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1. Status report of the n_TOF facility after the 2nd CERN long shutdown period

Author

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

Subjects
Neutron time of flight, Spallation target, Nuclear astrophysics, Neutron physics, Neutron induced fission, Neutron reactions, Physics, QC1-999, Optics. Light, QC350-467, Descriptive and experimental mechanics, QC120-168.85
Abstract

Abstract During the second long shutdown period of the CERN accelerator complex (LS2, 2019-2021), several upgrade activities took place at the n_TOF facility. The most important have been the replacement of the spallation target with a next generation nitrogen-cooled lead target. Additionally, a new experimental area, at a very short distance from the target assembly (the NEAR Station) was established. In this paper, the core commissioning actions of the new installations are described. The improvement in the n_TOF infrastructure was accompanied by several detector development projects. All these upgrade actions are discussed, focusing mostly on the future perspectives of the n_TOF facility. Furthermore, some indicative current and future measurements are briefly reported.

Published
2023
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2. Status report of the n_TOF facility after the 2nd CERN long shutdown period.

Author

Patronis, N., Mengoni, A., Goula, S., Aberle, O., Alcayne, V., Altieri, S., Amaducci, S., Andrzejewski, J., Babiano-Suarez, V., Bacak, M., Balibrea Correa, J., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Beyer, R., Boromiza, M., Bosnar, D., Caamaño, M., and Calviño, F.

Subjects
NUCLEAR astrophysics
Abstract

During the second long shutdown period of the CERN accelerator complex (LS2, 2019-2021), several upgrade activities took place at the n_TOF facility. The most important have been the replacement of the spallation target with a next generation nitrogen-cooled lead target. Additionally, a new experimental area, at a very short distance from the target assembly (the NEAR Station) was established. In this paper, the core commissioning actions of the new installations are described. The improvement in the n_TOF infrastructure was accompanied by several detector development projects. All these upgrade actions are discussed, focusing mostly on the future perspectives of the n_TOF facility. Furthermore, some indicative current and future measurements are briefly reported. [ABSTRACT FROM AUTHOR]

Published
2023
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3. A Forward Analytic Model of Neutron Time-of-Flight Signals for Inferring Ion Temperatures from MagLIF Experiments.

Author

Weaver, Colin, Cooper, Gary, Perfetti, Christopher, Ampleford, David, Chandler, Gordon, Knapp, Patrick, Mangan, Michael, and Styron, Jedediah

Subjects
INERTIAL confinement fusion, NEUTRON transport theory, ION temperature, BOLTZMANN'S equation, NEUTRONS, MONTE Carlo method, TRANSPORT equation
Abstract

A forward analytic model is required to rapidly simulate the neutron time-of-flight (nToF) signals that result from magnetized liner inertial fusion (MagLIF) experiments at Sandia's Z Pulsed Power Facility. Various experimental parameters, such as the burn-weighted fuel-ion temperature and liner areal density, determine the shape of the nToF signal and are important for characterizing any given MagLIF experiment. Extracting these parameters from measured nToF signals requires an appropriate analytic model that includes the primary deuterium-deuterium neutron peak, once-scattered neutrons in the beryllium liner of the MagLIF target, and direct beamline attenuation. Mathematical expressions for this model were derived from the general-geometry time- and energy-dependent neutron transport equation with anisotropic scattering. Assumptions consistent with the time-of-flight technique were used to simplify this linear Boltzmann transport equation into a more tractable form. Models of the uncollided and once-collided neutron scalar fluxes were developed for one of the five nToF detector locations at the Z-Machine. Numerical results from these models were produced for a representative MagLIF problem and found to be in good agreement with similar neutron transport simulations. Twenty experimental MagLIF data sets were analyzed using the forward models, which were determined to only be significantly sensitive to the ion temperature. The results of this work were also found to agree with values obtained separately using a zero scatter analytic model and a high-fidelity Monte Carlo simulation. Inherent difficulties in this and similar techniques are identified, and a new approach forward is suggested. [ABSTRACT FROM AUTHOR]

Published
2022
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6. A Pulse-Multiplication Proposal for MIRACLES, the Neutron TOF-Backscattering Instrument at the European Spallation Source

Author

Félix J. Villacorta, Heloisa N. Bordallo, and Masatoshi Arai

Subjects
neutron instrumentation, inelastic neutron scattering, fixed-energy window scan, neutron time of flight, pulse multiplication, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

The fixed-energy window scan approach, for both elastic and inelastic modes, is a valuable tool to discriminate between motions activated when dynamical phase transitions occur in a sample as a function of time, temperature, pressure, electrical field or illumination. Considering that, on one hand, such variations can generate a weak signal, and on the other, high data throughput makes it possible to screen many samples during a beam time, pulse multiplication is an ideal strategy to optimize the intensity of the analyzed signal. To ensure this capability, a proposal for a future upgrade of MIRACLES, the neutron time-of-flight backscattering spectrometer at the European Spallation Source (ESS) under construction in Lund, is reported in this article. The concept for a new chopper layout relies on the extraction of several elastic pulses, ensuring an increase in the neutron total elastic intensity hitting the sample. This proposal can be extended to the inelastic counterpart. The premise is to maintain the original beamline layout without modification, either of the guide sections or of the current chopper layout of MIRACLES, thereby guaranteeing that minimal changes and impact will occur during the proposed upgrade. However, this also presents a significant challenge, namely, to achieve an efficient pulse multiplication within the width and the length of the guide and within the rising/decay time of the pulses. With the concept presented here, an increase in elastic intensity by a factor of 2.8 was obtained. This is analogous to performing elastic fixed window (EFW) measurements with an ESS source operating at 14 MW, widening considerably the performance capabilities of MIRACLES. The knowledge generated here is also valuable for the design of scientific instruments for the next generation of low-energy, accelerator-driven neutron sources.

