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1,783 results on '"Weigand M"'

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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5. Measurement of the 242Pu(n, γ) cross section from thermal to 500 keV at the Budapest research reactor and CERN n_TOF-EAR1 facilities

Author

Lerendegui-Marco J, Guerrero C., Mendoza E., Quesada J. M., Eberhardt K., Junghans A., Krtiička M., Belgya T., Maróti B., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea J., Barbagallo M., Barros S., Bečvář F., Beinrucker C., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Caamaño M., Calviño F., Calviani M., Cano-Ott D, Cardella R., Casanovas A., Castelluccio D. M., Cerutti F., Chen Y. H., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M. A., Cosentino L., Damone L. A., Diakaki M., Domingo-Pardo C, Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Göbel K., García A. R., Gawlik A., Glodariu T., Gonçalves I. F., González-Romero E., Goverdovski A., Griesmayer E., Gunsing F., Harada H., Heftrich T., Heinitz S., Heyse J., Jenkins D. G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Knapova I., Kokkoris M., Leal-Cidoncha E, Lederer C., Leeb H., Lo Meo S., Lonsdale S. J., Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mengoni A., Milazzo P. M., Mingrone F., Mirea M., Montesano S., Musumarra A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Porras J. I., Praena J., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A, Rout P. C., Rubbia C., Ryan J. A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A. G., 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., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Warren S., Weigand M., Weiss C., Wolf C., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The design and operation of innovative nuclear systems requires a better knowledge of the capture and fission cross sections of the Pu isotopes. For the case of capture on 242Pu, a reduction of the uncertainty in the fast region down to 8-12% is required. Moreover, aiming at improving the evaluation of the fast energy range in terms of average parameters, the OECD NEA High Priority Request List (HPRL) requests high-resolution capture measurements with improved accuracy below 2 keV. The current uncertainties also affect the thermal point, where previous experiments deviate from each other by 20%. A fruitful collaboration betwen JGU Mainz and HZ Dresden-Rossendorf within the EC CHANDA project resulted in a 242Pu sample consisting of a stack of seven fission-like targets making a total of 95(4) mg of 242Pu electrodeposited on thin (11.5 μm) aluminum backings. This contribution presents the results of a set of measurements of the 242Pu(n, γ) cross section from thermal to 500 keV combining different neutron beams and techniques. The thermal point was determined at the Budapest Research Reactor by means of Neutron Activation Analysis and Prompt Gamma Analysis, and the resolved (1 eV - 4 keV) and unresolved (1 - 500 keV) resonance regions were measured using a set of four Total Energy detectors at the CERN n_TOF-EAR1.

Published
2020
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6. 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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8. $^{179}$Ta(n,$\gamma$) cross-section measurement and the astrophysical origin of $^{180}$Ta isotope

Author

Garg, R., Dellmann, S., Lederer-Woods, C., Bruno, C. G., Eberhardt, K., Geppert, C., Heftrich, T., Kajan, I., Käppeler, F., Phoenix, B., Reifarth, R., Schumann, D., Weigand, M., and Wheldon, C.

Subjects
Nuclear Experiment
Abstract

Tantalum-180m is nature's rarest (quasi) stable isotope and its astrophysical origin is an open question. A possible production site of this isotope is the slow neutron capture process in Asymptotic Giant Branch stars, where it can be produced via neutron capture reactions on unstable $^{179}$Ta. We report a new measurement of the $^{179}$Ta($n,\gamma$)$^{180}$Ta cross section at thermal neutron energies via the activation technique. Our results for the thermal and resonance-integral cross-sections are 952 $\pm$ 57 b and 2013 $\pm$ 148 b, respectively. The thermal cross section is in good agreement with the only previous measurement (Phys. Rev C {\bf 60} 025802, 1999), while the resonance integral is different by a factor of $\approx$1.7. While neutron energies in this work are smaller than the energies in a stellar environment, our results may lead to improvements in theoretical predictions of the stellar cross section.

Published
2023
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9. Mode purity and structural analysis of x-ray vortices generated by spiral zone plates

Author

Baluktsian, M., Loetgering, L., Dogan, G., Sanli, U., Weigand, M., Rose, M., Bykova, I., Schuetz, G., and Keskinbora, K.

