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1. Measurement of the 235U(n,f) cross section relative to the 10B(n,α) reaction with Micromegas detectors at the CERN n_TOF facility: First results

Author

Michalopoulou Veatriki, Diakaki Maria, Vlastou Rosa, Kokkoris Michael, Stamatopoulos Athanasios, Tsinganis Andrea, Eleme Zinovia, Patronis Nikolas, Heyse Jan, Schillebeeckx Peter, Tassan-Got Laurent, Barbagallo Massimo, Colonna Nicola, Urlass Sebastian, Macina Daniela, Chiaveri Enrico, Aberle Oliver, Alcayne Victor, Amaducci Simone, Andrzejewski Józef, Audouin Laurent, Babiano-Suarez Victor, Bacak Michael, Bennett Samuel, Berthoumieux Eric, Billowes Jon, Bosnar Damir, Brown Adam, Busso Maurizio, Caamaño Manuel, Caballero-Ontanaya Luis, Calviño Francisco, Calviani Marco, Cano-Ott Daniel, Casanovas Adria, Cerutti Francesco, Cortés Guillem, Cortés-Giraldo Miguel, Cosentino Luigi, Cristallo Sergio, Damone Lucia-Anna, Davies Paul-John, Dietz Mirco, Domingo-Pardo César, Dressler Rugard, Ducasse Quentin, Dupont Emmeric, Durán Ignacio, Fernández-Domínguez Beatriz, Ferrari Alfredo, Finocchiaro Paolo, Göbel Kathrin, Garg Ruchi, Gawlik-Ramięga Aleksandra, Gilardoni Simone, Gonçalves Isabel, González-Romero Enrique, Guerrero Carlos, Gunsing Frank, Harada Hideo, Heinitz Stephan, Jenkins David, Junghans Arnd, Käppeler† Franz, Kadi Yacine, Kimura Atsushi, Knapová Ingrid, Krtička Milan, Kurtulgil Deniz, Ladarescu Ion, Lederer-Woods Claudia, Leeb Helmut, Lerendegui-Marco Jorge, Lonsdale Sarah-Jane, Manna Alice, Martínez Trinitario, Masi Alessandro, Massimi Cristian, Mastinu Pierfrancesco, Mastromarco Mario, Maugeri Emilio-Andrea, Mazzone Annamaria, Mendoza Emilio, Mengoni Alberto, Milazzo Paolo, Mingrone Federica, Moreno-Soto Javier, Musumarra Agatino, Negret Alexandru, Nolte Ralf, Ogállar Francisco, Oprea Andreea, Pavlik Andreas, Perkowski Jarosław, Piersanti Luciano, Petrone Cristina, Pirovano Elisa, Porras Ignacio, Praena Javier, Quesada José-Manuel, Ramos-Doval Diego, Rauscher Thomas, Reifarth René, Rochman Dimitri, Rubbia Carlo, Sabaté-Gilarte Marta, Saxena Alok, Schumann Dorothea, Sekhar Adhitya, Smith Gavin, Sosnin Nikolay, Sprung Peter, Tagliente Giuseppe, Tain José, Tarifeño-Saldivia Ariel, Thomas Benedikt, Torres-Sánchez Pablo, Ulrich Jiri, Valenta Stanislav, Vannini Gianni, Variale Vincenzo, Vaz Pedro, Ventura Alberto, Vescovi Diego, Vlachoudis Vasilis, Wallner Anton, Woods Philip-John, Wright Tobias, and Žugec Petar

Subjects
Physics, QC1-999
Abstract

Neutron cross section measurements are often made relative to a neutron cross section standard. Thus, the accuracy of the neutron standards determines the best possible accuracy of the neutron measurements. The 235U(n,f) cross section is widely used as reference, while it is considered a standard at thermal point and between 0.15 to 200 MeV. For this reason, additional cross section data for the 235U(n,f) reaction are useful in order to improve the accuracy and to extend the energy range of the standard. In this work, preliminary results of the measurement of the 235U(n,f) cross-section relative to the standard 10B(n,a) reaction are presented. The high accuracy measurement was performed at the experimental area EAR-1 of the n_TOF facility at CERN, aiming at covering the energy range from the thermal region up to approximately 100 keV. The samples were produced at JRC-Geel in Belgium, while the experimental setup was based on Micromegas detectors.

Published
2023
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2. Investigation of the 7Li(p,n) neutron fields at high energies

Author

Brückner Benjamin, Erbacher Philipp, Göbel Kathrin, Heftrich Tanja, Khasawneh Kafa, Kurtulgil Deniz, Langer Christoph, Nolte Ralf, Reich Markus, Reifarth René, Thomas Benedikt, Weigand Mario, Wiescher Michael, and Volknandt Meiko

Subjects
Physics, QC1-999
Abstract

The neutron activation method is well-suited to investigate neutron-capture cross sections relevant for the main s-process component. Neutrons can be produced via the 7Li(p,n) reaction with proton energies of 1912 keV at e.g. Van de Graaff accelerators, which results in a quasi-Maxwellian spectrum of neutrons corresponding to a temperature of kBT = 25 keV. However, the weak s-process takes place in massive stars at temperatures between 25 and 90 keV. Simulations using the PINO code [2] suggest that a Maxwellian spectrum for higher energies, e.g. kBT = 90 keV, can be approximated by a linear combination of different neutron spectra. To validate the PINO code at proton energies Ep ≠ 1912 keV, neutron time-of-flight measurements were carried out at the PTB Ion Accelerator Facility (PIAF) at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany.