Published
2021
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7. An alternative methodology for high counting-loss corrections in neutron time-of-flight measurements.

Author

Stamatopoulos, A., Diakaki, M., Tsinganis, A., Colonna, N., Gunsing, F., Tassan-Got, L., Kokkoris, M., Kalamara, A., Žugec, P., Patronis, N., Sabate-Gilarte, M., and Vlastou, R.

Subjects
*NEUTRON temperature, *TIME-of-flight spectroscopy, *NEUTRON flux, *CHEMICAL kinetics, *NEUTRON counters
Abstract

Abstract In counting experiments associated with pulsed sources, a high data collection rate can lead to considerably large counting losses, especially in the case of spallation Time-of-Flight facilities equipped with medium and short flight paths where the research interest is focused on higher neutron energies where counting losses can be quite large due to the higher neutron flux, the more compressed time frame compared to the one on lower energies and the higher cross-section depending on the reaction. Examples of such measurements are the neutron induced fission experiments at the new experimental area EAR-2 at the n_TOF facility at CERN. Although analytical expressions to account for this inefficiency exist in literature, the introduced corrections are not always sufficient to retrieve the true reaction rate, therefore a different approach is mandatory. This work explores the possibility to quantify the counting losses using detector emulation devices and exponential fits in waiting time distributions. The methodology is benchmarked in the test case of the standard 238U(n,f) cross-section with reference to 235U(n,f) for bandwidths up to 1.9 MHz and counting losses that exceed 60%. [ABSTRACT FROM AUTHOR]

Published
2019
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8. Study on collimator design for Neutron Science Facility of RAON accelerator complex.

Author

Lee, Eunjoong, Lee, Cheol-Woo, Yang, Sung-Chul, Lee, Young-Ouk, and Cho, Gyuseong

Subjects
*HEAVY ion accelerators, *COLLIMATORS, *NEUTRON beams, *GRAPHITE, *SYNCHRONIZATION
Abstract

The RAON heavy ion accelerator complex is under development for the Rare Isotope Science Project (RISP) in Korea. The Neutron Science Facility (NSF) in RAON will perform Time of Flight (TOF) experiments in order to measure cross section data of fast neutrons. Fast neutrons are produced from a graphite target irradiated by a 53 MeV of deuteron beam. Consequently, a collimator that provides a highly focused neutron beam to the TOF system while reducing the background in the TOF hall should be considered. The collimator was designed by optimizing several design parameters such as the beam channel diameter, beam channel shape, and collimator type. Additionally, for the safety of workers during the operation of the NSF, an activation analysis was carried out. As a result, the final design of the collimator for the RAON NSF has a 4 m length, and channel of 0.5/2 cm in the entry/exit radius in a conical-opened shape. Materials were arranged in a ring type by setting 1 cm of the iron inside, and 20 cm of 5% borated polyethylene outside. With the final design of the collimator, a 95.7% background reduction was achieved while maintaining the original neutron beam intensity. The shut-down dose rate inside the TOF room satisfies the exposure limit [ABSTRACT FROM AUTHOR]

Published
2018
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9. Nuclear science experiments with a bright neutron source from fusion reactions on the OMEGA Laser System.

Author

Forrest, C.J., Knauer, J.P., Schroeder, W.U., Glebov, V.Yu., Radha, P.B., Regan, S.P., Sangster, T.C., Sickles, M., Stoeckl, C., and Szczepanski, J.

Subjects
*NUCLEAR science, *NEUTRON sources, *NUCLEAR fusion, *PICOSECOND pulses, *TIME-of-flight spectrometry
Abstract

Subnanosecond impulses of 1 0 13 to 1 0 14 neutrons, produced in direct-drive laser inertial confinement fusion implosions, have been used to irradiate deuterated targets at the OMEGA Laser System (Boehly et al., 1997). The target compounds include heavy water (D 2 O) and deuterated benzene (C 6 D 6 ). Yields and energy spectra of neutrons from D(n,2n)p to study the breakup reaction have been measured at a forward angle of θ lab = 3 . 5 ∘ ± 3 .5° with a sensitive, high-dynamic-range neutron time-of-flight spectrometer to infer the double-differential breakup cross section d 2 σ /d E d Ω for 14-MeV D–T fusion neutrons. [ABSTRACT FROM AUTHOR]

Published
2018
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10. RESONEUT: A detector system for spectroscopy with (d,n) reactions in inverse kinematics.

Author

Baby, L.T., Kuvin, S.A., Wiedenhöver, I., Anastasiou, M., Caussyn, D., Colbert, K., Quails, N., and Gay, D.

