjects
Physics, QC1-999
Abstract

Experimental determination of the cross sections of proton capture on radioactive nuclei is extremely difficult. Therefore, it is of substantial interest for the understanding of the production of the p-nuclei. For the first time, a direct measurement of proton-capture cross sections on stored, radioactive ions became possible in an energy range of interest for nuclear astrophysics. The experiment was performed at the Experimental Storage Ring (ESR) at GSI by making use of a sensitive method to measure (p,γ) and (p,n) reactions in inverse kinematics. These reaction channels are of high relevance for the nucleosyn-thesis processes in supernovae, which are among the most violent explosions in the universe and are not yet well understood. The cross section of the 118Te(p,γ) reaction has been measured at energies of 6 MeV/u and 7 MeV/u. The heavy ions interacted with a hydrogen gas jet target. The radiative recombination process of the fully stripped 118Te ions and electrons from the hydrogen target was used as a luminosity monitor. An overview of the experimental method and preliminary results from the ongoing analysis will be presented.

Published
2023
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2. Storage, Accumulation and Deceleration of Secondary Beams for Nuclear Astrophysics

Author

Glorius, J., Litvinov, Yu. A., Aliotta, M., Amjad, F., Brückner, B., Bruno, C. G., Chen, R., Davinson, T., Dellmann, S. F., Dickel, T., Dillmann, I., Erbacher, P., Forstner, O., Geissel, H., Griffin, C. J., Grisenti, R., Gumberidze, A., Haettner, E., Hess, R., Hillenbrand, P. -M., Hornung, C., Joseph, R., Jurado, B., Kazanseva, E., Knöbel, R., Kostyleva, D., Kozhuharov, C., Kuzminchuk, N., Langer, C., Leckenby, G., Lederer-Woods, C., Lestinsky, M., Litvinov, S., Löher, B., Lorenz, B., Lorenz, E., Marsh, J., Menz, E., Morgenroth, T., Mukha, I., Petridis, N., Popp, U., Psaltis, A., Purushothaman, S., Reifarth, R., Rocco, E., Roy, P., Sanjari, M. S., Scheidenberger, C., Sguazzin, M., Sidhu, R. S., Spillmann, U., Steck, M., Stöhlker, T., Swartz, J. A., Tanaka, Y. K., Törnqvist, H., Varga, L., Vescovi, D., Weick, H., Weigand, M., Woods, P. J., Yamaguchi, T., and Zhao, J.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

Low-energy investigations on rare ion beams are often limited by the available intensity and purity of the ion species in focus. Here, we present the first application of a technique that combines in-flight production at relativistic energies with subsequent secondary beam storage, accumulation and finally deceleration to the energy of interest. Using the FRS and ESR facilities at GSI, this scheme was pioneered to provide a secondary beam of $^{118}$Te$^{52+}$ for the measurement of nuclear proton-capture at energies of 6 and 7 MeV/u. The technique provided stored beam intensities of about $10^6$ ions at high purity and brilliance, representing a major step towards low-energy nuclear physics studies using rare ion beams.

Published
2023
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3. High-precision mass measurement of $^{24}$Si and a refined determination of the $rp$ process at the $A=22$ waiting point

Author

Puentes, D., Meisel, Z., Bollen, G., Hamaker, A., Langer, C., Leistenschneider, E., Nicoloff, C., Ong, W. -J., Redshaw, M., Ringle, R., Sumithrarachchi, C. S., Surbrook, J., Valverde, A. A., and Yandow, I. T.

Subjects
Nuclear Experiment
Abstract

We report a high precision mass measurement of $^{24}{\rm Si}$, performed with the LEBIT facility at the National Superconducting Cyclotron Laboratory. The atomic mass excess, $10\;753.8$(37) keV, is a factor of 5 more precise than previous results. This substantially reduces the uncertainty of the $^{23}{\rm Al}(p,\gamma)^{24}{\rm Si}$ reaction rate, which is a key part of the rapid proton capture ($rp$) process powering Type I X-ray bursts. The updated rate constrains the onset temperature of the $(\alpha,p)$ process at the $^{22}{\rm Mg}$ waiting-point to a precision of 9%., Comment: 6 pages, 3 figures

Published
2022
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4. High precision measurement of the radiative capture cross section of 238U at the n_TOF CERN facility

Author

Mingrone F., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Barbagallo M., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calviño F., Calviani M., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Durán I., Eleftheriadis C., Ferrari A., Fraval K., Furman V., Göbel K., Gómez-Hornillos M.B., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Heftrich T., Hernández-Prieto A., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Karadimos D., Katabuchi T., Ketlerov V., Khryachkov V., Kivel N., Koehler P., Kokkoris M., Kroll J., Krtička M., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Lerendegui-Marco J., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Mendoza E., Mengoni A., Milazzo P.M., Mirea M., Mondelaers W., Paradela C., Pavlik A., Perkowski J., Plompen A.J.M., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiss C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ) cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n_TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented.

Published
2017
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5. The Nuclear Astrophysics program at n_TOF (CERN)

Author

Colonna N., Aberle O., Andrzejewski J., Audouin L., Bacak M., Balibrea J., Barbagallo M., Bečvář F., Berthoumieux E., Billowes J., Bosnar D., Brown A., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Cerutti F., Chen Y. H., Chiaveri E., Clai G., Cortés G., Cortés-Giraldo M. A., Cosentino, Cristallo S., Damone L. A., Diakaki M., Domingo-Pardo C., Dressler L. R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Göbel K., García A. R., Gawlik A., Gilardoni S., Glodariu T., Gonçalves I. F., González E., Griesmayer E., Guerrero C., Gunsing F., Harada H., Heinitz S., Hernandez-Prieto A., Heyse J., Jenkins D. G., Jericha E., Käppeler F., Kadi Y., Kalamara A., Kavrigin P., Kimura A., Kivel N., Kokkoris M., Kroll J., Krtička M., Kurtulgil D., Langer C., Leal-Cidoncha E., Lederer C., Lerendegui-Marco J., Leeb H., Lo Meo S., Lonsdale S. J., Losito S., Macina D., Mallik A., Marganiec J., Martínez T., Masi A., Massimi C., Mastinu P., Mastromarco M., Maugeri E. A., Mazzone A., Mendoza E., Mengoni A., Mingrone F., Milazzo P. M., Mirea M., Musumarra A., Negret A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J. M., Radeck D., Rauscher T., Reifarth R., Riego A., Robles M.S., Rubbia C., Ryan J. A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Sedyshev P., Smith A. G., Sosnin N. V., Stamatopoulos A., Tagliente G., Tain J. L., Tarifeño-Saldivia A., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Vlastou R., Wallner A., Warren S., Weiss C., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis. Several neutron capture reactions relevant to s-process nucleosynthesis have been measured so far, some of which on important branching point radioisotopes. Furthermore, the construction of a second experimental area has recently opened the way to challenging measurements of (n, charged particle) reactions on isotopes of short half-life. The Nuclear Astrophysics program of the n_TOF Collaboration is here described, with emphasis on recent results relevant for stellar nucleosynthesis, stellar neutron sources and primordial nucleosynthesis.

Published
2017
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6. Measurement of the neutron capture cross section of the fissile isotope 235U with the CERN n_TOF total absorption calorimeter and a fission tagging based on micromegas detectors

Author

Balibrea-Correa J., Mendoza E., Cano-Ott D., Krtička M., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Barbagallo M., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calviño F., Calviani M., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Durán I., Eleftheriadis C., Ferrari A., Fraval K., Furman V., Göbel K., Guerrero C., Gómez-Hornillos M.B., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Gunsing F., Heftrich T., Heinitz S., Hernández-Prieto A., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Karadimos D., Katabuchi T., Ketlerov V., Khryachkov V., Kivel N., Koehler P., Kokkoris M., Kroll J., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Lerendegui-Marco J., Licata M., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Paradela C., Pavlik A., Perkowski J., Plompen A.J.M., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiss C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The accuracy on neutron capture cross section of fissile isotopes must be improved for the design of future nuclear systems such as Gen-IV reactors and Accelerator Driven Systems. The High Priority Request List of the Nuclear Energy Agency, which lists the most important nuclear data requirements, includes also the neutron capture cross sections of fissile isotopes such as 233,235U and 239,241Pu. A specific experimental setup has been used at the CERN n_TOF facility for the measurement of the neutron capture cross section of 235U by a set of micromegas fission detectors placed inside a segmented BaF2 Total Absorption Calorimeter.

Published
2017
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7. High accuracy 234U(n,f) cross section in the resonance energy region

Author

Leal-Cidoncha E., Durán I., Paradela C., Tassan-Got L., Audouin L., Leal L.C., Naour C. Le, Noguere G., Tarrío D., Leong L.S., Altstadt S., Andrzejewski J., Barbagallo M., Bécares V., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gómez-Hornillos M.B., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Kokkoris M., Krtička M., Kroll J., Lampoudis C., Langer C., Lederer C., Leeb H., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P.F., Mastromarco M., Meaze M., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Robles M.S., Roman F., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n_TOF data [1], has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n_TOF neutron flux.