Published
2022
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3. Tests of Various Scintillator Detectors in Selected Mono-Energetic Neutron Beams

Author

Jančář Aleš, Čulen Jiří, Mravec Filip, Košťál Michal, Dlhopolček Daniel, Pirovano Elisa, Nolte Ralf, Cvachovec František, Přenosil Václav, and Matěj Zdeněk

Subjects
scintillation detectors, mono-energetic neutron sources, pulse-shape discrimination, fwhm, digital-signal processing, Physics, QC1-999
Abstract

In this paper we study quality of three types of organic scintillators stilbene, p-terphenyl and EJ-299-33. We used monoenergetic neutron fields with a wide range of neutron energies in PTB Braunschweig. All the tests were carried out with NGA-01 spectrometer. The results of the measurements are evaluated spectra from the spectrometer. We discuss the quality of each scintillator, such as the FWHM of the peaks.

Published
2021
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4. Neutron transmission measurements at nELBE

Author

Junghans Arnd, Beyer Roland, ClauBner Jürgen, Kögler Toni, Urlass Sebastian, Bemmerer Daniel, Ferrari Anna, Schwengner Ronald, Wagner Andreas, Dietz Mirco, Frotscher Axel, Grieger Marcel, Hensel Thomas, Koppitz Martina, Ludwig Felix, Turkat Steffen, Nolte Ralf, Pirovano Elisa, Kopecky Stefan, Nyman Markus, Plompen Arjan, Schillebeeckx Peter, Borris Erik, Reifarth René, Veltum Daniel, Weigand Mario, Glorius Jan, Görres Joachim, Oberlack Uwe, and Wenz Daniel

Subjects
Physics, QC1-999
Abstract

Neutron total cross sections are an important source of experimental data in the evaluation of neutron-induced cross sections. The sum of all neutron-induced reaction cross sections can be determined with a precision of a few per cent in a relative measurement. The neutron spectrum of the photoneutron source nELBE extends in the fast region from about 100 keV to 10 MeV and has favourable conditions for transmission measurements due to the low instantaneous flux of neutrons and low gamma-flash background. Several materials of interest (in part included in the CIELO evaluation or on the HPRL of OECD/NEA) have been investigated: 197Au [1, 2], natFe [2], natW [2], 238U, natPt, 4He, natO, natNe, natXe. For gaseous targets high pressure gas cells with flat end-caps have been built that hold up to 200 bar pressure. The experimental setup will be presented including results from several transmission experiments and the data analysis leading to the total cross sections will be discussed.

Published
2020
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5. Measurement of the angular distribution of neutrons scattered from deuterium below 3 MeV

Author

Pirovano Elisa, Nolte Ralf, Nyman Markus, and Plompen Arjan

Subjects
Physics, QC1-999
Abstract

The differential cross section of neutron scattering on deuterium was investigated in the energy range from 400 keV to 2.5 MeV using the recoil detection method, irradiating with monoenergetic neutrons a proportional counter filled with deuterated gases. Comparing simulations of the transport of neutrons and recoil nuclei in the detector to the experimental pulse-height distribution, it was possible to establish a procedure for the determination of the coefficients of the Legendre expansion of the n-d angular distribution.

Published
2020
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6. Neutron detection devices with 6LiF converter layers

Author

Finocchiaro Paolo, Cosentino Luigi, Meo Sergio Lo, Nolte Ralf, and Radeck Desiree

Subjects
Thermal neutron detectors, 3He replacement, 6LiF neutron converter, silicon detectors, Physics, QC1-999
Abstract

The demand for new thermal neutron detectors as an alternative to 3He tubes in research, industrial, safety and homeland security applications, is growing. These needs have triggered research and development activities about new generations of thermal neutron detectors, characterized by reasonable efficiency and gamma rejection comparable to 3He tubes. In this paper we show the state of art of a promising lowcost technique, based on commercial solid state silicon detectors coupled with thin neutron converter layers of 6LiF deposited onto carbon fiber substrates. Several configurations were studied with the GEANT4 simulation code, and then calibrated at the PTB Thermal Neutron Calibration Facility. The results show that the measured detection efficiency is well reproduced by the simulations, therefore validating the simulation tool in view of new designs. These neutron detectors have also been tested at neutron beam facilities like ISIS (Rutherford Appleton Laboratory, UK) and n_TOF (CERN) where a few samples are already in operation for beam flux and 2D profile measurements. Forthcoming applications are foreseen for the online monitoring of spent nuclear fuel casks in interim storage sites.