Subjects
Physics - Optics, Physics - Accelerator Physics
Abstract

In the visible spectrum vortex beams have found various applications, ranging from optical tweezers to super-resolution imaging. Recently, these beams have been demonstrated using X-rays and electron beams. However, so far, no in-depth discussion has been carried out on the vortex quality, which could become essential for a variety of vortex applications. Here, we investigate the mode conversion efficiency (MCE), vortex structure and stability (in terms of vortex splitting) of the vortex fields generated by spiral zone plates (SZP). We have designed and fabricated SZPs with varying topological charge of both binary and kinoform profile. Kinoforms are known for their 100 % diffraction efficiency in the ideal case. In this work, both types are contrasted with regard to the vortex quality. Utilizing ptychographic coherent diffraction imaging and by comparing to simulations the wavefront of the generated fields is characterized. It was found, that the MCE and vortex structure exhibit the same dependencies on material and ZP properties as the diffraction efficiency (DE) and that the kinoform profile in this sense also improves the vortex quality. With growing SZP charge the MCE decreases. The results link the parameters of optics to the properties of the vortices and help to maximize the performance of ZP based vortex generators for future applications.

Published
2022

11. 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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12. The measurement programme at the neutron time-of-flight facility n_TOF at CERN

Author

Gunsing F., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea-Correa J., Barbagallo M., Barros S., Bečvář F., Beinrucker C., Belloni F., Berthoumieux E., Billowes J., Bosnar D., Brown A., Brugger M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Castelluccio D.M., Cerutti F., Chen Y.H., Chiaveri E., Colonna N., Cortés-Giraldo M.A., Cortés G., Cosentino L., Damone L.A., Deo K., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Frost R.J.W., Furman V., Ganesan S., García A.R., Gawlik A., Gheorghe I., Gilardoni S., Glodariu T., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Göbel K., Harada H., Heftrich T., Heinitz S., Hernández-Prieto A., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Kalamara A., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Krtička M., Kurtulgil D., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui J., Licata M., Meo S. Lo, Lonsdale S.J., Losito R., Macina D., Marganiec J., Martínez T., 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., Montesano S., Musumarra A., Nolte R., Negret A., Oprea A., Palomo-Pinto F.R., Paradela C., Patronis N., Pavlik A., Perkowski J., Porras I., Praena J., Quesada J.M., Radeck D., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Rout P., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A.G., Sosnin N.V., Stamatopoulos A., Suryanarayana S.V., 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., Vlachoudis V., Vlastou R., Wallner A., Warren S., Weigand M., Weiss C., Wolf C., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Neutron-induced reaction cross sections are important for a wide variety of research fields ranging from the study of nuclear level densities, nucleosynthesis to applications of nuclear technology like design, and criticality and safety assessment of existing and future nuclear reactors, radiation dosimetry, medical applications, nuclear waste transmutation, accelerator-driven systems and fuel cycle investigations. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN’s neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n_TOF will be presented.

Published
2017
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13. 7Be(n,α) and 7Be(n,p) cross-section measurement for the cosmological lithium problem at the n_TOF facility at CERN

Author

Barbagallo M., Colonna N., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea J., Barros S., Bečvář F., Beinrucker C., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Castelluccio D.M., Cerutti F., Chen Y.H., Chiaveri E., Cortés G., Cortés-Giraldo M.A., Cosentino L., Damone L.A., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Göbel K., García A.R., Gawlik A., Glodariu T., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Harada H., Heftrich T., Heinitz S., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Krtička M., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui-Marco J., Meo S. Lo, Lonsdale S.J., Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E.A., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Montesano S., Musumarra A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Porras J.I., Praena J., Quesada J.M., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A., Rout P.C., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A.G., 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., Weigand M., Weiss C., Wolf C., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The Cosmological Lithium Problem refers to the large discrepancy between the abundance of primordial 7Li predicted by the standard theory of Big Bang Nucleosynthesis and the value inferred from the so-called “Spite plateau” in halo stars. A possible explanation for this longstanding puzzle in Nuclear Astrophysics is related to the incorrect estimation of the destruction rate of 7Be, which is responsible for the production of 95% of primordial Lithium. While charged-particle induced reactions have mostly been ruled out, data on the 7Be(n,α) and 7Be(n,p) reactions are scarce or completely missing, so that a large uncertainty still affects the abundance of 7Li predicted by the standard theory of Big Bang Nucleosynthesis. Both reactions have been measured at the n_TOF facility at CERN, providing for the first time data in a wide neutron energy range.