Published
2017
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8. Measurement of the 241Am neutron capture cross section at the n_TOF facility at CERN

Author

Mendoza E., Cano-Ott D., Altstadt S., Andriamonje S., Andrzejewski J., Audouin L., Balibrea J., Bécares V., Barbagallo M., Bečvář F., Belloni F., Berthier B., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calviño F., Calviani M., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Dillmann I., Domingo-Pardo C., Durán I., Dzysiuk N., Eleftheriadis C., Fernández-Ordóñez M., Ferrari A., Fraval K., Furman V., Gómez-Hornillos M.B., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González E., Goverdovski A., Gramegna F., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Heftrich T., Heinitz S., Hernández-Prieto A., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Karadimos D., Katabuchi T., Ketlerov V., Khryachkov V., Koehler P., Kokkoris M., Kroll J., Krtička M., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Lerendegui-Marco J., Licata M., Losito R., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Paradela C., Pavlik A., Perkowski J., Plompen A.J.M., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Roman F., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vermeulen M.J., Versaci R., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiss C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

New neutron cross section measurements of minor actinides have been performed recently in order to reduce the uncertainties in the evaluated data, which is important for the design of advanced nuclear reactors and, in particular, for determining their performance in the transmutation of nuclear waste. We have measured the 241Am(n,γ) cross section at the n_TOF facility between 0.2 eV and 10 keV with a BaF2 Total Absorption Calorimeter, and the analysis of the measurement has been recently concluded. Our results are in reasonable agreement below 20 eV with the ones published by C. Lampoudis et al. in 2013, who reported a 22% larger capture cross section up to 110 eV compared to experimental and evaluated data published before. Our results also indicate that the 241Am(n,γ) cross section is underestimated in the present evaluated libraries between 20 eV and 2 keV by 25%, on average, and up to 35% for certain evaluations and energy ranges.

Published
2017
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9. Dissemination of data measured at the CERN n_TOF facility

Author

Dupont E., Otuka N., Cabellos O., Aberle O., Aerts G., Altstadt S., Alvarez H., Alvarez-Velarde F., Andriamonje S., Andrzejewski J., Audouin L., Bacak M., Badurek G., Balibrea J., Barbagallo M., Barros S., Baumann P., Bécares V., Bečvář F., Beinrucker C., Belloni F., Berthier B., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brown A., Brugger M., Caamaño M., Calviani M., Calviño F., Cano-Ott D., Capote R., Cardella R., Carrapiço C., Casanovas A., Castelluccio D.M., Cennini P., Cerutti F., Chen Y.H., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Cosentino L., Couture A., Cox J., Damone L.A., David S., Deo K., Diakaki M., Dillmann I., Domingo-Pardo C., Dressler R., Dridi W., Duran I., Eleftheriadis C., Embid-Segura M., Fernández-Domínguez B., Ferrant L., Ferrari A., Ferreira P., Finocchiaro P., Fraval K., Frost R.J.W., Fujii K., Furman W., Ganesan S., Garcia A.R., Gawlik A., Gheorghe I., Gilardoni S., Giubrone G., Glodariu T., Göbel K., Gomez-Hornillos M.B., Goncalves I.F., Gonzalez-Romero E., Goverdovski A., Gramegna F., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Haight R., Harada H., Heftrich T., Heil M., Heinitz S., Hernández-Prieto A., Heyse J., Igashira M., Isaev S., Jenkins D.G., Jericha E., Kadi Y., Kaeppeler F., Kalamara A., Karadimos D., Karamanis D., Katabuchi T., Kavrigin P., Kerveno M., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Konovalov V., Krtička M., Kroll J., Kurtulgil D., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Naour C. Le, Lerendegui-Marco J., Leong L.S., Licata M., Meo S. Lo, Lonsdale S.J., Losito R., Lozano M., Macina D., Manousos A., Marganiec J., Martinez T., Marrone S., Masi A., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E.A., Mazzone A., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Montesano S., Moreau C., Mosconi M., Musumarra A., Negret A., Nolte R., O’Brien S., Oprea A., Palomo-Pinto F.R., Pancin J., Paradela C., Patronis N., Pavlik A., Pavlopoulos P., Perkowski J., Perrot L., Pigni M.T., Plag R., Plompen A., Plukis L., Poch A., Porras I., Praena J., Pretel C., Quesada J.M., Radeck D., Rajeev K., Rauscher T., Reifarth R., Riego A., Robles M., Roman F., Rout P.C., Rudolf G., Rubbia C., Rullhusen P., Ryan J.A., Sabaté-Gilarte M., Salgado J., Santos C., Sarchiapone L., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A.G., Sosnin N.V., Stamatopoulos A., Stephan C., Suryanarayana S.V., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tarrío D., Tassan-Got L., Tavora L., Terlizzi R., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Villamarin D., Vicente M.C., Vlachoudis V., Vlastou R., Voss F., Wallner A., Walter S., Ware T., Warren S., Weigand M., Weiß C., Wolf C., Wiesher M., Wisshak K., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The n_TOF neutron time-of-flight facility at CERN is used for high quality nuclear data measurements from thermal energy up to hundreds of MeV. In line with the CERN open data policy, the n_TOF Collaboration takes actions to preserve its unique data, facilitate access to them in standardised format, and allow their re-use by a wide community in the fields of nuclear physics, nuclear astrophysics and various nuclear technologies. The present contribution briefly describes the n_TOF outcomes, as well as the status of dissemination and preservation of n_TOF final data in the international EXFOR library.

Published
2017
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10. The 236U neutron capture cross-section measured at the n_TOF CERN facility

Author

Mastromarco M., Barbagallo M., Vermeulen M.J., Colonna N., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Calviño F., Calviani M., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Durán I., Dzysiuk N., Eleftheriadis C., Ferrari A., Fraval K., Furman V., Gómez-Hornillos M.B., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Heftrich T., Heinitz S., Hernández-Prieto A., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Karadimos D., Katabuchi T., Ketlerov V., Khryachkov V., Koehler P., Kokkoris M., Kroll J., Krtička M., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Lerendegui-Marco J., Licata M., Losito R., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Paradela C., Pavlik A., Perkowski J., Plompen A.J.M., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Roman F., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiss C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The 236U isotope plays an important role in nuclear systems, both for future and currently operating ones. The actual knowledge of the capture reaction of this isotope is satisfactory in the thermal region, but it is considered insufficient for Fast Reactor and ADS applications. For this reason the 236U(n, γ) reaction cross-section has been measured for the first time in the whole energy region from thermal energy up to 1 MeV at the n_TOF facility with two different detection systems: an array of C6D6 detectors, employing the total energy deposited method, and a FX1 total absorption calorimeter (TAC), made of 40 BaF2 crystals. The two n_TOF data sets agree with each other within the statistical uncertainty in the Resolved Resonance Region up to 800 eV, while sizable differences (up to ≃ 20%) are found relative to the current evaluated data libraries. Moreover two new resonances have been found in the n_TOF data. In the Unresolved Resonance Region up to 200 keV, the n_TOF results show a reasonable agreement with previous measurements and evaluated data.

Published
2017
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11. In-beam $\gamma$-ray spectroscopy of $^{32}$Mg via direct reactions

Author

Kitamura, N., Wimmer, K., Miyagi, T., Poves, A., Shimizu, N., Tostevin, J. A., Bader, V. M., Bancroft, C., Barofsky, D., Baugher, T., Bazin, D., Berryman, J. S., Bildstein, V., Gade, A., Imai, N., Kröll, T., Langer, C., Lloyd, J., Lunderberg, E., Nowacki, F., Perdikakis, G., Recchia, F., Redpath, T., Saenz, S., Smalley, D., Stroberg, S. R., Utsuno, Y., Weisshaar, D., and Westerberg, A.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Background: The nucleus $^{32}$Mg ($N=20$ and $Z=12$) plays a central role in the so-called "island of inversion" where in the ground states $sd$-shell neutrons are promoted to the $fp$-shell orbitals across the shell gap, resulting in the disappearance of the canonical neutron magic number $N=20$. Purpose: The primary goals of this work are to extend the level scheme of $^{32}$Mg, provide spin-parity assignments to excited states, and discuss the microscopic structure of each state through comparisons with theoretical calculations. Method: In-beam $\gamma$-ray spectroscopy of $^{32}$Mg was performed using two direct-reaction probes, one-neutron (two-proton) knockout reactions on $^{33}$Mg ($^{34}$Si). Final-state exclusive cross sections and parallel momentum distributions were extracted from the experimental data and compared with eikonal-based reaction model calculations combined with shell-model overlap functions. Results: Owing to the remarkable selectivity of the one-neutron and two-proton knockout reactions, a significantly updated level scheme for $^{32}$Mg, which exhibits negative-parity intruder and positive-parity normal states, was constructed. The experimental results were confronted with four different nuclear structure models. Conclusions: In some of these models, different aspects of $^{32}$Mg and the transition into the island of inversion are well described. However, unexplained discrepancies remain, and even with the help of these state-of-the-art theoretical approaches, the structure of this key nucleus is not yet fully captured.

Published
2022
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12. Fission Fragment Angular Distribution measurements of 235U and 238U at CERN n_TOF facility

Author

Leal-Cidoncha E., Durán I., Paradela C., Tarrío D., Leong L.S., Tassan-Got L., Audouin L., Altstadt S., Andrzejewski J., Barbagallo M., Bécares V., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Dzysiuk N., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gómez-Hornillos M.B., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Koehler P., Kokkoris M., Krtička M., Kroll J., Lampoudis C., Langer C., Lederer C., Leeb H., Lo Meo S., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P.F., Mastromarco M., Meaze M., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Robles M.S., Roman F., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Neutron-induced fission cross sections of 238U and 235U are used as standards in the fast neutron region up to 200 MeV. A high accuracy of the standards is relevant to experimentally determine other neutron reaction cross sections. Therefore, the detection effciency should be corrected by using the angular distribution of the fission fragments (FFAD), which are barely known above 20 MeV. In addition, the angular distribution of the fragments produced in the fission of highly excited and deformed nuclei is an important observable to investigate the nuclear fission process. In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs) has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new 235U(n,f) and 238U(n,f) data in the extended energy range up to 200 MeV compared to the existing experimental data.