Subjects
*ATOMIC spectroscopy, *RADIOACTIVE nuclear beams, *KINEMATIC chains, *SPECTRUM analysis, *ASTROPHYSICAL radiation
Abstract

The resoneut detector setup is described, which was developed for resonance spectroscopy using (d,n) reactions with radioactive beams in inverse kinematics and at energies around the Coulomb barrier. The goal of experiments with this setup is to determine the spectrum and proton-transfer strengths of the low-lying resonances, which have an impact on astrophysical reaction rates. The setup is optimized for l = 0 proton transfers in inverse kinematics, for which most neutrons are emitted at backward angles with energies in the 80–300 keV range. The detector system is comprised of 9 p-terphenyl scintillators as neutron detectors, two annular silicon-strip detectors for light charged particles, one position-resolving gas ionization chamber for heavy ion detection, and a barrel of NaI-detectors for the detection of γ -rays. The detector commissioning and performance characteristics are described with an emphasis on the neutron-detector components. [ABSTRACT FROM AUTHOR]

Published
2018
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11. A direct method for unfolding the resolution function from measurements of neutron induced reactions.

Author

Žugec, P., Colonna, N., Sabate-Gilarte, M., Vlachoudis, V., Massimi, C., Lerendegui-Marco, J., Stamatopoulos, A., Bacak, M., and Warren, S.G.

Subjects
*LOW-energy nuclear reactions, *COMPUTER memory management, *DECOMPOSITION method, *MATRIX inversion, *UNCERTAINTY
Abstract

The paper explores the numerical stability and the computational efficiency of a direct method for unfolding the resolution function from the measurements of the neutron induced reactions. A detailed resolution function formalism is laid out, followed by an overview of challenges present in a practical implementation of the method. A special matrix storage scheme is developed in order to facilitate both the memory management of the resolution function matrix, and to increase the computational efficiency of the matrix multiplication and decomposition procedures. Due to its admirable computational properties, a Cholesky decomposition is at the heart of the unfolding procedure. With the smallest but necessary modification of the matrix to be decomposed, the method is successfully applied to system of 1 0 5 × 1 0 5 . However, the amplification of the uncertainties during the direct inversion procedures limits the applicability of the method to high-precision measurements of neutron induced reactions. [ABSTRACT FROM AUTHOR]

Published
2017
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12. Neutron imaging detector with 2 [formula omitted] spatial resolution based on event reconstruction of neutron capture in gadolinium oxysulfide scintillators.

Author

Hussey, Daniel S., LaManna, Jacob M., Baltic, Elias, and Jacobson, David L.

Subjects
*SCINTILLATORS, *NEUTRON capture, *NEUTRON counters, *SULFIDES, *IMAGE processing
Abstract

We report on efforts to improve the achievable spatial resolution in neutron imaging by centroiding the scintillation light from gadolinium oxysulfide scintillators. The current state-of-the-art neutron imaging spatial resolution is about 10 μ m , and many applications of neutron imaging would benefit from at least an order of magnitude improvement in the spatial resolution. The detector scheme that we have developed magnifies the scintillation light from a gadolinium oxysulfide scintillator, calculates the center of mass of the scintillation event, resulting in an event-based imaging detector with spatial resolution of about 2 μ m . [ABSTRACT FROM AUTHOR]

Published
2017
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13. Gating of charge sensitive preamplifiers for the use at pulsed radiation sources.

Author

Urlaß, S., (0000-0001-7703-2471) Junghans, A., Mingrone, F., Peronnard, P., (0000-0001-5522-0666) Stach, D., Tassan-Got, L., Weinberger, D., The, Ntof Collaboration, Urlaß, S., (0000-0001-7703-2471) Junghans, A., Mingrone, F., Peronnard, P., (0000-0001-5522-0666) Stach, D., Tassan-Got, L., Weinberger, D., and The, Ntof Collaboration

Abstract

The development of a switch circuit to gate charge sensitive preamplifiers for use at pulsed radiation sources will be presented.This development was used for the 16O(n,alpha)13C reaction measurement with a Double Frisch Grid Ionization Chamber (DFGIC) at the neutron time-of-flight facility CERN nTOF in Geneva, Switzerland. The so-called gamma-flash, which is produced in the spallation target of the nTOF facility can saturate charge sensitive preamplifiers and prevent signals from being registered in the detection system. The switch circuit made it possible for the first time to perform a measurement with the DFGIC with gamma-flash gated off at nTOF in November 2018. Nano-second gating of charge sensitive preamplifiers has a wide range of applicability at pulsed radiation sources, where short burst of radiation must be gated off to avoid saturation, e.g. with HPGe detectors for gamma-ray detection. Nano-second gating requires the stray-capacitance of the wideband reflective switch to be compensated to avoid a strong signal during the switch operation. Spectral analysis of the switch circuit shows that additional noise is insignificant.