Published
2017
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14. The 33S(n,α)30Si cross section measurement at n_TOF-EAR2 (CERN): From 0.01 eV to the resonance region

Author

Sabaté-Gilarte M., Praena J., Porras I., Quesada J.M., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea-Correa J., Barbagallo M., Barros S., Bečvář F., Beinrucker C., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Camaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Castelluccio D.M., Cerutti F., Chen Y.H., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M.A., Cosentino L., Damone L.A., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Gödel K., García-Rios A., Gawlik A., Glodariu T., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Harada H., Heftrich T., Heinitz S., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Krtička M., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui-Marco J., Meo S. Lo, Lonsdale S.J., Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E.A., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Montesano S., Musumarra A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A., Rout P., Rubbia C., Ryan J.A., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A.G., 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., Weigand M., Weiss C., Wolf C., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The 33S(n,α)30Si cross section measurement, using 10B(n,α) as reference, at the n_TOF Experimental Area 2 (EAR2) facility at CERN is presented. Data from 0.01 eV to 100 keV are provided and, for the first time, the cross section is measured in the range from 0.01 eV to 10 keV. These data may be used for a future evaluation of the cross section because present evaluations exhibit large discrepancies. The 33S(n,α)30Si reaction is of interest in medical physics because of its possible use as a cooperative target to boron in Neutron Capture Therapy (NCT).

Published
2017
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15. Measurement of the 240Pu(n,f) cross-section at the CERN n_TOF facility: First results from experimental area II (EAR-2)

Author

Stamatopoulos A., Tsinganis A., Colonna N., Vlastou R., Kokkoris M., Schillebeeckx P., Plompen A., Heyse J., Žugec P., Barbagallo M., Calviani M., Berthoumieux E., Chiaveri E., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea J., Barros S., Bečvář F., Beinrucker C., Belloni F., Billowes J., Boccone V., Bosnar D., Brugger M., Caamaño M., Calviño F., Cano-Ott D., Cerutti F., Cortés G., Cortés-Giraldo M.A., Cosentino L., Damone L.A., Deo K., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Frost R.J.W., Furman V., Göbel K., Gómez-Hornillos M.B., García A.R., Gheorghe I., Glodariu T., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Harada H., Heftrich T., Heinitz S., Hernández-Prieto A., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Krtička M., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui-Marco J., Licata M., Meo S. Lo, Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Montesano S., Musumarra A., Nolte R., Palomo-Pinto F.R., Paradela C., Patronis N., Pavlik A., Perkowski J., Porras J.I., Praena J., Quesada J.M., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Saxena A., Schmidt S., Schumann D., Sedyshev P., Smith A.G., Suryanarayana S.V., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tassan-Got L., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Wallner A., Warren S., Weigand M., Weiss C., and Wright T.

Subjects
Physics, QC1-999
Abstract

The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n_TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n_TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented.

Published
2017
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16. Characterization of the n_TOF EAR-2 neutron beam

Author

Chen Y.H., Tassan-Got L., Audouin L., Le Naour C., Durán I., Casarejos E., Aberle O., Andrzejewski J., Bécares V., Bacak M., Balibrea J., Barbagallo M., Barros S., Bečvář F., Beinrucker C., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Castelluccio D.M., Cerutti F., Chiaveri E., Colonna N., Cortés G., Cortés-Giraldo M.A., Cosentino L., Damone L.A., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Göbel K., Gómez-Hornillos M.B., García A.R., Gawlik A., Glodariu T., Gonçalves I.F., González E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Harada H., Heftrich T., Heinitz S., Heyse J., Jenkins D.G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Krtička M., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui-Marco J., Meo S. Lo, Lonsdale S.J., Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E.A., Mendoza E., Mengoni A., Milazzo P.M., Mingrone F., Mirea M., Montesano S., Musumarra A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Porras J.I., Praena J., Quesada J.M., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A., Robles M., Rout P.C., Rubbia C., Ryan J.A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A.G., Stamatopoulos A., Tagliente G., Tain J.L., Tarifeño-Saldivia A., Tsinganis A., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vlachoudis V., Vlastou R., Wallner A., Warren S., Weigand M., Weiss C., Wolf C., Woods P.J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n_TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam pro↓le and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash.