Published
2016
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13. Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN – n_TOF

Author

Diakaki M., Audouin L., Berthoumieux E., Calviani M., Colonna N., Dupont E., Duran I., Gunsing F., Leal-Cidoncha E., Le Naour C., Leong L.S., Mastromarco M., Paradela C., Tarrio D., Tassan-Got L., Aerts G., Altstadt S., Alvarez H., Alvarez-Velarde F., Andriamonje S., Andrzejewski J., Badurek G., Barbagallo M., Baumann P., Becares V., Becvar F., Belloni F., Berthier B., Billowes J., Boccone V., Bosnar D., Brugger M., Calvino F., Cano-Ott D., Capote R., Carrapiço C., Cennini P., Cerutti F., Chiaveri E., Chin M., Cortes G., Cortes-Giraldo M.A., Cosentino L., Couture A., Cox J., David S., Dillmann I., Domingo-Pardo C., Dressler R., Dridi W., Eleftheriadis C., Embid-Segura M., Ferrant L., Ferrari A., Finocchiaro P., Fraval K., Fujii K., Furman W., Ganesan S., Garcia A.R., Giubrone G., Gomez-Hornillos M.B., Goncalves I.F., Gonzalez-Romero E., Goverdovski A., Gramegna F., Griesmayer E., Guerrero C., Gurusamy P., Haight R., Heil M., Heinitz S., Igashira M., Isaev S., Jenkins D.G., Jericha E., Kadi Y., Kaeppeler F., Karadimos D., Karamanis D., Kerveno M., Ketlerov V., Kivel N., Kokkoris M., Konovalov V., Krticka M., Kroll J., Lampoudis C., Langer C., Lederer C., Leeb H., Lo Meo S., Losito R., Lozano M., Manousos A., Marganiec J., Martinez T., Marrone S., Massimi C., Mastinu P., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondelaers W., Moreau C., Mosconi M., Musumarra A., O’Brien S., Pancin J., Patronis N., Pavlik A., Pavlopoulos P., Perkowski J., Perrot L., Pigni M.T., Plag R., Plompen A., Plukis L., Poch A., Pretel C., Praena J., Quesada J., Rauscher T., Reifarth R., Riego A., Roman F., Rudolf G., Rubbia C., Rullhusen P., Salgado J., Santos C., Sarchiapone L., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Stephan C., Tagliente G., Tain J.L., Tavora L., Terlizzi R., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Villamarin D., Vincente M.C., Vlachoudis V., Vlastou R., Voss F., Wallner A., Walter S., Ware T., Weigand M., Weiß C., Wiesher M., Wisshak K., Wright T., and Zugec P.

Subjects
Physics, QC1-999
Abstract

The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN – n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

Published
2016
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14. Improved Nuclear Physics Near $A=61$ Refines Urca Neutrino Luminosities in Accreted Neutron Star Crusts

Author

Meisel, Zach, Hamaker, Alec, Bollen, G., Brown, B. A., Eibach, M., Gulyuz, K., Izzo, C., Langer, C., Montes, F., Ong, W. -J, Puentes, D., Redshaw, M., Ringle, R., Sandler, R., Schatz, H., Schwarz, S., Sumithrarachchi, C. S., Valverde, A. A., and Yandow, I. T.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We performed a Penning trap mass measurement of $^{61}{\rm Zn}$ at the National Superconducting Cyclotron Laboratory and NuShellX calculations of the $^{61}{\rm Zn}$ and $^{62}{\rm Ga}$ structure using the GXPF1A Hamiltonian to obtain improved estimates of the $^{61}{\rm Zn}(p,\gamma)^{62}{\rm Ga}$ and $^{60}{\rm Cu}(p,\gamma)^{61}{\rm Zn}$ reaction rates. Surveying astrophysical conditions for type-I X-ray bursts with the code MESA, implementing our improved reaction rates, and taking into account updated nuclear masses for $^{61}{\rm V}$ and $^{61}{\rm Cr}$ from the recent literature, we refine the neutrino luminosity from the important mass number $A=61$ urca cooling source in accreted neutron star crusts. This improves our understanding of the thermal barrier between deep heating in the crust and the shallow depths where extra heat is needed to explain X-ray superbursts, as well as the expected signature of crust urca neutrino emission in light curves of cooling transients., Comment: Submitted

Published
2021
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15. The Status and Future of Direct Nuclear Reaction Measurements for Stellar Burning

Author

Aliotta, M., Buompane, R., Couder, M., Couture, A., deBoer, R. J., Formicola, A., Gialanella, L., Glorius, J., Imbriani, G., Junker, M., Langer, C., Lennarz, A., Litvinov, Yu. A., Liu, W. -P., Lugaro, M., Matei, C., Meisel, Z., Piersanti, L., Reifarth, R., Robertson, D., Simon, A., Straniero, O., Tumino, A., Wiescher, M., and Xu, Y.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

The study of stellar burning began just over 100 years ago. Nonetheless, we do not yet have a detailed picture of the nucleosynthesis within stars and how nucleosynthesis impacts stellar structure and the remnants of stellar evolution. Achieving this understanding will require precise direct measurements of the nuclear reactions involved. This report summarizes the status of direct measurements for stellar burning, focusing on developments of the last couple of decades, and offering a prospectus of near-future developments., Comment: Accepted to Journal of Physics G as a Major Report. Corresponding author: Zach Meisel (meisel@ohio.edu)

Published
2021
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16. Coexisting normal and intruder configurations in $^{32}$Mg

Author

Kitamura, N., Wimmer, K., Poves, A., Shimizu, N., Tostevin, J. A., Bader, V. M., Bancroft, C., Barofsky, D., Baugher, T., Bazin, D., Berryman, J. S., Bildstein, V., Gade, A., Imai, N., Kröll, T., Langer, C., Lloyd, J., Lunderberg, E., Nowacki, F., Perdikakis, G., Recchia, F., Redpath, T., Saenz, S., Smalley, D., Stroberg, S. R., Utsuno, Y., Weisshaar, D., and Westerberg, A.

Subjects
Nuclear Experiment
Abstract

Situated in the so-called "island of inversion," the nucleus $^{32}$Mg is considered as an archetypal example of the disappearance of magicity at $N=20$. We report on high statistics in-beam spectroscopy of $^{32}$Mg with a unique approach, in that two direct reaction probes with different sensitivities to the underlying nuclear structure are employed at the same time. More specifically, states in $^{32}$Mg were populated by knockout reactions starting from $^{33}$Mg and $^{34}$Si, lying inside and outside the island of inversion, respectively. The momentum distributions of the reaction residues and the cross sections leading to the individual final states were confronted with eikonal-based reaction calculations, yielding a significantly updated level scheme for $^{32}$Mg and spin-parity assignments. By fully exploiting observables obtained in this measurement, a variety of structures coexisting in 32Mg was unraveled. Comparisons with theoretical predictions based on shell-model overlaps allowed for clear discrimination between different structural models, revealing that the complete theoretical description of this key nucleus is yet to be achieved.

Published
2021
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17. Experimental neutron capture data of 58Ni from the CERN n_TOF facility

Author

Žugec P., Barbagallo M., Colonna N., Bosnar D., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Duran I., Dzysiuk N., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gómez-Hornillos M.B., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Heinitz S., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Koehler P., Kokkoris M., Krtička M., Kroll J., Langer C., Lederer C., Leeb H., Leong L.S., Lo Meo S., Losito R., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P.F., Mastromarco M., Meaze M., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondalaers W., Paradela C., Pavlik A., Perkowski J., Pignatari M., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riegov A., Roman F., Rubbia C., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., and Wright T.

Subjects
Physics, QC1-999
Abstract

The neutron capture cross section of 58Ni was measured at the neutron time of flight facility n_TOF at CERN, from 27 meV to 400 keV neutron energy. Special care has been taken to identify all the possible sources of background, with the so-called neutron background obtained for the first time using high-precision GEANT4 simulations. The energy range up to 122 keV was treated as the resolved resonance region, where 51 resonances were identified and analyzed by a multilevel R-matrix code SAMMY. Above 122 keV the code SESH was used in analyzing the unresolved resonance region of the capture yield. Maxwellian averaged cross sections were calculated in the temperature range of kT = 5 – 100 keV, and their astrophysical implications were investigated.

Published
2015
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18. Determination of the $^{209}$Bi(n,$\gamma$)$^{210g}$Bi cross section using the NICE-Detector

Author

Al-Khasawneh, K., Borris, E., Brückner, B., Erbacher, P., Fiebiger, S., Göbel, K., Heftrich, T., Kisselbach, T., Kurtulgil, D., Langer, C., Reich, M., Reifarth, R., Thomas, B., Volknandt, M., and Weigand, M.

Subjects
Nuclear Experiment
Abstract

The capture cross section of $^{209}$Bi(n,$\gamma$)$^{210g}$Bi was measured at different astrophysically energies including thermal capture cross section (25 meV), resonance integral, and the Maxwellian averaged cross section at a thermal energy of $kT$ = 30 keV. The partial capture cross section ($\sigma_g$) was determined using the activation technique and by measuring the $^{210}$Po activity. The newly developed and tested NICE detector setup was used to measure the $\alpha$-activity of the $^{210}$Po. Using this setup the thermal and resonance integral cross sections were determined to be $16.2\;\pm\;0.97$~mb and $89.81\;\pm\;8.0$~mb, respectively. And the Maxwellian average cross section was measured to be $2.01\;\pm\;0.38$~mb., Comment: 26 pages, 8 figures

Published
2021
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19. Study of Ground State Wave-function of the Neutron-rich 29,30Na Isotopes through Coulomb Breakup

Author

Rahaman A., Datta Pramanik U., Aumann T., Beceiro S., Boretzky K., Caesar C., Carlson B.V., Catford W.N., Chakraborty S., Chatterjee S., Chartier M., Angelis G.De., Cortina-Gil D., Gonzalez-Diaz D., Emling H., Diaz Fernandez P., Fraile L.M., Ershova O., Geissel H., Heil M., Jonson B., Kelic A., Johansson H., Kruecken R., Kroll T., Kurcewicz J., Langer C., Bleis T.Le, Leifels Y., Munzenberg G., Marganiec J., Nociforo C., Najafi A., Panin V., Paschalis S., Pietri S., Plag R., Reifarth R., Ricciardi V., Rossi D., Ray J., Simon H., Scheidenberge C., Typel S., Taylor J., Togano Y., Volkov V., Weick H., Wagner A., Wamers F., Weigand M., Winfield J.S., Yakorev D., and Zoric M.