Published
2021

14. A Pulse-Multiplication Proposal for MIRACLES, the Neutron TOF-Backscattering Instrument at the European Spallation Source

Author

Villacorta, Felix J., Bordallo, Heloisa N., Arai, Masatoshi, Villacorta, Felix J., Bordallo, Heloisa N., and Arai, Masatoshi

Abstract

The fixed-energy window scan approach, for both elastic and inelastic modes, is a valuable tool to discriminate between motions activated when dynamical phase transitions occur in a sample as a function of time, temperature, pressure, electrical field or illumination. Considering that, on one hand, such variations can generate a weak signal, and on the other, high data throughput makes it possible to screen many samples during a beam time, pulse multiplication is an ideal strategy to optimize the intensity of the analyzed signal. To ensure this capability, a proposal for a future upgrade of MIRACLES, the neutron time-of-flight backscattering spectrometer at the European Spallation Source (ESS) under construction in Lund, is reported in this article. The concept for a new chopper layout relies on the extraction of several elastic pulses, ensuring an increase in the neutron total elastic intensity hitting the sample. This proposal can be extended to the inelastic counterpart. The premise is to maintain the original beamline layout without modification, either of the guide sections or of the current chopper layout of MIRACLES, thereby guaranteeing that minimal changes and impact will occur during the proposed upgrade. However, this also presents a significant challenge, namely, to achieve an efficient pulse multiplication within the width and the length of the guide and within the rising/decay time of the pulses. With the concept presented here, an increase in elastic intensity by a factor of 2.8 was obtained. This is analogous to performing elastic fixed window (EFW) measurements with an ESS source operating at 14 MW, widening considerably the performance capabilities of MIRACLES. The knowledge generated here is also valuable for the design of scientific instruments for the next generation of low-energy, accelerator-driven neutron sources.

Published
2021

15. Gating of charge sensitive preamplifiers for the use at pulsed radiation sources

Author

Urlass, Sebastian, Junghans, Arnd, Mingrone, Federica, Peronnard, Paul, Stach, Daniel, Tassan-Got, Laurent, Weinberger, David, 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), and n_TOF

Subjects
Gated preamplifier, [formula omitted]-flash, γ -flash, Neutron time of flight, Switch, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Detectors and Experimental Techniques, n_TOF facility
Abstract

International audience; The development of a switch circuit to gate charge sensitive preamplifiers for use at pulsed radiation sources will be presented. This development was used for the 16 O(n, α ) 13 C reaction measurement with a Double Frisch Grid Ionization Chamber (DFGIC) at the neutron time-of-flight facility CERN n_TOF in Geneva, Switzerland. Intense instantaneous radiation which is produced in the spallation target of the n_TOF facility ( γ -flash) can saturate charge sensitive preamplifiers and prevent signals from being registered in the detection system. The switch circuit made it possible for the first time to perform a measurement with the DFGIC with γ -flash gated off at n_TOF. Nano-second gating of charge sensitive preamplifiers has a wide range of applicability at pulsed radiation sources, where short bursts of radiation must be gated off to avoid saturation, e.g. with HPGe detectors for γ -ray detection. Nano-second gating requires the stray-capacitance of the wideband reflective switch to be compensated to avoid a strong signal during the switch operation. Spectral analysis of the switch circuit shows that additional noise is insignificant.

Published
2021
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16. GEANT4 simulation of the neutron background of the C6D6 set-up for capture studies at n_TOF.

Author

Žugec, P., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., 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., and Chiaveri, E.

Subjects
*NEUTRONS, *SIMULATION methods & models, *COMPUTER software, *PULSE height analyzers, *PHYSICS experiments, *NUCLEAR cross sections
Abstract

Abstract: The neutron sensitivity of the C6D6 detector setup used at n_TOF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has been implemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with a natC sample, showing an excellent agreement above 1keV. At lower energies, an additional component in the measured natC yield has been discovered, which prevents the use of natC data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron background for two different samples are demonstrating the important role of accurate simulations of the neutron background in capture cross-section measurements. [Copyright &y& Elsevier]

Published
2014
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17. Measurement of the α ratio and (n, γ) cross section of 235U from 0.2 to 200 eV at n_TOF

Author

Balibrea-Correa, J., Mendoza, E., Cano-Ott, D., González, E., Capote, R., 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., Calviani, M., Calviño, F., 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., 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., 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., 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
PRIRODNE ZNANOSTI. Fizika, α ratio, 235U, Physics, ddc:530, n_TOF, neutron time of flight, NATURAL SCIENCES. Physics
Abstract

We measured the neutron capture-to-fission cross-section ratio (α ratio) and the capture cross section of $^{235}$U between 0.2 and 200 eV at the n_TOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the n_TOF BaF$_{2}$ Total Absorption Calorimeter (TAC), used for detection of γ rays, in combination with a set of micromegas detectors used as fission tagging detectors. The energy dependence of the capture cross section was obtained with help of the $^{6}$Li(n,t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the $^{235}$U(n,f) cross section between 7.8 and 11 eV was then used for its absolute normalization. The α ratio, obtained with slightly higher statistical fluctuations, was determined directly, without need for any reference cross section. To perform the analysis of this measurement we developed a new methodology to correct the experimentally observed effect that the probabilities of detecting a fission reaction in the TAC and the micromegas detectors are not independent. The results of this work have been used in a new evaluation of $^{235}$U performed within the scope of the Collaborative International Evaluated Library Organisation (CIELO) Project, and are consistent with the ENDF/B-VIII.0 and JEFF-3.3 capture cross sections below 4 eV and above 100 eV. However, the measured capture cross section is on average 10% larger between 4 and 100 eV.