Published
2017
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17. 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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18. 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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19. 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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20. 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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21. 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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22. Deterministic Generation and Guided Motion of Magnetic Skyrmions by Focused He$^+$-Ion Irradiation

Author

Kern, L. -M., Pfau, B., Deinhart, V., Schneider, M., Klose, C., Gerlinger, K., Wittrock, S., Engel, D., Will, I., Günther, C. M., Liefferink, R., Mentink, J. H., Wintz, S., Weigand, M., Huang, M. -J., Battistelli, R., Metternich, D., Büttner, F., Höflich, K., and Eisebitt, S.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Magnetic skyrmions are quasiparticles with non-trivial topology, envisioned to play a key role in next-generation data technology while simultaneously attracting fundamental research interest due to their emerging topological charge. In chiral magnetic multilayers, current-generated spin-orbit torques or ultrafast laser excitation can be used to nucleate isolated skyrmions on a picosecond timescale. Both methods, however, produce randomly arranged skyrmions, which inherently limits the precision on the location at which the skyrmions are nucleated. Here, we show that nanopatterning of the anisotropy landscape with a He$^+$-ion beam creates well-defined skyrmion nucleation sites, thereby transforming the skyrmion localization into a deterministic process. This approach allows to realize control of individual skyrmion nucleation as well as guided skyrmion motion with nanometer-scale precision, which is pivotal for both future fundamental studies of skyrmion dynamics and applications.

Published
2022
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24. 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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25. The CERN n_TOF facility: a unique tool for nuclear data measurement

Author

Mingrone F., Aberle O., Andrzejewski J., Audouin L., Bécares V., Bacak M., Balibrea-Correa J., Barbagallo M., Barros S., Bečvář F., Beinrucker C., Berthoumieux E., Billowes J., Bosnar D., Brugger M., Caamaño M., Calviño F., Calviani M., Cano-Ott D., Cardella R., Casanovas A., Castelluccio D. M., Cerutti F., Chen Y., Chiaveri E., Colonna N., Cortés-Giraldo M. A., Cortés G., Cosentino L., Damone L., Diakaki M., Domingo-Pardo C., Dressler R., Dupont E., Durán I., Fernández-Domínguez B., Ferrari A., Ferreira P., Finocchiaro P., Furman V., Ganesan S., Garcia-Rios A. A., Gawlik A., Gheorghe I., Glodariu T., Gonçalves I. F., Gonzàlez E., Goverdovski A., Griesmayer E., Guerrero C., Gunsing F., Göbel K., Harada H., Heftrich T., Heinitz S., Heyse J., Jenkins G., Jericha E., Käppeler F., Kadi Y., Katabuchi T., Kavrigin P., Ketlerov V., Khryachkov V., Kimura A., Kivel N., Kokkoris M., Krtička M., Leal-Cidoncha E., Lederer C., Leeb H., Lerendegui J., Lo Meo S., Lonsdale S., Losito R., Macina D., Marganiec J., Martínez T., Massimi C., Mastinu P., Mastromarco M., Matteucci F., Maugeri E. A., Mendoza E., Mengoni A., Milazzo P. M., Mirea M., Montesano S., Musumarra A., Nolte R., Oprea A., Patronis N., Pavlik A., Perkowski J., Praena J., Quesada J. M., Rajeev K., Rauscher T., Reifarth R., Riego-Perez A., Rout P., Rubbia C., Ryan J. A., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schmidt S., Schumann D., Sedyshev P., Smith A. G., 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., Weigand M., Weiss C., Wolf C., Woods P. J., Wright T., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The study of the resonant structures in neutron-nucleus cross-sections, and therefore of the compound-nucleus reaction mechanism, requires spectroscopic measurements to determine with high accuracy the energy of the neutron interacting with the material under study. To this purpose, the neutron time-of-flight facility n_TOF has been operating since 2001 at CERN. Its characteristics, such as the high intensity instantaneous neutron flux, the wide energy range from thermal to few GeV, and the very good energy resolution, are perfectly suited to perform high-quality measurements of neutron-induced reaction cross sections. The precise and accurate knowledge of these cross sections plays a fundamental role in nuclear technologies, nuclear astrophysics and nuclear physics. Two different measuring stations are available at the n_TOF facility, called EAR1 and EAR2, with different characteristics of intensity of the neutron flux and energy resolution. These experimental areas, combined with advanced detection systems lead to a great flexibility in performing challenging measurement of high precision and accuracy, and allow the investigation isotopes with very low cross sections, or available only in small quantities, or with very high specific activity. The characteristics and performances of the two experimental areas of the n_TOF facility will be presented, together with the most important measurements performed to date and their physics case. In addition, the significant upcoming measurements will be introduced.