Subjects
Physics, QC1-999
Abstract

Coulomb breakup of unstable neutron rich nuclei 29,30Na around the ‘island of inversion’ has been studied at energy around 434 MeV/nucleon and 409 MeV/nucleon respectively. Four momentum vectors of fragments, decay neutron from excited projectile and γ-rays emitted from excited fragments after Coulomb breakup are measured in coincidence. For these nuclei, the low-lying dipole strength above one neutron threshold can be explained by direct breakup model. The analysis for Coulomb breakup of 29,30Na shows that large amount of the cross section yields the 28Na, 29Na core in ground state. The predominant ground-state configuration of 29,30Na is found to be 28Na(g.s)⊗νs1/2 and 29Na(g.s)⊗νs1/2,respectively.

Published
2014
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20. The nucleosynthesis of heavy elements in Stars: the key isotope 25Mg

Author

Massimi C., Koehler P., Kopecky S., Mingrone F., Schillebeeckx P., Vannini G., Altstadt S., Andrzejewski J., Audouin L., Barbagallo M., Bécares V., Bečvář F., Belloni F, Berthoumieux E., Billowes J., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Duran I., Dressler R., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Krtička M., Kroll J., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Mastinu P.F., Mastromarco M., Mendoza E., Mengoni A., Milazzo P.M., Mirea M., Mondalaers W., Paradela C., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Robles M.S., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

We have measured the radiative neutron-capture cross section and the total neutron-induced cross section of one of the most important isotopes for the s process, the 25Mg. The measurements have been carried out at the neutron time-of-flight facilities n_TOF at CERN (Switzerland) and GELINA installed at the EC-JRC-IRMM (Belgium). The cross sections as a function of neutron energy have been measured up to approximately 300 keV, covering the energy region of interest to the s process. The data analysis is ongoing and preliminary results show the potential relevance for the s process.

Published
2014
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21. 238U(n, γ) reaction cross section measurement with C6D6 detectors at the n_TOF CERN facility.

Author

Mingrone F., Massimi C., Vannini G., Altstadt S., Andrzejewski J., Audouin L., Barbagallo M., Bécares V., Bečvář F., Belloni F, Berthoumieux E., Billowes J., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Duran I., Dressler R., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Koehler P., Krtička M., Kroll J., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Losito R., Mallick A., Manousos A., Marganiec J., Martínez T., Mastinu P.F., Mastromarco M., Mendoza E., Mengoni A., Milazzo P.M., Mirea M., Mondalaers W., Paradela C., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Robles M.S., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The radiative capture cross section of 238U is very important for the developing of new reactor technologies and the safety of existing ones. Here the preliminary results of the 238U(n,γ) cross section measurement performed at n_TOF with C6D6 scintillation detectors are presented, paying particular attention to data reduction and background subtraction.

Published
2014
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22. Measurements of neutron cross sections for advanced nuclear energy systems at n_TOF (CERN)

Author

Barbagallo M., Colonna N., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Bečvář F., Belloni F, Berthoumieux E., Billowes J., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Duran I., Dressler R., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Koehler P., Krtička M., Kroll J., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Losito R., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P.F., Mastromarco M., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondalaers W., Paradela C., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The n_TOF facility operates at CERN with the aim of addressing the request of high accuracy nuclear data for advanced nuclear energy systems as well as for nuclear astrophysics. Thanks to the features of the neutron beam, important results have been obtained on neutron induced fission and capture cross sections of U, Pu and minor actinides. Recently the construction of another beam line has started; the new line will be complementary to the first one, allowing to further extend the experimental program foreseen for next measurement campaigns.

Published
2014
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23. Ground-state configuration of neutron-rich Aluminum isotopes through Coulomb Breakup

Author

Chakraborty S., Pramanik U. Datta, Aumann T., Beceiro S., Boretzky K., Caesar C., Carlson B.V., Catford W. N., Chatterjee S., Chartier M ., Cortina-Gil D., Angelis G.De., Gonzalez-Diaz D., Emling H., Fernandez P. Diaz, Fraile L. M., Ershova O., Geissel H., Heil M., Jonson B., Kelic A., Johansson H., Kruecken R., Kroll T., Kurcewicz J., Langer C., Bleis T. Le, Leifels Y., Munzenberg G., Marganiec J., Nociforo C., Najafi A., Panin V., Paschalis S., Pietri S., Plag R., Rahaman A., Reifarth R., Ricciardi V., Rossi D., Ray J., Simon H., Scheidenberger C., Typel S., Taylor J., Togano Y., Volkov V., Weick H., Wagner A., Wamers F., Weigand M., Winfield J. S., Yakorev D., and Zoric M.

Subjects
Physics, QC1-999
Abstract

Neutron-rich 34,35Al isotopes have been studied through Coulomb excitation using LAND-FRS setup at GSI, Darmstadt. The method of invariant mass analysis has been used to reconstruct the excitation energy of the nucleus prior to decay. Comparison of experimental CD cross-section with direct breakup model calculation with neutron in p3/2 orbital favours 34Al(g.s)⊗νp3/2 as ground state configuration of 35Al. But ground state configuration of 34Al is complicated as evident from γ-ray spectra of 33Al after Coulomb breakup of 34Al.

Published
2014
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24. Exclusive measurements of nuclear breakup reactions of 17Ne

Author

Wamers F., Marganiec J., Aksouh F., Aksyutina Yu., Álvarez-Pol H., Aumann T., Beceiro-Novo S., Bertulani C.A., Boretzky K., Borge M.J.G., Chartier M., Chatillon A., Chulkov L.V., Cortina-Gil D., Egorova I.A., Emling H., Ershova O., Forssén C., Fraile L.M., Fynbo H., Galaviz D., Geissel H., Grigorenko L.V., Heil M., Hoffmann D.H.H., Hoffmann J., Johansson H., Jonson B., Karagiannis C., Karakoç M., Kiselev O.A., Kratz J.V., Kulessa R., Kurz N., Langer C., Lantz M., Larsson K., Bleis T. Le, Lemmon R., Litvinov Yu.A., Mahata K., Müntz C., Nilsson T., Nociforo C., Nyman G., Ott W., Panin V., Parfenova Yu.L., Paschalis S., Perea A., Plag R., Reifarth R., Richter A., Rodriguez-Tajes C., Rossi D., Riisager K., Savran D., Schrieder G., Shul’gina N.B., Simon H., Stroth J., Sümmerer K., Taylor J., Tengblad O., Tengborn E., Weick H., Wimmer C., and Zhukov M.V.

Subjects
Physics, QC1-999
Abstract

We have studied one-proton-removal reactions of about 500MeV/u 17Ne beams on a carbon target at the R3B/LAND setup at GSI by detecting beam-like 15O-p and determining their relative-energy distribution. We exclusively selected the removal of a 17Ne halo proton, and the Glauber-model analysis of the 16F momentum distribution resulted in an s2 contribution in the 17Ne ground state of about 40%.

Published
2014
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25. Measurement of astrophysically important excitation energies of 58Zn with GRETINA

Author

Langer C., Montes F., Aprahamian A., Bardayan D. W., Bazin D., Brown B.A., Browne J., Crawford H., Cyburt R., Domingo-Pardo C., Gade A., George S., Hosmer P., Keek L., Kontos A., Lee I-Y., Lemasson A., Lunderberg E., Maeda Y., Matos M., Meisel Z., Noji S., Nystrom A., Perdikakis G., Pereira J., Quinn S., Recchia F., Schatz H., Scott M., Siegl K., Simon A., Smith M., Spyrou A., Stevens J., Stroberg R., Weisshaar D., Wheeler J., Wimmer K., and Zegers R.G.T.

Subjects
Physics, QC1-999
Abstract

The level structure of neutron-deficient 58Zn has been extracted experimentally. This nucleus is important for the rapid proton-capture process. 58Zn was produced by using a (d,n)-type transfer reaction on 57Cu in inverse kinematics at beam energies of 75 MeV/u. Several γ-ray transitions have been identified. The experiment utilized the state-of-the-art GRETINA γ-ray energy tracking array in conjunction with the largeacceptance spectrometer S800 at NSCL. The excitation energies of the identified low-lying states in 58Zn are important for constraining the 57Cu(p,γ)58Zn reaction rate under X-ray burst conditions.

Published
2014
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26. Neutron cross-sections for advanced nuclear systems: the n_TOF project at CERN

Author

Barbagallo M., Mastromarco M., Colonna N., Altstadt S., Andrzejewski J., Audouin L., Bécares V., Bečvář F., Belloni F, Berthoumieux E., Billowes J., Bosnar D., Brugger M., Calviani M., Calviño F., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Duran I., Dressler R., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gonçalves I.F., González-Romero E., Griesmayer E., Guerrero C., Gunsing F., Hernández-Prieto A., Jenkins D.G., Jericha E., Kadi Y., Käppeler F., Karadimos D., Kivel N., Koehler P., Krtička M., Kroll J., Lampoudis C., Langer C., Leal-Cidoncha E., Lederer C., Leeb H., Leong L.S., Losito R., Manousos A., Marganiec J., Martínez T., Massimi C., Mastinu P.F., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Mondalaers W., Paradela C., Pavlik A., Perkowski J., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego A., Rubbia C., Sabaté-Gilarte M., Sarmento R., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Tagliente G., Tain J.L., Tarrío D., Tassan-Got L., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vermeulen M.J., Vlachoudis V., Vlastou R., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n_TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.