Published
2020
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18. Measurement of the 154Gd(n,γ) cross section and its astrophysical implications

Author

Z. Talip, A. S. Brown, J. Lerendegui-Marco, S. Amaducci, Alexandru Negret, P. Vaz, F. Käppeler, A. Masi, R. Wynants, Alberto Ventura, D. G. Jenkins, M. Sabaté-Gilarte, E. Mendoza, A. Kimura, G. Vannini, O. Aberle, V. Babiano-Suarez, Stefan Kopecky, A. Manna, A. Pavlik, A. Stamatopoulos, M. Diakaki, M. Mastromarco, C. Domingo-Pardo, V. Variale, Dimitri Rochman, S. Heinitz, M. A. Cortés-Giraldo, Z. Eleme, Emilio Andrea Maugeri, M. Kokkoris, Anton Wallner, D. Macina, B. Fernández-Domíngez, E. Jericha, S. Urlass, Mario Barbagallo, Alfredo Ferrari, Paolo Finocchiaro, Maurizio Busso, G. Alaerts, A. Oprea, J. Heyse, D. M. Castelluccio, R. Mucciola, F. Calviño, D. Schumann, Ariel Tarifeño-Saldivia, S. J. Lonsdale, A. Musumarra, G. Cortes, E. Chiaveri, D. Cano-Ott, I. Ferro-Gonçalves, P. M. Milazzo, Ignacio Porras, Rene Reifarth, Giulia Clai, S. Valenta, A. Gawlik, N. Patronis, P. Schillebeeckx, Javier Praena, S. Lo Meo, Carlos Guerrero, J. Perkowski, P. Torres-Sánchez, F. Bečvář, A. Saxena, Marco Calviani, Alberto Mengoni, I. Ladarescu, A. G. Smith, R. Garg, J. Billowes, J. M. Quesada, E. González-Romero, L. Tassan-Got, F. Gunsing, Francesca Matteucci, I. Duran, M. Dietz, Diego Vescovi, Sergio Cristallo, F. Mingrone, J. Andrzejewski, Cristian Massimi, Philip Woods, V. Bécares, L. Caballero, Claudia Lederer-Woods, R. Dressler, V. Vlachoudis, R. Vlastou, Ralf Nolte, M. Caamaño, Deniz Kurtulgil, L. A. Damone, Damir Bosnar, Y. Kadi, K. Göbel, F. Cerutti, V. Alcayne, T. Wright, V. Furman, Y. Kopatch, N. V. Sosnin, Simone Gilardoni, Annamaria Mazzone, Petar Žugec, J. Ulrich, D. Radeck, E. Berthoumieux, J. L. Tain, Niko Kivel, G. Bellia, F. Ogállar, Y. H. Chen, C. Rubbia, G. Tagliente, D. Ramos Doval, A. Casanovas, L. Cosentino, P. F. Mastinu, M. Krtička, T. Martinez, A. Tsinganis, Luciano Piersanti, Nicola Colonna, E. Dupont, M. Bacak, T. Glodariu, L. Audouin, V. Michalopoulou, ITA, GBR, FRA, DEU, ESP, AUT, BEL, HRV, JPN, GRC, IND, POL, CZE, CHE, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, 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), Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Mazzone, A., Cristallo, S., Aberle, O., Alaerts, G., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Becares, V., Becvar, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A. S., Busso, M., Caamano, M., Caballero, L., Calviani, M., Calvino, F., Cano-Ott, D., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chen, Y. H., Chiaveri, E., Clai, G., Colonna, N., Cortes, G. P., Cortes-Giraldo, M. A., Cosentino, L., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Duran, I., Eleme, Z., Fernandez-Domingez, B., Ferrari, A., Ferro-Goncalves, I., Finocchiaro, P., Furman, V., Garg, R., Gawlik, A., Gilardoni, S., Glodariu, T., Gobel, K., Gonzalez-Romero, E., Guerrero, C., Gunsing, F., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Kadi, Y., Kappeler, F., Kimura, A., Kivel, N., Kokkoris, M., Kopatch, Y., Kopecky, S., Krticka, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S. -J., Macina, D., Manna, A., Martinez, T., Masi, A., Massimi, C., Mastinu, P. F., Mastromarco, M., Matteucci, F., Maugeri, E., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Mucciola, R., Musumarra, A., Negret, A., Nolte, R., Ogallar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Piersanti, L., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Ramos Doval, D., Reifarth, R., Rochman, D., Rubbia, C., Sabate-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, Z., Tarifeno-Saldivia, A. E., Tassan-Got, L., Torres-Sanchez, P., Tsinganis, A., Ulrich, J., Urlass, S., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wynants, R., Wright, T. J., Zugec, P., Mazzone A., Cristallo S., Aberle O., Alaerts G., Alcayne V., Amaducci S., Andrzejewski J., Audouin L., Babiano-Suarez V., Bacak M., Barbagallo M., Becares V., Becvar F., Bellia G., Berthoumieux E., Billowes J., Bosnar D., Brown A.S., Busso M., Caamano M., Caballero L., Calviani M., Calvino F., Cano-Ott D., Casanovas A., Castelluccio D.M., Cerutti F., Chen Y.H., Chiaveri E., Clai G., Colonna N., Cortes G.P., Cortes-Giraldo M.A., Cosentino L., Damone L.A., Diakaki M., Dietz M., Domingo-Pardo C., Dressler R., Dupont E., Duran I., Eleme Z., Fernandez-Domingez B., Ferrari A., Ferro-Goncalves I., Finocchiaro P., Furman V., Garg R., Gawlik A., Gilardoni S., Glodariu T., Gobel K., Gonzalez-Romero E., Guerrero C., Gunsing F., Heinitz S., Heyse J., Jenkins D.G., Jericha E., Kadi Y., Kappeler F., Kimura A., Kivel N., Kokkoris M., Kopatch Y., Kopecky S., Krticka M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lo Meo S., Lonsdale S.-J., Macina D., Manna A., Martinez T., Masi A., Massimi C., Mastinu P.F., Mastromarco M., Matteucci F., Maugeri E., Mendoza E., Mengoni A., Michalopoulou V., Milazzo P.M., Mingrone F., Mucciola R., Musumarra A., Negret A., Nolte R., Ogallar F., Oprea A., Patronis N., Pavlik A., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J.M., Radeck D., Ramos Doval D., Reifarth R., Rochman D., Rubbia C., Sabate-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Smith A.G., Sosnin N., Stamatopoulos A., Tagliente G., Tain J.L., Talip Z., Tarifeno-Saldivia A.E., Tassan-Got L., Torres-Sanchez P., Tsinganis A., Ulrich J., Urlass S., Valenta S., Vannini G., Variale V., Vaz P., Ventura A., Vescovi D., Vlachoudis V., Vlastou R., Wallner A., Woods P.J., Wynants R., Wright T.J., and Zugec P.