Published
2018
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7. Measurements of neutron scattering angular distributions with a new scintillator setup

Author

Pirovano Elisa, Beyer Roland, Junghans Arnd, Nolte Ralf, Nyman Markus, and Plompen Arjan

Subjects
Physics, QC1-999
Abstract

A new experimental setup for the measurement of neutron scattering cross sections and angular distributions is currently being developed at the neutron time-of-flight facility GELINA, at the JRC-Geel. Up to 32 liquid organic scintillators are employed for the detection of neutrons scattered from a sample of the investigated material. The differential cross section is measured at eight different angles, and the angle-integrated cross section is obtained from the differential data by numerical integration. Two experiments for the study of scattering on iron were carried out, one at GELINA and the other at nELBE (HZDR). The first results for the angular distributions of elastic scattering in the neutron energy range from 2 to 6 MeV are here presented and compared with evaluations from the major nuclear data libraries.

Published
2017
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8. Measurement of Neutron Activation Cross Sections on Mo isotopes in the Energy Range from 7 MeV to 15 MeV

Author

Semkova Valentina and Nolte Ralf

Subjects
Physics, QC1-999
Abstract

An experimental study of the 92Mo(n,p)92Nbm, 92Mo(n,α)89Zr, 95Mo(n,p)95Nbm, 95Mo(n,p)95Nb, 96Mo(n,p)96Nb, 97Mo(n,p)97Nb, 98Mo(n,p)98Nbm, 98Mo(n,a)95Zr, 100Mo(n,α) 97Zr, and 92Mo(n,2n)99Mo activation reaction cross sections were carried out in the 7-15 MeV energy range at the CV28 compact cyclotron at Physikalisch-Technische Bundesanstalt, Braunschweig. The PTB TOF spectrometer with a D(d,n) source is well suited for this difficult energy range were significant correction for non-monoenergetic neutrons have to be applied. Gamma-ray spectrometry was applied for the measurements of the activity of the reaction products.

Published
2014
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10. Absolute efficiency calibration of 6LiF-based solid state thermal neutron detectors

Author

Finocchiaro, Paolo, Cosentino, Luigi, Meo, Sergio Lo, Nolte, Ralf, and Radeck, Desiree

Subjects
Physics - Instrumentation and Detectors
Abstract

The demand for new thermal neutron detectors as an alternative to 3He tubes in research, industrial, safety and homeland security applications, is growing. These needs have triggered research and development activities about new generations of thermal neutron detectors, characterized by reasonable efficiency and gamma rejection comparable to 3He tubes. In this paper we show the state of the art of a promising low-cost technique, based on commercial solid state silicon detectors coupled with thin neutron converter layers of 6LiF deposited onto carbon fiber substrates. A few configurations were studied with the GEANT4 simulation code, and then calibrated at the PTB Thermal Neutron Calibration Facility. The results show that the measured detection efficiency is well reproduced by the simulations, therefore validating the simulation tool in view of new designs. These neutron detectors have also been tested at neutron beam facilities like ISIS (Rutherford Appleton Laboratory, UK) and n_TOF (CERN) where a few samples are already in operation for beam flux and 2D profile measurements. Forthcoming applications are foreseen for the online monitoring of spent nuclear fuel casks in interim storage sites.

Published
2018
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11. Study of the 15N(p,n)15O reaction as a monoenergetic neutron source for the measurement of differential scattering cross sections

Author

Poenitz, Erik, Nolte, Ralf, Schmidt, Dankwart, and Chen, Guochang

Subjects
Nuclear Experiment
Abstract

The 15N(p,n) reaction is a promising candidate for the production of monoenergetic neutrons with energies of up to 5.7 MeV at the facilities where the T(p,n)3He reaction cannot be used. The characteristic properties of this reaction were studied focusing on its suitability as a source of monoenergetic neutrons for the measurement of differential scattering cross sections in the neutron energy range of 2 MeV to 5 MeV. For this purpose differential and integral cross sections were measured and the choice of optimum target conditions was investigated. The reaction has already been used successfully to measure of elastic and inelastic neutron scattering cross sections for natPb in the energy range from 2 MeV to 4 MeV and for 209Bi and 181Ta at 4 MeV.

Published
2017
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13. Measurement of the <math><mrow><mmultiscripts><mi mathvariant='normal'>N</mi><mprescripts/><none/><mn>14</mn></mmultiscripts><mo>(</mo><mi>n</mi><mo>,</mo><mi>p</mi><mo>)</mo><mmultiscripts><mi mathvariant='normal'>C</mi><mprescripts/><none/><mn>14</mn></mmultiscripts></mrow></math> cross section at the CERN n_TOF facility from subthermal energy to 800 keV