Published
2014
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27. Unveiling the Two-Proton Halo Character of 17Ne: Exclusive Measurement of Quasi-free Proton-Knockout Reactions

Author

Lehr, C., Wamers, F., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernandez, P. Diaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Heine, M., Hoffmann, D. H. H., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Bleis, T. Le, Lemmon, R., Litvinov, Yu. A., Loeher, B., Mahata, K., Marganiec-Galazka, J., Muentz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Suemmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Subjects
Nuclear Experiment
Abstract

The proton drip-line nucleus 17Ne is investigated experimentally in order to determine its two-proton halo character. A fully exclusive measurement of the 17Ne(p,2p)16F->15O+p quasi-free one-proton knockout reaction has been performed at GSI at around 500 MeV/nucleon beam energy. All particles resulting from the scattering process have been detected. The relevant reconstructed quantities are the angles of the two protons scattered in quasi-elastic kinematics, the decay of 16F into 15O (including gamma decays from excited states) and a proton, as well as the 15O+p relative-energy spectrum and the 16F momentum distributions. The latter two quantities allow an independent and consistent determination of the ratio of l=0 and l=2 motion of the valence protons in 17Ne. With a resulting relatively small l=0 component of only around 35(3)%, it is concluded that 17Ne exhibits a rather modest halo character only. The quantitative agreement of the two values deduced from the energy spectrum and the momentum distributions supports the theoretical treatment of the calculation of momentum distributions after quasi-free knockout reactions at high energies by taking into account distortions based on the Glauber theory. Moreover, the experimental data allow the separation of valence-proton knockout and knockout from the 15O core. The latter process contributes with 11.8(3.1) mb around 40% to the total proton-knockout cross section of 30.3(2.3) mb, which explains previously reported contradicting conclusions derived from inclusive cross sections., Comment: 7 pages, 5 figures

Published
2021
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28. $\beta$-decay of $^{61}$V and its Role in Cooling Accreted Neutron Star Crusts

Author

Ong, W. -J., Brown, E. F., Browne, J., Ahn, S., Childers, K., Crider, B. P., Dombos, A. C., Gupta, S. S., Hitt, G. W., Langer, C., Lewis, R., Liddick, S. N., Lyons, S., Meisel, Z., Möller, P., Montes, F., Naqvi, F., Pereira, J., Prokop, C., Richman, D., Schatz, H., Schmidt, K., and Spyrou, A.

Subjects
Nuclear Experiment
Abstract

The interpretation of observations of cooling neutron star crusts in quasi-persistent X-ray transients is affected by predictions of the strength of neutrino cooling via crust Urca processes. The strength of crust Urca neutrino cooling depends sensitively on the electron-capture and $\beta$-decay ground-state to ground-state transition strengths of neutron-rich rare isotopes. Nuclei with mass number $A=61$ are predicted to be among the most abundant in accreted crusts, and the last remaining experimentally undetermined ground-state to ground-state transition strength was the $\beta$-decay of $^{61}$V. This work reports the first experimental determination of this transition strength, a ground-state branching of 8.1$^{+2.2}_{-2.0} \%$, corresponding to a log $ft$ value of 5.5$^{+0.2}_{-0.2}$. This result was achieved through the measurement of the $\beta$-delayed $\gamma$ rays using the total absorption spectrometer SuN and the measurement of the $\beta$-delayed neutron branch using the neutron long counter system NERO at the National Superconducting Cyclotron Laboratory at Michigan State University. This method helps to mitigate the impact of the Pandemonium effect in extremely neutron-rich nuclei on experimental results. The result implies that $A=61$ nuclei do not provide the strongest cooling in accreted neutron star crusts as expected by some predictions, but that their cooling is still larger compared to most other mass numbers. Only nuclei with mass numbers 31, 33, and 55 are predicted to be cooling more strongly. However, the theoretical predictions for the transition strengths of these nuclei are not consistently accurate enough to draw conclusions on crust cooling. With the experimental approach developed in this work all relevant transitions are within reach to be studied in the future., Comment: 6 pages, 3 figures Copyright by APS Link to publication: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.262701

Published
2021
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29. Angular distribution in the neutron-induced fission of actinides

Author

Leong L.S., Tassan-Got L., Tarrio D., Audouin L., Paradela C., Duran I., Le Naour C., Altstadt S., Andrzejewsky J., Barbagallo M., Bécares V., Bečvář F., Belloni F., Berthoumieux E., Billowes J., Boccone V., Bosnar D., Brugger M., Calvino F., Calviani M., Cano-Ott D., Carrapiço C., Cerutti F., Chiaveri E., Chin M., Colonna N., Cortés G., Cortés-Giraldo M.A., Diakaki M., Domingo-Pardo C., Dressler R., Dzysiuk N., Eleftheriadis C., Ferrari A., Fraval K., Ganesan S., García A.R., Giubrone G., Gómez-Hornillos M.B., Gonçalves I.F., González-Romero, Griesmayer E., Guerrero C., Gunsing F., Gurusamy P., Jenkins D.G., Jericha E., Kadi E., Käppeler F., Karadimos D., Kivel N., Koehler P., Kokkoris M., Korschinek G., Kroll J., Krtička M., Langer C., Lederer C., Leeb H., Losito R., Manousos A., Marganiec J., Massimi C., Martínez T., Mastinu P.F., Mastromarco M., Meaze M., Mengon A., Mendoza E., Milazzo P.M., Mingrone T., Mirea M., Mondelaers W., Pavlik A., Perkowski J., Pignatari M., Plompen A., Praena J., Quesada J.M., Rauscher T., Reifhart R., Riego A., Roman F., Rubbia C., Sarmento R., Schillebeeckx P., Schmidt S., Schumann D., Taín J.L., Tagliente G., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Versaci R., Vermeulen M.J., Vlachoudis V., Vlastou V., Wallner A., Ware T., Weigand M., Weiß C., Wright T., and Zǔgec

Subjects
Physics, QC1-999
Abstract

Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD) has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC), for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n_TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered.

Published
2013
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30. Determination of luminosity for in-ring reactions: A new approach for the low-energy domain

Author

Xing, Y. M., Glorius, J., Varga, L., Bott, L., Bruckner, C. Brandau B., Chen, R. J., Chen, X., Dababneh, S., Davinson, T., Erbacher, P., Fiebiger, S., Gassner, T., Gobel, K., Groothuis, M., Gumberidze, A., Gyurky, G., Heil, M., Hess, R., Hensch, R., Hillmann, P., Hillenbrand, P. -M., Hinrichs, O., Jurado, B., Kausch, T., Khodaparast, A., Kisselbach, T., Klapper, N., Kozhuharov, C., Kurtulgil, D., Lane, G., Langer, C., Lederer-Woods, C., Lestinsky, M., Litvinov, S., Litvinov, Yu. A., Loher, B., Petridis, N., Popp, U., Reed, M., Reifarth, R., Sanjari, M. S., Simon, H., Slavkovska, Z., Spillmann, U., Steck, M., Stohlker, T., Stumm, J., Szucs, T., Nguyen, T. T., Zadeh, A. Taremi, Thomas, B., Torilov, S. Yu., Tornqvist, H., Trageser, C., Trotsenko, S., Volknandt, M., Wang, M., Weigand, M., Wolf, C., Woods, P. J., Zhang, Y. H., and Zhou, X. H.

Subjects
Nuclear Experiment
Abstract

Luminosity is a measure of the colliding frequency between beam and target and it is a crucial parameter for the measurement of absolute values, such as reaction cross sections. In this paper, we make use of experimental data from the ESR storage ring to demonstrate that the luminosity can be precisely determined by modelling the measured Rutherford scattering distribution. The obtained results are in good agreement with an independent measurement based on the x-ray normalization method. Our new method provides an alternative way to precisely measure the luminosity in low-energy stored-beam configurations. This can be of great value in particular in dedicated low-energy storage rings where established methods are difficult or impossible to apply., Comment: 8 pages, 5 figures

Published
2020
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31. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author

Syndikus, I., Petri, M., Macchiavelli, A. O., Paschalis, S., Bertulani, C. A., Aumann, T., Alvarez-Pol, H., Atar, L., Beceiro-Novo, S., Benlliure, J., Boillos, J. M., Boretzky, K., Borge, M. J. G., Brown, B. A., Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chulkov, L. V., Cortina-Gil, D., Cravo, E., Crespo, R., Dillmann, I., Fernández, P. Díaz, Elekes, Z., Enders, J., Farinon, F., Fraile, L. M., Redondo, D. Galaviz, Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Kröll, T., Kurz, N., Langer, C., Bleis, T. Le, Machado, J. F. D. C., Marganiec-Gałazka, J., Nacher, E., Nilsson, T., Nociforo, C., Panin, V., Perea, A., Pietri, S. B., Plag, R., Reifarth, R., Revel, A., Ribeiro, G., Rigollet, C., Rossi, D. M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Tengblad, O., Togano, Y., Vandebrouck, M., Volkov, V., Wheldon, F. Wamers C., Wilson, G. L., Winfield, J. S., Weick, H., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z = 6 spin-orbit shell gap towards the neutron dripline. To do so, we employed $^{A}$N(p,2p)$^{A-1}$C quasi-free scattering reactions to measure the proton component of the 2$^+_1$ state of $^{16,18,20}$C. The experimental findings support the notion of a moderate reduction of the proton 1p$_{1/2}$-1p$_{3/2}$ spin-orbit splitting, at variance to recent claims for a prevalent Z = 6 magic number towards the neutron dripline., Comment: 27 pages, 5 figures, 2 tables. Submitted to Physics Letter B

Published
2020
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32. Electron capture of Xe$^{54+}$ in collisions with H${_2}$ molecules in the energy range between 5.5 MeV/u and 30.9 MeV/u

Author

Kröger, F. M., Weber, G., Herdrich, M. O., Glorius, J., Langer, C., Slavkovská, Z., Bott, L., Brandau, C., Brückner, B., Blaum, K., Chen, X., Dababneh, S., Davinson, T., Erbacher, P., Fiebiger, S., Gaßner, T., Göbel, K., Groothuis, M., Gumberidze, A., Gyürky, Gy., Hagmann, S., Hahn, C., Heil, M., Hess, R., Hensch, R., Hillmann, P., Hillenbrand, P. -M., Hinrichs, O., Jurado, B., Kausch, T., Khodaparast, A., Kisselbach, T., Klapper, N., Kozhuharov, C., Kurtulgil, D., Lane, G., Lederer-Woods, C., Lestinsky, M., Litvinov, S., Litvinov, Yu. A., Löher, B., Nolden, F., Petridis, N., Popp, U., Reed, M., Reifarth, R., Sanjari, M. S., Simon, H., Spillmann, U., Steck, M., Stumm, J., Szücs, T., Nguyen, T. T., Zadeh, A. Taremi, Thomas, B., Torilov, S. Yu., Törnqvist, H., Trageser, C., Trotsenko, S., Volknandt, M., Weigand, M., Wolf, C., Woods, P. J., Shevelko, V. P., Tolstikhina, I. Yu., and Stöhlker, Th.