Subjects
Nuclear and High Energy Physics, Gd, Neutron time of flight, Física::Física de partícules [Àrees temàtiques de la UPC], Nuclear physics, Neutrons--Captura, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, Neutron time of flightn, 01 natural sciences, 7. Clean energy, Neutrons--Capture, Cross section (physics), Nucleosynthesis, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, 0103 physical sciences, Neutron cross section, ddc:530, Nuclear Physics - Experiment, Spallation, Neutron, n_TOF, Nuclear Experiment, 010306 general physics, 154Gd, Physics, Scintillation, 154 Gd, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, s process, Atmospheric temperature range, lcsh:QC1-999, NATURAL SCIENCES. Physics, PRIRODNE ZNANOSTI. Fizika, Neutron time-of-flight, Física nuclear, s-process, lcsh:Physics
Abstract

The isotope used in this research was supplied by the United States Department of Energy Office of Science by the Isotope Program in the Office of Nuclear Physics., The neutron capture cross section of 154Gd was measured from 1 eV to 300 keV in the experimental area located 185 m from the CERN n_TOF neutron spallation source, using a metallic sample of gadolinium, enriched to 67% in 154Gd. The capture measurement, performed with four C6D6 scintillation detectors, has been complemented by a transmission measurement performed at the GELINA time-of-flight facility (JRC-Geel), thus minimising the uncertainty related to sample composition. An accurate Maxwellian averaged capture cross section (MACS) was deduced over the temperature range of interest for s process nucleosynthesis modelling. We report a value of 880(50) mb for the MACS at kT = 30 keV, significantly lower compared to values available in literature. The new adopted 154Gd(n,γ ) cross section reduces the discrepancy between observed and calculated solar s-only isotopic abundances predicted by s-process nucleosynthesis models., EUFRAT open access programme of the Joint Research Centre at Geel

Published
2020
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19. Thick target neutron yield from 145MeV 19F+27Al system.

Author

C., Sunil, Bandyopadhyay, T., Nandy, M., Suman, Vitisha, Paul, S., Nanal, V., Pillay, R.G., and Sarkar, P.K.

Subjects
*NEUTRONS, *ALUMINUM compounds, *NEUTRON temperature, *PHOTONS, *NUCLEAR reactions, *NUCLEAR physics experiments
Abstract

Abstract: The double differential neutron energy distribution has been measured for the 19F+27Al system at 145MeV projectile energy. The time of flight technique was used to measure the energy while pulse shape discrimination has been used to separate the neutrons from photons. The results are compared with the statistical nuclear reaction model codes PACE and EMPIRE. The PACE code appears to predict the slope and the end point energy of the experimental spectra fairly well but over predicts the values. The slope obtained from the EMPIRE calculations appears to be harder while the values being closer to the experimental results. The yield from the Hauser–Feshbach based compound nucleus model calculations agree reasonably well with the experimental results at the backward angles but not in the forward directions. The energy integrated angular distribution from 145MeV projectiles show an enhanced emission in the forward angles compared to the similar results from 110MeV projectiles. This analysis suggests some contribution from the pre-equilibrium emissions from the system at the higher projectile energy. [Copyright &y& Elsevier]

Published
2013
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20. Analysis of the FIC detector data at the n_TOF facility.

Author

Karadimos, D., Vlastou, R., Ioannides, K., Assimakopoulos, P., Tsagas, N., Pavlopoulos, P., Karamanis, D., Papachristodoulou, C., Stamoulis, K., Vlachoudis, V., Cennini, P., Ketlerov, V., and Konovalov, V.