Author

Torres-Sánchez, Pablo, Praena, Javier, Porras, Ignacio, Sabaté-Gilarte, Marta, Lederer-Woods, Claudia, Aberle, Oliver, Alcayne, Victor, Amaducci, Simone, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Babiano-Suarez, Victor, Bacak, Michael, Barbagallo, Massimo, Bečvář, František, Bellia, Giorgio, Berthoumieux, Eric, Billowes, Jon, Bosnar, Damir, Brown, Adam, Busso, Maurizio, Caamaño, Manuel, Caballero, Luis, Calviño, Francisco, Calviani, Marco, Cano-Ott, Daniel, Casanovas, Adria, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés, Guillem, Cortés-Giraldo, Miguel, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia-Anna, Diakaki, Maria, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Eleme, Zinovia, Fernández-Domínguez, Beatriz, Ferrari, Alfredo, Ferrer, Francisco Javier, Finocchiaro, Paolo, Furman, Valter, Göbel, Kathrin, Garg, Ruchi, Gawlik-Ramięga, Aleksandra, Geslot, Benoit, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel, González-Romero, Enrique, Guerrero, Carlos, Gunsing, Frank, Harada, Hideo, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Jericha, Erwin, Käppeler, Franz, Kadi, Yacine, Kimura, Atsushi, Kivel, Niko, Kokkoris, Michael, Kopatch, Yury, Krtička, Milan, Kurtulgil, Deniz, Ladarescu, Ion, Leeb, Helmut, Lerendegui-Marco, Jorge, Meo, Sergio Lo, Lonsdale, Sarah-Jane, Macina, Daniela, Manna, Alice, Martínez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio-Andrea, Mazzone, Annamaria, Mendoza, Emilio, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Mingrone, Federica, Musumarra, Agatino, Negret, Alexandru, Nolte, Ralf, Ogállar, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Persanti, Luciano, Quesada, José-Manuel, Radeck, Désirée, Ramos-Doval, Diego, Rauscher, Thomas, Reifarth, René, Rochman, Dimitri, Rubbia, Carlo, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Smith, Gavin, Sosnin, Nikolay, Stamatopoulos, Athanasios, Tagliente, Giuseppe, Tain, José, Talip, Zeynep, Tarifeño-Saldivia, Ariel, Tassan-Got, Laurent, Tsinganis, Andrea, Ulrich, Jiri, Urlass, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, Philip John, Wright, Tobias, Žugec, Petar, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and n_TOF

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract

International audience; Background: The N14(n,p)C14 reaction is of interest in neutron capture therapy, where nitrogen-related dose is the main component due to low-energy neutrons, and in astrophysics, where N14 acts as a neutron poison in the s process. Several discrepancies remain between the existing data obtained in partial energy ranges: thermal energy, keV region, and resonance region.Purpose: We aim to measure the N14(n,p)C14 cross section from thermal to the resonance region in a single measurement for the first time, including characterization of the first resonances, and provide calculations of Maxwellian averaged cross sections (MACS).Method: We apply the time-of-flight technique at Experimental Area 2 (EAR-2) of the neutron time-of-flight (n_TOF) facility at CERN. B10(n,α)Li7 and U235(n,f) reactions are used as references. Two detection systems are run simultaneously, one on beam and another off beam. Resonances are described with the R-matrix code sammy.Results: The cross section was measured from subthermal energy to 800 keV, resolving the first two resonances (at 492.7 and 644 keV). A thermal cross section was obtained (1.809±0.045 b) that is lower than the two most recent measurements by slightly more than one standard deviation, but in line with the ENDF/B-VIII.0 and JEFF-3.3 evaluations. A 1/v energy dependence of the cross section was confirmed up to tens of keV neutron energy. The low energy tail of the first resonance at 492.7 keV is lower than suggested by evaluated values, while the overall resonance strength agrees with evaluations.Conclusions: Our measurement has allowed determination of the N14(n,p) cross section over a wide energy range for the first time. We have obtained cross sections with high accuracy (2.5%) from subthermal energy to 800 keV and used these data to calculate the MACS for kT=5 to kT=100 keV.