Subjects
Physics - Atomic Physics
Abstract

The electron capture process was studied for Xe$^{54+}$ colliding with H$_2$ molecules at the internal gas target of the ESR storage ring at GSI, Darmstadt. Cross section values for electron capture into excited projectile states were deduced from the observed emission cross section of Lyman radiation, being emitted by the hydrogen-like ions subsequent to the capture of a target electron. The ion beam energy range was varied between 5.5 MeV/u and 30.9 MeV/u by applying the deceleration mode of the ESR. Thus, electron capture data was recorded at the intermediate and in particular the low collision energy regime, well below the beam energy necessary to produce bare xenon ions. The obtained data is found to be in reasonable qualitative agreement with theoretical approaches, while a commonly applied empirical formula significantly overestimates the experimental findings.

Published
2020
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33. Nuclear Mass Measurements Map the Structure of Atomic Nuclei and Accreting Neutron Stars

Author

Meisel, Z., George, S., Ahn, S., Bazin, D., Brown, B. A., Browne, J., Carpino, J. F., Chung, H., Cyburt, R. H., Estradé, A., Famiano, M., Gade, A., Langer, C., Matoš, M., Mittig, W., Montes, F., Morrissey, D. J., Pereira, J., Schatz, H., Schatz, J., Scott, M., Shapira, D., Smith, K., Stevens, J., Tan, W., Tarasov, O., Towers, S., Wimmer, K., Winkelbauer, J. R., Yurkon, J., and Zegers, R. G. T.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We present mass excesses (ME) of neutron-rich isotopes of Ar through Fe, obtained via TOF-$B\rho$ mass spectrometry at the National Superconducting Cyclotron Laboratory. Our new results have significantly reduced systematic uncertainties relative to a prior analysis, enabling the first determination of ME for $^{58,59}{\rm Ti}$, $^{62}{\rm V}$, $^{65}{\rm Cr}$, $^{67,68}{\rm Mn}$, and $^{69,70}{\rm Fe}$. Our results show the $N=34$ subshell weaken at Sc and vanish at Ti, along with the absence of an $N=40$ subshell at Mn. This leads to a cooler accreted neutron star crust, highlighting the connection between the structure of nuclei and neutron stars., Comment: Accepted for publication as a Rapid Communication in Physical Review C

Published
2020
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34. A high fidelity light-shift gate for clock-state qubits

Author

Baldwin, C. H., Bjork, B. J., Foss-Feig, M., Gaebler, J. P., Hayes, D., Kokish, M. G., Langer, C., Sedlacek, J. A., Stack, D., and Vittorini, G.

Subjects
Quantum Physics, Physics - Atomic Physics
Abstract

To date, the highest fidelity quantum logic gates between two qubits have been achieved with variations on the geometric-phase gate in trapped ions, with the two leading variants being the Molmer-Sorensen gate and the light-shift (LS) gate. Both of these approaches have their respective advantages and challenges. For example, the latter is technically simpler and is natively insensitive to optical phases, but it has not been made to work directly on a clock-state qubit. We present a new technique for implementing the LS gate that combines the best features of these two approaches: By using a small ($\sim {\rm MHz}$) detuning from a narrow (dipole-forbidden) optical transition, we are able to operate an LS gate directly on hyperfine clock states, achieving gate fidelities of $99.74(4)\%$ using modest laser power at visible wavelengths. Current gate infidelities appear to be dominated by technical noise, and theoretical modeling suggests a path towards gate fidelity above $99.99\%$., Comment: 4+ pages, 3 figures, and supplemental material

Published
2020
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35. Constraining the Neutron Star Compactness: Extraction of the $^{23}$Al($p,\gamma$) Reaction Rate for the $rp$-Process

Author

Wolf, C., Langer, C., Montes, F., Pereira, J., Ong, W. -J., Poxon-Pearson, T., Ahn, S., Ayoub, S., Baumann, T., Bazin, D., Bender, P. C., Brown, B. A., Browne, J., Crawford, H., Cyburt, R. H., Deleeuw, E., Elman, B., Fiebiger, S., Gade, A., Gastis, P., Lipschutz, S., Longfellow, B., Meisel, Z., Nunes, F. M., Perdikakis, G., Reifarth, R., Richter, W. A., Schatz, H., Schmidt, K., Schmitt, J., Sullivan, C., Titus, R., Weisshaar, D., Woods, P. J., Zamora, J. C., and Zegers, R. G. T.

Subjects
Nuclear Experiment, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics, Nuclear Theory
Abstract

The $^{23}$Al($p,\gamma$)$^{24}$Si reaction is among the most important reactions driving the energy generation in Type-I X-ray bursts. However, the present reaction-rate uncertainty limits constraints on neutron star properties that can be achieved with burst model-observation comparisons. Here, we present a novel technique for constraining this important reaction by combining the GRETINA array with the neutron detector LENDA coupled to the S800 spectrograph at the National Superconducting Cyclotron Laboratory. The $^{23}$Al($d,n$) reaction was used to populate the astrophysically important states in $^{24}$Si. This enables a measurement in complete kinematics for extracting all relevant inputs necessary to calculate the reaction rate. For the first time, a predicted close-lying doublet of a 2$_2^+$ and (4$_1^+$,0$_2^+$) state in $^{24}$Si was disentangled, finally resolving conflicting results from two previous measurements. Moreover, it was possible to extract spectroscopic factors using GRETINA and LENDA simultaneously. This new technique may be used to constrain other important reaction rates for various astrophysical scenarios.

Published
2019
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36. Approaching the Gamow window with stored ions: Direct measurement of $^{124}$Xe(p,$\gamma$) in the ESR storage ring

Author

Glorius, J., Langer, C., Slavkovská, Z., Bott, L., Brandau, C., Brückner, B., Blaum, K., Chen, X., Dababneh, S., Davinson, T., Erbacher, P., Fiebiger, S., Gaßner, T., Göbel, K., Groothuis, M., Gumberidze, A., Gyürky, G., Heil, M., Hess, R., Hensch, R., Hillmann, P., Hillenbrand, P. -M., Hinrichs, O., Jurado, B., Kausch, T., Khodaparast, A., Kisselbach, T., Klapper, N., Kozhuharov, C., Kurtulgil, D., Lane, G., Lederer-Woods, C., Lestinsky, M., Litvinov, S., Litvinov, Yu. A., Löher, B., Nolden, F., Petridis, N., Popp, U., Rauscher, T., Reed, M., Reifarth, R., Sanjari, M. S., Savran, D., Simon, H., Spillmann, U., Steck, M., Stöhlker, T., Stumm, J., Surzhykov, A., Szücs, T., Nguyen, T. T., Zadeh, A. Taremi, Thomas, B., Torilov, S. Yu., Törnqvist, H., Träger, M., Trageser, C., Trotsenko, S., Varga, L., Volknandt, M., Weick, H., Weigand, M., Wolf, C., Woods, P. J., and Xing, Y. M.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of low-energy proton-capture cross sections of $^{124}$Xe in a heavy ion storage ring. $^{124}$Xe$^{54+}$ ions of five different beam energies between 5.5 AMeV and 8 AMeV were stored to collide with a windowless hydrogen target. The $^{125}$Cs reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and X-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron- and ${\gamma}$-widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.

Published
2019
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37. Diverse mechanisms in proton knockout reactions from the Borromean nucleus 17Ne

Author

Wamers, F., Lehr, C., Marganiec-Gałązka, J., Aksouh, F., Aksyutina, Yu., Alvarez-Pol, H., Atar, L., Aumann, T., Beceiro-Novo, S., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Caesar, C., Chartier, M., Chatillon, A., Chulkov, L. V., Cortina-Gil, D., Fernández, P. Díaz, Emling, H., Ershova, O., Fraile, L. M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Heil, M., Holl, M., Johansson, H. T., Jonson, B., Karagiannis, C., Kiselev, O. A., Kratz, J. V., Kulessa, R., Kurz, N., Langer, C., Lantz, M., Le Bleis, T., Lemmon, R., Litvinov, Yu. A., Mahata, K., Müntz, C., Nilsson, T., Nociforo, C., Ott, W., Panin, V., Paschalis, S., Perea, A., Plag, R., Reifarth, R., Richter, A., Riisager, K., Rodriguez-Tajes, C., Rossi, D., Savran, D., Scheit, H., Schrieder, G., Schrock, P., Simon, H., Stroth, J., Sümmerer, K., Tengblad, O., Weick, H., and Wimmer, C.