Published
2016
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26. 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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27. 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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28. 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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29. 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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30. 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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31. 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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32. 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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33. 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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34. 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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35. 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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36. Thoracic Emergencies

Author

Hecker, A., Noll, J., Weigand, M. A., Hirschburger, Markus, Riedel, Jens G., Reichert, M., Padberg, W., Hecker, M., Coccolini, Federico, Series Editor, Coimbra, Raul, Series Editor, Kirkpatrick, Andrew W., Series Editor, Di Saverio, Salomone, Series Editor, Ansaloni, Luca, Editorial Board Member, Balogh, Zsolt, Editorial Board Member, Biffl, Walt, Editorial Board Member, Catena, Fausto, Editorial Board Member, Davis, Kimberly, Editorial Board Member, Ferrada, Paula, Editorial Board Member, Fraga, Gustavo, Editorial Board Member, Ivatury, Rao, Editorial Board Member, Kluger, Yoram, Editorial Board Member, Leppaniemi, Ari, Editorial Board Member, Maier, Ron, Editorial Board Member, Moore, Ernest E., Editorial Board Member, Napolitano, Lena, Editorial Board Member, Peitzman, Andrew, Editorial Board Member, Reilly, Patrick, Editorial Board Member, Rizoli, Sandro, Editorial Board Member, Sakakushev, Boris E., Editorial Board Member, Sartelli, Massimo, Editorial Board Member, Scalea, Thomas, Editorial Board Member, Spain, David, Editorial Board Member, Stahel, Philip, Editorial Board Member, Sugrue, Michael, Editorial Board Member, Velmahos, George, Editorial Board Member, Weber, Dieter, Editorial Board Member, Tarasconi, Antonio, editor, Bui, Simona, editor, Chirica, Mircea, editor, Roth, Gaël, editor, and Nahmias, Jeffry, editor

Published
2023
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38. 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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39. Observation of compact ferrimagnetic skyrmions in DyCo$_3$ film

Author

Chen, K., Lott, D., Philippi-Kobs, A., Weigand, M., Luo, C., and Radu, F.

Subjects
Condensed Matter - Materials Science
Abstract

Owing to the experimental discovery of magnetic skyrmions stabilized by the Dzyaloshinskii-Moriya and/or dipolar interactions in thin films, there is a recent upsurge of interest in magnetic skyrmions with antiferromagnetic spins in order to overcome the fundamental limitations inherent with skyrmions in ferromagnetic materials. Here, we report on the observation of compact ferrimagnetic skyrmions for the class of amorphous alloys consisting of 4f rare-earth and 3d transition-metal elements with perpendicular magnetic anisotropy, using a DyCo$_3$ film, that are identified by combining x-ray magnetic scattering, scanning transmission x-ray microscopy, and Hall transport technique. These skyrmions, with antiparallel aligned Dy and Co magnetic moments and a characteristic core radius of about 40~nm, are formed during the nucleation and annihilation of the magnetic maze-like domain pattern exhibiting a topological Hall effect contribution. Our findings provide a promising route for fundamental research in the field of ferrimagnetic/antiferromagnetic spintronics towards practical applications., Comment: 7 pages, 4 figures

Published
2020

40. 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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44. X-Ray Imaging of Mixed States of Skyrmions and Helices in FeGe

Author

Wilson, M. N., Turnbull, L. A., Gross, F., Birch, M. T., Verezhak, J. A. T., Twitchett-Harrison, A. C., Trager, N., Weigand, M., Schutz, G., Grafe, J., and Hatton, P. D.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report scanning transmission X-ray microscopy of mixed helical and skyrmion magnetic states in thin FeGe lamellae. This imaging of the out-of-plane magnetism allows clear identification of the different magnetic states, and reveals details about the coexistence of helical and skyrmion states. In particular, our data show that finite length helices are continuously deformable down to the size of individual skyrmions and are hence topologically equivalent to skyrmions. Furthermore, we observe transition states between helical and skyrmion states across the thickness of the lamella that are evidence for frozen Bloch points in the sample after field cooling., Comment: Further analysis by the authors suggests that the evidence we presented for the zipping transition between skyrmions and helices was flawed. This mistaken interpretation resulted from slight misalignment between positive and negative circularly polarized images used to produce the XMCD STXM images