Published
2023

15. Measurement of the $^{14}$N(n,p)$^{14}$C cross section at the CERN n_TOF facility from sub-thermal energy to 800 keV

Author

Torres-Sánchez, Pablo, Praena, Javier, Porras, Ignacio, Sabaté-Gilarte, Marta, Lederer-Woods, Claudia, Aberle, Oliver, Alcayne, Victor, Amaducci, Simone, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Babiano-Suarez, Victor, Bacak, Michael, Barbagallo, Massimo, Bečvář, František, Bellia, Giorgio, Berthoumieux, Eric, Billowes, Jon, Bosnar, Damir, Brown, Adam, Busso, Maurizio, Caamaño, Manuel, Caballero, Luis, Calviño, Francisco, Calviani, Marco, Cano-Ott, Daniel, Casanovas, Adria, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés, Guillem, Cortés-Giraldo, Miguel, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia-Anna, Diakaki, Maria, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Eleme, Zinovia, Fernández-Domínguez, Beatriz, Ferrari, Alfredo, Ferrer, Francisco Javier, Finocchiaro, Paolo, Furman, Valter, Göbel, Kathrin, Garg, Ruchi, Gawlik-Ramięga, Aleksandra, Geslot, Benoit, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel, González-Romero, Enrique, Guerrero, Carlos, Gunsing, Frank, Harada, Hideo, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Jericha, Erwin, Käppeler, Franz, Kadi, Yacine, Kimura, Atsushi, Kivel, Niko, Kokkoris, Michael, Kopatch, Yury, Krtička, Milan, Kurtulgil, Deniz, Ladarescu, Ion, Leeb, Helmut, Lerendegui-Marco, Jorge, Meo, Sergio Lo, Lonsdale, Sarah-Jane, Macina, Daniela, Manna, Alice, Martínez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio-Andrea, Mazzone, Annamaria, Mendoza, Emilio, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Mingrone, Federica, Musumarra, Agatino, Negret, Alexandru, Nolte, Ralf, Ogállar, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Persanti, Luciano, Quesada, José-Manuel, Radeck, Désirée, Ramos-Doval, Diego, Rauscher, Thomas, Reifarth, René, Rochman, Dimitri, Rubbia, Carlo, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Smith, Gavin, Sosnin, Nikolay, Stamatopoulos, Athanasios, Tagliente, Giuseppe, Tain, José, Talip, Zeynep, Tarifeño-Saldivia, Ariel, Tassan-Got, Laurent, Tsinganis, Andrea, Ulrich, Jiri, Urlass, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, PhilipJohn, Woods, Philip John, Wright, Tobias, Žugec, Petar, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), n_TOF, European Project: 677497,H2020,ERC-2015-STG,DoRES(2016), HEP, INSPIRE, and Direct measurements of key nuclear Reactions for the creation of Elements in Stars - DoRES - - H20202016-06-01 - 2021-05-31 - 677497 - VALID

Subjects
[PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], FOS: Physical sciences, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), nucl-ex, Nuclear Experiment
Abstract

Background: The $^{14}$N(n,p)$^{14}$C reaction is of interest in neutron capture therapy, where nitrogen-related dose is the main component due to low-energy neutrons, and in astrophysics, where 14N acts as a neutron poison in the s-process. Several discrepancies remain between the existing data obtained in partial energy ranges: thermal energy, keV region and resonance region. Purpose: Measuring the 14N(n,p)14C cross section from thermal to the resonance region in a single measurement for the first time, including characterization of the first resonances, and providing calculations of Maxwellian averaged cross sections (MACS). Method: Time-of-flight technique. Experimental Area 2 (EAR-2) of the neutron time-of-flight (n_TOF) facility at CERN. $^{10}$B(n,${\alpha}$)$^7$Li and $^{235}$U(n,f) reactions as references. Two detection systems running simultaneously, one on-beam and another off-beam. Description of the resonances with the R-matrix code sammy. Results: The cross section has been measured from sub-thermal energy to 800 keV resolving the two first resonances (at 492.7 and 644 keV). A thermal cross-section (1.809$\pm$0.045 b) lower than the two most recent measurements by slightly more than one standard deviation, but in line with the ENDF/B-VIII.0 and JEFF-3.3 evaluations has been obtained. A 1/v energy dependence of the cross section has been confirmed up to tens of keV neutron energy. The low energy tail of the first resonance at 492.7 keV is lower than suggested by evaluated values, while the overall resonance strength agrees with evaluations. Conclusions: Our measurement has allowed to determine the $^{14}$N(n,p) cross-section over a wide energy range for the first time. We have obtained cross-sections with high accuracy (2.5 %) from sub-thermal energy to 800 keV and used these data to calculate the MACS for kT = 5 to kT = 100 keV., Comment: 18 pages, 15 figures, 4 tables

Published
2022
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16. Neutron transmission measurements at nELBE.

Author

Junghans, Arnd, Beyer, Roland, ClauBner, Jürgen, Kögler, Toni, Urlass, Sebastian, Bemmerer, Daniel, Ferrari, Anna, Schwengner, Ronald, Wagner, Andreas, Dietz, Mirco, Frotscher, Axel, Grieger, Marcel, Hensel, Thomas, Koppitz, Martina, Ludwig, Felix, Turkat, Steffen, Nolte, Ralf, Pirovano, Elisa, Kopecky, Stefan, and Nyman, Markus

Subjects
NEUTRONS, NUCLEAR cross sections, MEASUREMENT, DATA analysis, NEUTRONS spectra
Abstract

Neutron total cross sections are an important source of experimental data in the evaluation of neutron-induced cross sections. The sum of all neutron-induced reaction cross sections can be determined with a precision of a few per cent in a relative measurement. The neutron spectrum of the photoneutron source nELBE extends in the fast region from about 100 keV to 10 MeV and has favourable conditions for transmission measurements due to the low instantaneous flux of neutrons and low gamma-flash background. Several materials of interest (in part included in the CIELO evaluation or on the HPRL of OECD/NEA) have been investigated: 197Au [1, 2], natFe [2], natW [2], 238U, natPt, 4He, natO, natNe, natXe. For gaseous targets high pressure gas cells with flat end-caps have been built that hold up to 200 bar pressure. The experimental setup will be presented including results from several transmission experiments and the data analysis leading to the total cross sections will be discussed. [ABSTRACT FROM AUTHOR]

Published
2022
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17. Destruction of the cosmic γ-ray emitter 26Al in massive stars: study of the key 26Al(n,p) reaction