Published
2023
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38. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author

Syndikus, I, Petri, M, Macchiavelli, AO, Paschalis, S, Bertulani, CA, Aumann, T, Alvarez-Pol, H, Atar, L, Beceiro-Novo, S, Benlliure, J, Boillos, JM, Boretzky, K, Borge, MJG, Brown, BA, Caamaño, M, Caesar, C, Casarejos, E, Catford, W, Cederkall, J, Chakraborty, S, Chulkov, LV, Cortina-Gil, D, Cravo, E, Crespo, R, Datta Pramanik, U, Dillmann, I, Díaz Fernández, P, Elekes, Z, Enders, J, Farinon, F, Fraile, LM, Galaviz, D, Geissel, H, Gernhäuser, R, Golubev, P, Göbel, K, Heil, M, Heine, M, Heinz, A, Henriques, A, Holl, M, Johansson, HT, Jonson, B, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Kröll, T, Kurz, N, Langer, C, Le Bleis, T, Machado, J, Marganiec-Gałązka, J, Nacher, E, Nilsson, T, Nociforo, C, Panin, V, Perea, A, Pietri, SB, Plag, R, Rahaman, A, Reifarth, R, Revel, A, Ribeiro, G, Rigollet, C, Rossi, DM, Savran, D, Scheit, H, Simon, H, Sorlin, O, Tengblad, O, Togano, Y, Vandebrouck, M, Volkov, V, Wamers, F, Wheldon, C, Wilson, GL, Winfield, JS, Weick, H, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, and Zuber, K

Subjects
Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z=6 spin-orbit shell gap towards the neutron dripline. To do so, we employed NA(p,2p)CA−1 quasi-free scattering reactions to measure the proton component of the 21+ state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1p1/2−1p3/2 spin-orbit splitting, at variance to recent claims for a prevalent Z=6 magic number towards the neutron dripline.

Published
2020

39. Measurement of Nuclear Interaction Cross Sections towards Neutron-Skin Thickness Determination

Author

Ponnath, L., primary, Aumann, T., additional, Bertulani, C.A., additional, Gernhäuser, R., additional, Heil, M., additional, Almusidi, T., additional, Alvarez-Pol, H., additional, Atar, L., additional, Atkins, L., additional, Ayyad, Y., additional, Benlliure, J., additional, Boretzky, K., additional, Borge, M.J.G., additional, Bott, L.T., additional, Bruni, G., additional, Brückner, B., additional, Cabanelas, P., additional, Caesar, C., additional, Casarejos, E., additional, Cederkall, J., additional, Corsi, A., additional, Cortina-Gil, D., additional, Dueñas, J.A., additional, Duer, M., additional, Elekes, Z., additional, Escribano Rodriguez, S., additional, Fabbietti, L., additional, Falduto, A., additional, Feijoo, M., additional, Feijoo Fontan, M., additional, Fonseca, L.M., additional, Frotscher, A., additional, Galaviz, D., additional, Galiana, E., additional, García-Jiménez, G., additional, Gašparic̀, I., additional, Geraci, E.I., additional, Gillibert, A., additional, Gnoffo, B., additional, González Caamaño, D., additional, Graña González, A., additional, Göbel, K., additional, Hartig, A.-L., additional, Heinz, A., additional, Hensel, T., additional, Holl, M., additional, Horvat, A., additional, Jedele, A., additional, Jelavic̀ Malenica, D., additional, Jenegger, T., additional, Johansson, H.T., additional, Jonson, B., additional, Kalantar-Nayestanaki, N., additional, Kelic-Heil, A., additional, Kiselev, O.A., additional, Klenze, P., additional, Kresan, D., additional, Kröll, T., additional, Kudaibergenova, E., additional, Kurtulgil, D., additional, Körper, D., additional, Labiche, M., additional, Langer, C., additional, Lihtar, I., additional, Litvinov, Yu.A., additional, Löher, B., additional, Mayer, J., additional, Murillo Morales, S., additional, Nacher, E., additional, Nilsson, T., additional, Obertelli, A., additional, Panin, V., additional, Park, J., additional, Paschalis, S., additional, Perea, A., additional, Petri, M., additional, Pirrone, S., additional, Pohl, T., additional, Reifarth, R., additional, Rhee, H.-B., additional, Rodriguez-Sanchez, J.L., additional, Rose, L., additional, Rossi, D.M., additional, Russotto, P., additional, Savran, D., additional, Scheit, H., additional, Simon, H., additional, Storck-Dutine, S., additional, Stott, A.M., additional, Sürder, C., additional, Taniuchi, R., additional, Tengblad, O., additional, Teubig, P., additional, Trache, L., additional, Trimarchi, M., additional, Törnqvist, H.T., additional, Varga, L., additional, Wagner, V., additional, and Wamers, F., additional

Published
2024
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40. Weakly Bound Neutron-Rich Nuclei and Cosmic Phenomena

Author

Datta, Ushasi, Rahaman, A., Chakraborty, S., Agrawal, B. K., Aumann, T., Boretzky, K., Caesar, C., Emling, H., Geissel, H., Langer, C., Bleis, T. Le, Leifels, Y., Marganiec, J., Münzenberg, G., Nociforo, C., Plag, R., Reinferth, R., Ricciardi, V., Rossi, D., Scheidenberger, C., Simon, H., Typel, S., Volkov, V., Wamers, F., Winfield, J. S., Weick, H., Jonson, B., Johansson, H., Nilsson, T., Wagner, A., Angelis, G. De., Carlson, B. V., Kröll, T., Scheit, H., Krücken, R., Catford, W. N., Novo, S. Beceiro, Cortina, D., Fernandez, P. Diaz, Taylor, J., and Chartier, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The single particle and bulk properties of the neutron-rich nuclei constrain fundamental issues in nuclear physics and nuclear astrophysics like the limits of existence of quantum many body systems (atomic nuclei), the equation of state of neutron-rich matter, neutron star, nucleosynthesis, evolution of stars, neutron star merging etc.. The state of the art of Coulomb breakup of the neutron-rich nuclei has been used to explore those properties. Unambiguous information on detailed components of the ground-state wave-function along with quantum numbers of the valence neutron of the nuclei have been obtained from the measurement of threshold strength along with the $\gamma$-rays spectra of the core following Coulomb breakup. The shape of this threshold strength is a finger-print of the quantum numbers of the nucleon. We investigated the ground-state properties of the neutron-rich Na, Mg, Al nuclei around N $\sim$ 20 using this method at GSI, Darmstadt. Very clear evidence has been observed for melting and merging of long cherished magic shell gaps at N = 20, 28. The evanescent neutron-rich nuclei imprint their existence in stellar explosive scenarios (r-process etc.). Coulomb dissociation (CD) is one of the important indirect measurements of the capture cross-section which may provide valuable input to the model for star evolution process, particularly the r-process. Some valuable bulk properties of the neutron-rich nuclei like the density dependent symmetry energy,neutron skin etc. play a key role in understanding cosmic phenomena and these properties have been studied via electromagnetic excitation. Preliminary results of electromagnetic excitation of the neutron-rich nucleus, $^{32}$Mg are presented., Comment: Talk presented CIPANP2018. 9 pages, LaTeX, 10 eps figures

Published
2018

41. Strong neutron pairing in core+4n nuclei

Author

Revel, A., Marques, F. M., Sorlin, O., Aumann, T., Caesar, C., Holl, M., Panin, V., Vandebrouck, M., Wamers, F., Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Casarejos, E., Catford, W. N., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Pramanik, U. Datta, Fernandez, P. Diaz, Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhauser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kroll, T., Kurz, N., Labiche, M., Langer, C., Bleis, T. Le, Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Movsesyan, A., Nacher, E., Najafi, M., Nikolskii, E., Nilsson, T., Nociforo, C., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Roder, M., Rossi, D., Savran, D., Scheit, H., Simon, H., Syndikus, I., Taylor, J. T., Tengblad, O., Thies, R., Togano, Y., Velho, P., Volkov, V., Wagner, A., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

The emission of neutron pairs from the neutron-rich $N\!=\!12$ isotones $^{18}$C and $^{20}$O has been studied by high-energy nucleon knockout from $^{19}$N and $^{21}$O secondary beams, populating unbound states of the two isotones up to 15~MeV above their two-neutron emission thresholds. The analysis of triple fragment-$n$-$n$ correlations shows that the decay $^{19}$N$(-1p)^{18}$C$^*\!\rightarrow^{16}$C+$n$+$n$ is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a $^{14}$C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay $^{21}$O$(-1n)^{20}$O$^*\!\rightarrow^{18}$O+$n$+$n$, attributed to its formation through the knockout of a deeply-bound neutron that breaks the $^{16}$O core and reduces the number of pairs., Comment: 6 pages, 4 figures, accepted for publication in Phys. Rev. Lett

Published
2018
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42. Lifetime measurement of the 21+ state in 74Rb and isospin properties of quadrupole transition strengths at N = Z

Author

Morse, C, Iwasaki, H, Lemasson, A, Dewald, A, Braunroth, T, Bader, VM, Baugher, T, Bazin, D, Berryman, JS, Campbell, CM, Gade, A, Langer, C, Lee, IY, Loelius, C, Lunderberg, E, Recchia, F, Smalley, D, Stroberg, SR, Wadsworth, R, Walz, C, Weisshaar, D, Westerberg, A, Whitmore, K, and Wimmer, K

Subjects
Lifetimes, Nuclear transition probabilities, Isospin, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

Self-conjugate nuclei in the A≈70–80 region have attracted a great deal of attention due to phenomena such as shape coexistence and increasing collectivity along the N=Z line. We investigate the structure of nuclei in this region through lifetime measurements using the GRETINA array. The first implementation of the Differential Recoil Distance Doppler Shift technique with fast radioactive beams is demonstrated and verified through a measurement of the well-known B(E2;21+→01+) transition strength in 74Kr. The method is then applied to determine the B(E2;21+→01+) transition strength in 74Rb, the heaviest odd–odd N=Z nucleus for which this quantity has been determined. This result and extended systematics along N=Z suggest the dominance of the isoscalar part of the quadrupole transition strengths in self-conjugate nuclei, as well as the possible presence of shape coexistence in 74Rb.