Subjects
*IONIZATION chambers, *NUCLEAR counters, *TIME-of-flight mass spectrometry, *FISSION cross sections, *ANALOG-to-digital converters, *NUCLEAR energy
Abstract

Abstract: Fission cross-section measurements with the Fast Ionization Chamber (FIC) at the CERN n_TOF facility were challenged by intense signals due to γ-rays and ultra-relativistic particles from the impact of the 20GeV proton pulses on the neutron spallation target. A method for analyzing the data taken with Flash Analog to Digital Converters (FADC) was developed to treat these problems in an automated way to provide a reliable background subtraction and a fit routine for identifying fission events even at high energies. The analysis is illustrated at the example of the fission cross-section of 238U relative to that of 235U in the energy range from 40keV to 300MeV. [Copyright &y& Elsevier]

Published
2010
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21. Machine learning based event classification for the energy-differential measurement of the [formula omitted]C(n,p) and [formula omitted]C(n,d) reactions.

Author

Žugec, P., Barbagallo, M., Andrzejewski, J., Perkowski, J., Colonna, N., Bosnar, D., Gawlik, A., Sabaté-Gilarte, M., Bacak, M., Mingrone, F., and Chiaveri, E.

Subjects
*NEUTRON measurement, *CLASSIFICATION, *MACHINE learning, *TELESCOPES
Abstract

The paper explores the feasibility of using machine learning techniques, in particular neural networks, for classification of the experimental data from the joint nat C(n,p) and nat C(n,d) reaction cross section measurement from the neutron time of flight facility n_TOF at CERN. Each relevant Δ E − E pair of strips from two segmented silicon telescopes is treated separately and afforded its own dedicated neural network. An important part of the procedure is a careful preparation of training datasets, based on the raw data from Geant4 simulations. Instead of using these raw data for the training of neural networks, we divide a relevant 3-parameter space into discrete voxels, classify each voxel according to a particle/reaction type and submit these voxels to a training procedure. The classification capabilities of the structurally optimized and trained neural networks are found to be superior to those of the manually selected cuts. [ABSTRACT FROM AUTHOR]

Published
2022
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22. n&#95:TOF experiment: Neutron beam profile and fast neutron background determination, using CR-39 passive neutron detector.

Author

Savvidis, I., Lampoudis, C., Papaevangelou, T., and Eleftheriadis, C.

Subjects
*PARTICLES (Nuclear physics), *DETECTORS, *ENGINEERING instruments, *NEUTRONS
Abstract

Abstract: A passive neutron detector, based on CR-39 plastic with the appropriate converter, was used in order to determine the neutron beam profile of n_TOF project (CERN-PS213 experiment). The main goal of the task was to have a clear view of neutrons’ spatial distribution that reach the target''s surface, at the end of the neutron beam line. Results reveal a slight shift (mm order of magnitude) along x- and -axes. Secondly, a slightly different detector setup was used to indicate the fast neutron scattered background component in the experimental area. In most cases values were found below or just above detection limit. Measurements were carried out at the n_TOF facility (CERN—Geneva). [Copyright &y& Elsevier]

Published
2007
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23. High luminosity time of flight with polarisation analysis: CeCu6

Author

Harker, S.J., Hicks, T.J., Kennedy, S.J., and Yu, Dehong

Subjects
*ENGINEERING instruments, *ENERGY storage, *ENERGY transfer, *FORCE & energy
Abstract

Abstract: The magnetic excitation spectrum of the heavy fermion system CeCu6 has been obtained by pseudo-randomly chopping the polarisation of the beam on LONGPOL and measuring the time of flight with polarisation analysis before the detectors. Separation of the magnetic part of the spectrum was made by changing the polarisation direction at the specimen. This method achieves a greater luminosity at the specimen compared with conventional methods at the expense of a background proportional to the total scattering from the specimen. The form of the spectrum is as expected with two transitions and considerable inelastic intensity centred on zero energy transfer. The crystal field spectrum of the Ce3+ ion is considerably broadened by the Kondo nature of the system. An analysis of the experimental accuracy was made based on the statistical variation between the runs which make up the experiment. LONGPOL is a very slow instrument, based as it is on a thermal source with an incident wavelength of 3.6Å. The demonstrated possibility to obtain a spectrum incorporating polarisation analysis provides a basis to evaluate the usefulness of future implementation. [Copyright &y& Elsevier]

Published
2007
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24. Proton-recoil detectors for time-of-flight measurements of neutrons with kinetic energies from some tens of keV to a few MeV

Author

Beyer, R., Grosse, E., Heidel, K., Hutsch, J., Junghans, A.R., Klug, J., Légrády, D., Nolte, R., Röttger, S., Sobiella, M., and Wagner, A.

Subjects
*DETECTORS, *NEUTRONS, *STOPPING power (Nuclear physics), *ELECTRON accelerators
Abstract

Abstract: For experiments at the superconducting electron accelerator ELBE, where neutrons in the kinetic energy region from some tens of keV to a few MeV will be produced by bremsstrahlung, neutron-time-of-flight detectors have been developed. These detectors are made from the plastic scintillator material EJ-200. Efficiency calibration showed more than 10% efficiency for kinetic energies down to 30keV. The calibration was done at the “accelerator facility for fast neutron research” at Physikalisch-Technische Bundesanstalt in Braunschweig, using pulsed quasi-monoenergetic neutron fields with a well-determined fluence. The low detection threshold was obtained by coincident readout of two Hamamatsu R2059-01 photomultiplier tubes per scintillator and by triggering just below the single-photo-electron peak of these photomultiplier tubes, which additionally gives a well-reproduceable detection threshold. [Copyright &y& Elsevier]

Published
2007
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25. Analysis of resolution defects in the SANS spectrometer at the NUR reactor

Author

Meftah, B. and Zidi, T.