Author

Lederer-Woods, Claudia, Woods, Philip John, Davinson, Thomas, Kahl, David, Lonsdale, Sarah Jane, Aberle, Oliver, Amaducci, Simone, Andrzejewski, Józef, Audouin, Laurent, Bacak, Michael, Balibrea-Correa, Javier, Barbagallo, Massimo, Bečvář, František, Berthoumieux, Eric, Billowes, Jon, Bosnar, Damir, Brown, Adam, Caamaño, Manuel, Calviño, Francisco, Calviani, Marco, Cano-Ott, Daniel, Cardella, Roberto, Casanovas, Adria, Cerutti, Francesco, Chen, Y. H., Chiaveri, Enrico, Colonna, Nicola, Cortés, Guillem, Cortés-Giraldo, Miguel Antonio, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia Anna, Diakaki, Maria, Domingo-Pardo, Cesar, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Fernández-Domínguez, Beatriz, Ferrari, Alfredo, Ferreira, Paulo, Ferrer, Francesc J., Finocchiaro, Paolo, Furman, Valter, Göbel, Kathrin, García, Aczel Regino, Gawlik, Aleksandra, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel F., González-Romero, Enrique, Griesmayer, Erich, Guerrero, Carlos, Gunsing, Frank, Harada, Hideo, Heinitz, Stephan, Heyse, Jan, Jenkins, David G., Jericha, Erwin, Käppeler, Franz, Kadi, Yacine, Kalamara, Antigoni, Kavrigin, Pavel, Kimura, Atsushi, Kivel, Nikolai, Kokkoris, Michael, Krtička, Milan, Kurtulgil, Deniz, Leal-Cidoncha, E., Leeb, Helmut, Lerendegui-Marco, Jorge, Lo Meo, Sergio, Macina, Daniela, Manna, Alice, Marganiec, Justyna, Martínez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Maugeri, Emilio-Andrea, Mazzone, Annamaria, Mendoza, Emilio, Mengoni, Alberto, Milazzo, Paolo M., Mingrone, Federica, Musumarra, Agatino, Negret, Alexandru, Nolte, Ralf, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Porras, Ignacio, Praena, Javier, Quesada, José-Manuel, Radeck, Desiree, Rauscher, Thomas, Reifarth, René, Rubbia, Carlo, Ryan, James A., Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Sedyshev, Pavel V., Smith, Alastair G., Sosnin, Nikolay V., Stamatopoulos, Athanasios, Tagliente, Giuseppe, Tain, José L., Tarifeño-Saldivia, Ariel, Tassan-Got, Laurent, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Warren, Stuart, Weß, Christina, Wright, Tobias, Žugec, Petar, and n_TOF Collaboration

Subjects
ddc:530
Abstract

The 26Al(n,p)26Mg reaction is the key reaction impacting on the abundances of the cosmic γ-ray emitter 26Al produced in massive stars and impacts on the potential pollution of the early solar system with 26Al by asymptotic giant branch stars. We performed a measurement of the 26Al(n,p)26Mg cross section at the high-flux beam line EAR-2 at the n_TOF facility (CERN). We report resonance strengths for eleven resonances, nine being measured for the first time, while there is only one previous measurement for the other two. Our resonance strengths are significantly lower than the only previous values available. Our cross-section data range to 150 keV neutron energy, which is sufficient for a reliable determination of astrophysical reactivities up to 0.5 GK stellar temperature.

Published
2021

21. Investigation of the 7Li(p,n) neutron fields at high energies.

Author

Brückner, Benjamin, Erbacher, Philipp, Göbel, Kathrin, Heftrich, Tanja, Khasawneh, Kafa, Kurtulgil, Deniz, Langer, Christoph, Nolte, Ralf, Reich, Markus, Reifarth, René, Thomas, Benedikt, Weigand, Mario, Wiescher, Michael, and Volknandt, Meiko

Subjects
NEUTRON capture, VAN de Graaff generator, PROTONS, RELATIVISTIC electrodynamics, SIMULATION methods & models
Abstract

The neutron activation method is well-suited to investigate neutron-capture cross sections relevant for the main s-process component. Neutrons can be produced via the 7Li(p,n) reaction with proton energies of 1912 keV at e.g. Van de Graaff accelerators, which results in a quasi-Maxwellian spectrum of neutrons corresponding to a temperature of kBT = 25 keV. However, the weak s-process takes place in massive stars at temperatures between 25 and 90 keV. Simulations using the PINO code [2] suggest that a Maxwellian spectrum for higher energies, e.g. kBT = 90 keV, can be approximated by a linear combination of different neutron spectra. To validate the PINO code at proton energies Ep ≠ 1912 keV, neutron time-of-flight measurements were carried out at the PTB Ion Accelerator Facility (PIAF) at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany. [ABSTRACT FROM AUTHOR]

Published
2022
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28. Neutron detection devices with 6LiF converter layers.