Published
2018

43. Lifetime measurement of the 2 1 + state in 74Rb and isospin properties of quadrupole transition strengths at N = Z

Author

Morse, C, Iwasaki, H, Lemasson, A, Dewald, A, Braunroth, T, Bader, VM, Baugher, T, Bazin, D, Berryman, JS, Campbell, CM, Gade, A, Langer, C, Lee, IY, Loelius, C, Lunderberg, E, Recchia, F, Smalley, D, Stroberg, SR, Wadsworth, R, Walz, C, Weisshaar, D, Westerberg, A, Whitmore, K, and Wimmer, K

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Lifetimes, Nuclear transition probabilities, Isospin, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract

Self-conjugate nuclei in the A≈70–80 region have attracted a great deal of attention due to phenomena such as shape coexistence and increasing collectivity along the N=Z line. We investigate the structure of nuclei in this region through lifetime measurements using the GRETINA array. The first implementation of the Differential Recoil Distance Doppler Shift technique with fast radioactive beams is demonstrated and verified through a measurement of the well-known B(E2;21+→01+) transition strength in 74Kr. The method is then applied to determine the B(E2;21+→01+) transition strength in 74Rb, the heaviest odd–odd N=Z nucleus for which this quantity has been determined. This result and extended systematics along N=Z suggest the dominance of the isoscalar part of the quadrupole transition strengths in self-conjugate nuclei, as well as the possible presence of shape coexistence in 74Rb.

Published
2018

45. A new Time-of-flight detector for the R3B setup

Author

Heil, M., Kelić-Heil, A., Bott, L., Almusidi, T., Alvarez-Pol, H., Atar, L., Atkins, L., Aumann, T., Benlliure, J., Boretzky, K., Brückner, B., Cabanelas, P., Caesar, C., Casarejos, E., Cederkall, J., Chulkov, L., Corsi, A., Dueñas, J., Erbacher, P., Rodriguez, S. Escribano, Falduto, A., Feijoo, M., Frotscher, A., Frühauf, J., Gašparić, I., Borge, M. J. G., Gerbig, J., Gernhäuser, R., Gilbert, M., Glorius, J., Gnoffo, B., Göbel, K., Caamaño, D. Gonzalez, Grein, A., Hartig, A.-L., Heggen, H., Heine, M., Heinz, A., Holl, M., Homm, I., Horvat, A., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kamenyero, A., Khodaparast, A., Kiselev, O., Klenze, P., Knösel, M., Koch, K., Körper, D., Kröll, T., Kurtulgil, D., Kurz, N., Löher, B., Langer, C., Lehr, C., Litvinov, Y., Liu, H., Morales, S. Murillo, Nácher, E., Nilsson, T., Park, J., Paschalis, S., Pellegri, L., Perea, A., Petri, M., Pohl, T., Ponnath, L., Popočovski, R., Reifarth, R., Rhee, H.-B., Sanchez, J. L. Rodriguez, Rossi, D., Sürder, C., Sánchez-Benítez, A. M., Savran, D., Scheit, H., Simon, H., Slavkovská, Z., Storck-Dutine, S., Sun, Y., Törnqvist, H. T., Tanaka, J., Tengblad, O., Thomas, B., Varga, L., Volknandt, M., Wagner, V., Wamers, F., and Zanetti, L.

Published
2022
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46. Effective proton-neutron interaction near the drip line from unbound states in $^{25,26}$F

Author

Vandebrouck, M., Lepailleur, A., Sorlin, O., Aumann, T., Caesar, C., Holl, M., Panin, V., Wamers, F., Stroberg, S. R., Holt, J. D., Santos, F. De Oliveira, Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Bogner, S. K., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Pramanik, U. Datta, Fernandez, P. Diaz, Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhauser, R., Gibelin, J., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Hergert, H., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Bleis, T. Le, Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Marques, F. M., Movsesyan, A., Nacher, E., Najafi, M., Nikolskii, E., Nilsson, T., Nociforo, C., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Röder, M., Rossi, D., Savran, D., Scheit, H., Schwenk, A., Simon, H., Syndikus, I., Taylor, J., Tengblad, O., Thies, R., Togano, Y., Velho, P., Volkov, V., Wagner, A., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The $^{26}$F nucleus, composed of a deeply bound $\pi0d\_{5/2}$ proton and an unbound $\nu0d\_{3/2}$ neutron on top of an $^{24}$O core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The $J^{\pi} = 1^{+}\_1, 2^{+}\_1,4^{+}\_1$ bound states have been determined, and only a clear identification of the $J^{\pi} =3^{+}\_1$ is missing.Purpose: We wish to complete the study of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet in $^{26}$F, by studying the energy and width of the $J^{\pi} =3^{+}\_1$ unbound state. The method was firstly validated by the study of unbound states in $^{25}$F, for which resonances were already observed in a previous experiment.Method: Radioactive beams of $^{26}$Ne and $^{27}$Ne, produced at about $440A$\,MeV by the FRagment Separator at the GSI facility, were used to populate unbound states in $^{25}$F and $^{26}$F via one-proton knockout reactions on a CH$\_2$ target, located at the object focal point of the R$^3$B/LAND setup. The detection of emitted $\gamma$-rays and neutrons, added to the reconstruction of the momentum vector of the $A-1$ nuclei, allowed the determination of the energy of three unbound states in $^{25}$F and two in $^{26}$F. Results: Based on its width and decay properties, the first unbound state in $^{25}$F is proposed to be a $J^{\pi} = 1/2^-$ arising from a $p\_{1/2}$ proton-hole state. In $^{26}$F, the first resonance at 323(33)~keV is proposed to be the $J^{\pi} =3^{+}\_1$ member of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet. Energies of observed states in $^{25,26}$F have been compared to calculations using the independent-particle shell model, a phenomenological shell-model, and the ab initio valence-space in-medium similarity renormalization group method.Conclusions: The deduced effective proton-neutron interaction is weakened by about 30-40\% in comparison to the models, pointing to the need of implementing the role of the continuum in theoretical descriptions, or to a wrong determination of the atomic mass of $^{26}$F., Comment: 14 pages, 7 figures, 3 tables, submitted to PRC

Published
2017
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47. Low-lying level structure of $^{56}$Cu and its implications on the rp process

Author

Ong, W-J., Langer, C., Montes, F., Aprahamian, A., Bardayan, D. W., Bazin, D., Brown, B. A., Browne, J., Crawford, H., Cyburt, R., Deleeuw, E. B., Domingo-Pardo, C., Gade, A., George, S., Hosmer, P., Keek, L., Kontos, A., Lee, I-Y., Lemasson, A., Lunderberg, E., Maeda, Y., Matos, M., Meisel, Z., Noji, S., Nunes, F. M., Nystrom, A., Perdikakis, G., Pereira, J., Quinn, S. J., Recchia, F., Schatz, H., Scott, M., Siegl, K., Simon, A., Smith, M., Spyrou, A., Stevens, J., Stroberg, S. R., Weisshaar, D., Wheeler, J., Wimmer, K., and Zegers, R. G. T.

Subjects
Nuclear Experiment, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The low-lying energy levels of proton-rich $^{56}$Cu have been extracted using in-beam $\gamma$-ray spectroscopy with the state-of-the-art $\gamma$-ray tracking array GRETINA in conjunction with the S800 spectrograph at the National Superconducting Cyclotron Laboratory at Michigan State University. Excited states in $^{56}$Cu serve as resonances in the $^{55}$Ni(p,$\gamma$)$^{56}$Cu reaction, which is a part of the rp-process in type I x-ray bursts. To resolve existing ambiguities in the reaction Q-value, a more localized IMME mass fit is used resulting in $Q=639\pm82$~keV. We derive the first experimentally-constrained thermonuclear reaction rate for $^{55}$Ni(p,$\gamma$)$^{56}$Cu. We find that, with this new rate, the rp-process may bypass the $^{56}$Ni waiting point via the $^{55}$Ni(p,$\gamma$) reaction for typical x-ray burst conditions with a branching of up to $\sim$40$\%$. We also identify additional nuclear physics uncertainties that need to be addressed before drawing final conclusions about the rp-process reaction flow in the $^{56}$Ni region., Comment: 8 pages, accepted for Phys. Rev. C

Published
2017
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48. Interdisziplinäres Management einer Larynxstenose im Säuglingsalter: von der Einsatzstelle über den Operationssaal bis zur Intensivstation.

Author

Schneck, E., Käbisch, S., Sander, M., Thul, J., Schramm, C., Hahn, C. C., Zajonz, T., Sommer, B., Arens, C., and Langer, C.

Subjects
LARYNGEAL diseases, EMERGENCY medical services, RESUSCITATION, INTENSIVE care units, HEALTH care teams, OPERATING rooms, CRITICAL care medicine, CHILDREN
Abstract

Copyright of Anaesthesiologie & Intensivmedizin is the property of DGAI e.V. - Deutsche Gesellschaft fur Anasthesiologie und Intensivmedizin e.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2024
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49. Neutron capture cross section measurement of 238U at the n TOF CERN facility with C6D6 scintillation detectors in the energy region from 1 eV to 700 keV

Author

Collaboration, n_TOF, Mingrone, F., Massimi, C., Vannini, G., Colonna, N., Gunsing, F., Žugec, P., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Duran, I., Dressler, R., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Hernández-Prieto, A., Jenkins, D. G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Krtička, 1 M., Kroll, J., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L. S., Meo, S. Lo, Losito, R., Mallick, A., Manousos, A., Marganiec, J., Martínez, T., Mastinu, P. F., Mastromarco, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mirea, M., Mondalaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, A., Robles, M. S., Rubbia, C., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Variale, V., Vaz, P., Ventura, A., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear Experiment
Abstract

The aim of this work is to provide a precise and accurate measurement of the 238U(n,g) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these 238U(n,g) measurements performed at the n_TOF CERN facility are presented in this work. The gamma-ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher., Comment: 15 pages, 10 captioned figures

Published
2016
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50. Future Perspectives for Surrogate-Reaction Studies at Storage Rings

Author

Henriques, A., Jurado, B., Denis-Petit, D., Chiron, T., Gaudefroy, L., Glorius, J., Grieser, M., Langer, C., Litvinov, Y. A., Mathieu, L., Méot, V., Pérez-Sánchez, R., Pibernat, J., Reifarth, R., Roig, O., Thomas, B., Thomas, B. A., Thomas, J. C., Tsekhanovich, I., Escher, Jutta, editor, Alhassid, Yoram, editor, Bernstein, Lee A., editor, Brown, David, editor, Fröhlich, Carla, editor, Talou, Patrick, editor, and Younes, Walid, editor

Published
2021
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