Published
2019

45. Real-space imaging of confined magnetic skyrmion tubes

Author

Birch, M. T., Cortés-Ortuño, D., Turnbull, L. A., Wilson, M. N., Groß, F., Träger, N., Laurenson, A., Bukin, N., Moody, S. H., Weigand, M., Schütz, G., Popescu, H., Fan, R., Steadman, P., Verezhak, J. A. T., Balakrishnan, G., Loudon, J. C., Twitchett-Harrison, A. C., Hovorka, O., Fangohr, H., Ogrin, F., Gräfe, J., and Hatton, P. D.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Magnetic skyrmions are topologically nontrivial particles with a potential application as information elements in future spintronic device architectures. While they are commonly portrayed as two dimensional objects, in reality magnetic skyrmions are thought to exist as elongated, tube-like objects extending through the thickness of the sample. Study of this skyrmion tube (SkT) state is highly relevant for investigating skyrmion metastability and for implementation in recently proposed magnonic computing. However, direct experimental imaging of skyrmion tubes has yet to be reported. Here, we demonstrate the first real-space observation of skyrmion tubes in a lamella of FeGe using resonant magnetic x-ray imaging and comparative micromagnetic simulations, confirming their extended structure. The formation of these structures at the edge of the sample highlights the importance of confinement and edge effects in the stabilisation of the SkT state, opening the door to further investigations into this unexplored dimension of the skyrmion spin texture.

Published
2019
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46. Extracting the Dynamic Magnetic Contrast in Time-Resolved X-ray Transmission Microscopy

Author

Schaffers, T., Feggeler, T., Pile, S., Meckenstock, R., Buchner, M., Spoddig, D., Ney, V., Farle, M., Wende, H., Wintz, S., Weigand, M., Ohldag, H., Ollefs, K., and Ney, A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Using a time-resolved detection scheme in scanning transmission X-ray microscopy (STXM) we measured element resolved ferromagnetic resonance (FMR) at microwave frequencies up to 10\,GHz and a spatial resolution down to 20\,nm at two different synchrotrons. We present different methods to separate the contribution of the background from the dynamic magnetic contrast based on the X-ray magnetic circular dichroism (XMCD) effect. The relative phase between the GHz microwave excitation and the X-ray pulses generated by the synchrotron, as well as the opening angle of the precession at FMR can be quantified. A detailed analysis for homogeneous and inhomogeneous magnetic excitations demonstrates that the dynamic contrast indeed behaves as the usual XMCD effect. The dynamic magnetic contrast in time-resolved STXM has the potential be a powerful tool to study the linear and non-linear magnetic excitations in magnetic micro- and nano-structures with unique spatial-temporal resolution in combination with element selectivity., Comment: 9 pages, 7 figures

Published
2019
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47. Nanoscale X-Ray Imaging of Spin Dynamics in Yttrium Iron Garnet

Author

Förster, J., Wintz, S., Bailey, J., Finizio, S., Josten, E., Meertens, D., Dubs, C., Bozhko, D. A., Stoll, H., Dieterle, G., Träger, N., Raabe, J., Slavin, A. N., Weigand, M., Gräfe, J., and Schütz, G.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Time-resolved scanning transmission x-ray microscopy (TR-STXM) has been used for the direct imaging of spin wave dynamics in thin film yttrium iron garnet (YIG) with spatial resolution in the sub 100 nm range. Application of this x-ray transmission technique to single crystalline garnet films was achieved by extracting a lamella (13x5x0.185 $\mathrm{\mu m^3}$) of liquid phase epitaxy grown YIG thin film out of a gadolinium gallium garnet substrate. Spin waves in the sample were measured along the Damon-Eshbach and backward volume directions of propagation at gigahertz frequencies and with wavelengths in a range between 100~nm and 10~$\mathrm{\mu}$m. The results were compared to theoretical models. Here, the widely used approximate dispersion equation for dipole-exchange spin waves proved to be insufficient for describing the observed Damon-Eshbach type modes. For achieving an accurate description, we made use of the full analytical theory taking mode-hybridization effects into account.

Published
2019
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48. 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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