Author

Finocchiaro, Paolo, Cosentino, Luigi, Meo, Sergio Lo, Nolte, Ralf, and Radeck, Desiree

Subjects
NEUTRON counters, THERMAL neutron capture, SILICON detectors, CARBON fibers, GAMMA rays
Abstract

The demand for new thermal neutron detectors as an alternative to 3He tubes in research, industrial, safety and homeland security applications, is growing. These needs have triggered research and development activities about new generations of thermal neutron detectors, characterized by reasonable efficiency and gamma rejection comparable to 3He tubes. In this paper we show the state of art of a promising lowcost technique, based on commercial solid state silicon detectors coupled with thin neutron converter layers of 6 LiF deposited onto carbon fiber substrates. Several configurations were studied with the GEANT4 simulation code, and then calibrated at the PTB Thermal Neutron Calibration Facility. The results show that the measured detection efficiency is well reproduced by the simulations, therefore validating the simulation tool in view of new designs. These neutron detectors have also been tested at neutron beam facilities like ISIS (Rutherford Appleton Laboratory, UK) and n_TOF (CERN) where a few samples are already in operation for beam flux and 2D profile measurements. Forthcoming applications are foreseen for the online monitoring of spent nuclear fuel casks in interim storage sites. [ABSTRACT FROM AUTHOR]

Published
2018
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30. Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector.

Author

Reginatto, Marcel, Gagnon-Moisan, Francis, Araque, Jorge Guerrero, Nolte, Ralf, Zbořil, Miroslav, and Zimbal, Andreas

Subjects
NEUTRON counters, BAYESIAN analysis, CHEMICAL vapor deposition, MATRICES (Mathematics), SINGLE crystals, DIAMOND crystals
Abstract

Detectors made from artificial chemical vapor deposition (CVD) single crystal diamond are very promising candidates for applications where high resolution neutron spectrometry in very high neutron fluxes is required, for example in fusion research. We propose a Bayesian method to estimate the neutron response function of the detector for a continuous range of neutron energies (in our case, 10 MeV ≤ En ≤ 16 MeV) based on a few measurements with quasi-monoenergetic neutrons. This method is needed because a complete set of measurements is not available and the alternative approach of using responses based on Monte Carlo calculations is not feasible. Our approach uses Bayesian signal-background separation techniques and radial basis function interpolation methods. We present the analysis of data measured at the PTB accelerator facility PIAF. The method is quite general and it can be applied to other particle detectors with similar characteristics. [ABSTRACT FROM AUTHOR]

Published
2015
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42. Measurement of235U,238U,209Bi andnatPb Fission Cross Sections using Quasi-monoenergetic Neutrons with Energies from 30 MeV to 150 MeV

Author

Nolte, Ralf, primary, Allie, M. Saalih, additional, Binns, Peter J., additional, Brooks, Frank D., additional, Buffler, Andy, additional, Dangendorf, Volker, additional, Langen, Katia, additional, Meulders, Jean-Pierre, additional, Newhauser, Wayne D., additional, Roos, Frank, additional, and Schuhmacher, Helmut, additional

Published
2002
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43. Radionuclide Production from Lead by Neutron-Induced Reactions up to 175 MeV

Author

Glasser, Wolfgang, primary, Michel, Rolf, additional, Neumann, Sonja, additional, Schuhmacher, Helmut, additional, Dangendorf, Volker, additional, Nolte, Ralf, additional, Herpers, Ulrich, additional, Smirnov, Andrey N., additional, Ryzhov, Igor, additional, Prokofiev, Alexander V., additional, Malmborg, Petter, additional, Kollár, Daniel, additional, and Meulders, Jean-Pierre, additional

Published
2002
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44. HINDAS A European Nuclear Data Program for Accelerator-Driven Systems

Author

Koning, Arjan, primary, Beijers, Hans, additional, Benlliure, Jose, additional, Bersillon, Olivier, additional, Blomgren, Jan, additional, Cugnon, Joseph, additional, Duijvestijn, Marieke, additional, Eudes, Philippe, additional, Filges, Detlef, additional, Haddad, Ferid, additional, Hilaire, Stephane, additional, Lebrun, Claude, additional, Lecolley, Francois-Rene, additional, Leray, Sylvie, additional, Meulders, Jean-Pierre, additional, Michel, Rolf, additional, Neef, Ralf, additional, Nolte, Ralf, additional, Olsson, Nils, additional, Ostendorf, Reint, additional, Ramstroem, Elisabet, additional, Schmidt, Karl-Heinz, additional, Schuhmacher, Helmut, additional, Slypen, Isabelle, additional, Synal, Hans-Arno, additional, and Weinreich, Regin, additional

Published
2002
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45. Neutron-Induced Fission Cross Sections of Nuclei in the Vicinity of 208Pb at Incident Energies below 60 MeV.

Author

Ryzhov, Igor V., Tutin, Gennady A., Eismont, Vilen P., Mitryukhin, Andrey G., Oplavin, Valery S., Soloviev, Sergey M., Meulders, Jean-Pierre, El Masri, Youssef, Keutgen, Thomas, Prieels, René, and Nolte, Ralf

Subjects
NEUTRONS, PARTICLES (Nuclear physics), NEUTRON beams, NEUTRAL beams, NUCLEAR physics, PHYSICS
Abstract

Neutron-induced fission cross sections of 205Tl, 204, 206, 207, 208Pb, and 209Bi have been measured at incident energies of 32.8, 45.3, and 59.9 MeV. The measurements were performed at the Louvain-la-Neuve neutron beam facility using the 7Li (p, n) reaction as neutron source. Fission fragments were detected with a multi-section Frisch-gridded ionization chamber (MFGIC). Neutron fluence measurements were based on the 238U(n, f) reaction. The neutron fluence monitoring procedure was asserted by crosscheck measurement, in which the 59.9-MeV neutron beam fluence was simultaneously determined with the MFGIC and with a fission chamber monitor calibrated relative to a proton-recoil telescope. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2005
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47. Measurement of 235U, 238U, 209Bi and natPb Fission Cross Sections using Quasi-monoenergetic Neutrons with Energies from 30 MeV to 150 MeV

Author

Nolte, Ralf, Allie, M. Saalih, Binns, Peter J., Brooks, Frank D., Buffler, Andy, Dangendorf, Volker, Langen, Katia, Meulders, Jean-Pierre, Newhauser, Wayne D., Roos, Frank, and Schuhmacher, Helmut

Abstract

The cross sections for neutron induced fission of 235U, 238U, 209Bi and natPb were measured in the energy range from 30 MeV to 150 MeV using parallel-plate ionization chambers. Proton recoil telescopes and a 238U ionization chamber were employed for the determination of the incident neutron fluence. With the exception of a few deviating data points, the experimental results for 235U(n, f), 238U(n, f) and 209Bi(n, f) are close to the recommended cross sections. For natPb(n, f) the measured cross sections are about 30% lower than the results of a recent evaluation.

Published
2002
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49. Messung von Wirkungsquerschnitten für die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der 15N(p,n)-Reaktion als Neutronenquelle

Author

Pönitz, Erik, Nolte, Ralf, Freiesleben, Hartwig, Klein, Horst, Technische Universität Dresden, and Physikalisch-Technische Bundesanstalt

Subjects
neutron, cross section, time-of-flight, Neutronen, Wirkungsquerschnitte, Flugzeitspektrometrie, ddc:530
Abstract

In zukünftigen kerntechnischen Anlagen können die Materialien Blei und Bismut eine größere Rolle spielen als heute. Für die Planung dieser Anlagen werden verlässliche Wirkungsquerschnittsdaten benötigt. Insbesondere der Neutronentransport in einem Blei-Spallationstarget eines beschleunigergetriebenen unterkritischen Reaktors hängt stark von den inelastischen Streuquerschnitten im Energiebereich von 0,5 MeV bis 6 MeV ab. In den vergangenen 20 Jahren wurden elastische und inelastische Neutronenstreuquerschnitte mit hoher Präzision für eine Vielzahl von Elementen am PTB-Flugzeitspektrometer gemessen. Zur Erzeugung der Neutronen wurde hauptsächlich die D(d,n)-Reaktion genutzt. Aufgrund des Q-Wertes der Reaktion und der verfügbaren Deuteronenenergien können Neutronen im Energiebereich von 6 MeV bis 16 MeV erzeugt werden. Die Messung von Wirkungsquerschnitten bei niedrigeren Energien erfordert somit die Verwendung einer anderen neutronenerzeugenden Reaktion. Hierfür wurde die 15N(p,n)15O-Reaktion ausgewählt, da sie die Erzeugung monoenergetischer Neutronen bis zu einer Energie von 5,7 MeV erlaubt. In dieser Arbeit wird die 15N(p,n)-Reaktion auf ihre Eignung als Quelle monoenergetischer Neutronen in Streuexperimenten untersucht. Die Untersuchung der Reaktion beinhaltet die Messung von differentiellen Wirkungsquerschnitten für ausgewählte Energien und die Auswahl von optimalen Targetbedingungen. Differentielle elastische und inelastische Neutronenstreuquerschnitte wurden unter Anwendung der Flugzeitmethode für Blei bei vier Energien zwischen 2 MeV und 4 MeV gemessen. Eine Bleiprobe mit natürlicher Isotopenzusammensetzung wurde verwendet. Für den Nachweis der gestreuten Neutronen wurden NE213 Flüssigszintillatoren verwendet, deren Nachweiswahrscheinlichkeit gut bekannt ist. Winkelintegrierte Wirkungsquerschnitte wurden mit einem Legendre-Polynomfit unter Verwendung der Methode der kleinsten Quadrate bestimmt. Zusätzlich erfolgten Messungen für die isotopenreinen Streuproben 209Bi und 181Ta bei 4 MeV Neutronenenergie. Die Ergebnisse werden mit denen früherer Experimente und aktuellen Evaluationen verglichen. In future nuclear facilities, the materials lead and bismuth can play a more important role than in today’s nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6MeV to 16MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The 15N(p,n)15O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the 15N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2MeV to 4MeV incident neutron energy using the time-offlight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure 209Bi and 181Ta samples at 4MeV incident neutron energy. Results are compared with other measurements and recent evaluations.

Published
2010

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