Subjects
*COLLIMATORS, *OPTICAL instruments, *SPECTROMETERS, *SPECTRUM analysis instruments
Abstract

Abstract: The effects of the collimating system and of the dispersion in neutron wavelength on scattered intensities are reviewed in this paper for the SANS spectrometer at the NUR research reactor. It is found that the design parameters of the spectrometer will induce in general a non-negligible smearing effect in the measured (experimental) intensities. The introduction of adequate de-smearing schemes in the data treatment step is required in order to render the experimental data useful. [Copyright &y& Elsevier]

Published
2005
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26. Precision Neutron Polarimetry for Neutron Beta Decay.

Author

Penttila, S. I. and Bowman, J. D.

Subjects
SPECTROMETERS, NEUTRONS, POLARIMETRY, COLD neutrons, NEUTRON beams
Abstract

The abBA collaboration is developing a new type of field-expansion spectrometer for a measurement of the three correlation coefficients a, A, and B and the shape parameter b. The measurement of A and requires precision neutron polarimetry. We will polarize a pulsed cold neutron beam from the SNS using a 3 He neutron spin filter. The well-known polarizing cross section for n-³He has a 1/v dependence, where v is the neutron velocity, which is used to determine the absolute beam polarization through a time-of-flight (TOF) measurement. We show that by measuring the TOF dependence of A and B, the coefficients and the neutron polarization can be determined with a small loss of the statistical precision and with negligible systematic error. We conclude that it is possible to determine the neutron polarization averaged over a long run in the neutron beta decay experiment with a statistical error less than 10-4. We discuss various sources of systematic uncertainty in the measurement of A and B and conclude that the fractional systematic errors are less than 2 x10-4. [ABSTRACT FROM AUTHOR]

Published
2005
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27. An alternative methodology for high counting-loss corrections in neutron time-of-flight measurements

Author

A. Kalamara, R. Vlastou, M. Sabaté-Gilarte, A. Stamatopoulos, Petar Žugec, M. Diakaki, A. Tsinganis, Nicola Colonna, F. Gunsing, L. Tassan-Got, M. Kokkoris, N. Patronis, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), n_TOF, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear and High Energy Physics, Neutron time of flight, Dead-time, Nuclear engineering, Pulse reconstruction, 01 natural sciences, Lead (geology), 0103 physical sciences, Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Detectors and Experimental Techniques, 010306 general physics, Instrumentation, Pile-up, Physics, Data collection, 010308 nuclear & particles physics, fungi, food and beverages, n_TOF facility, NATURAL SCIENCES. Physics, Detector emulation, PRIRODNE ZNANOSTI. Fizika, Time of flight, Dead-time, Pile-up, n_TOF facility, Neutron time of flight, Detector emulation, Pulse reconstruction, Waiting time distribution, Waiting time distribution
Abstract

International audience; In counting experiments associated with pulsed sources, a high data collection rate can lead to considerably large counting losses, especially in the case of spallation Time-of-Flight facilities equipped with medium and short flight paths where the research interest is focused on higher neutron energies where counting losses can be quite large due to the higher neutron flux, the more compressed time frame compared to the one on lower energies and the higher cross-section depending on the reaction. Examples of such measurements are the neutron induced fission experiments at the new experimental area EAR-2 at the n_TOF facility at CERN. Although analytical expressions to account for this inefficiency exist in literature, the introduced corrections are not always sufficient to retrieve the true reaction rate, therefore a different approach is mandatory. This work explores the possibility to quantify the counting losses using detector emulation devices and exponential fits in waiting time distributions. The methodology is benchmarked in the test case of the standard 238U(n,f) cross-section with reference to 235U(n,f) for bandwidths up to 1.9 MHz and counting losses that exceed 60%.

Published
2019
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28. A direct method for unfolding the resolution function from measurements of neutron induced reactions

Author

Petar Žugec, M. Bacak, J. Lerendegui-Marco, Nicola Colonna, Vasilis Vlachoudis, Cristian Massimi, M. Sabaté-Gilarte, S. G. Warren, A. Stamatopoulos, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Žugec, P., Colonna, N., Sabate-Gilarte, M., Vlachoudis, V., Massimi, C., Lerendegui-Marco, J., Stamatopoulos, A., Bacak, M., and Warren, S. G.

Subjects
Nuclear and High Energy Physics, [ INFO ] Computer Science [cs], Neutron time of flight, Other Fields of Physics, FOS: Physical sciences, Unfolding, 01 natural sciences, Resolution function, [ PHYS.PHYS.PHYS-DATA-AN ] Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], physics.data-an, Nuclear magnetic resonance, 0103 physical sciences, Neutron, [INFO]Computer Science [cs], 010306 general physics, Instrumentation, unfolding, Nuclear and High Energy Physic, Physics, 010308 nuclear & particles physics, Direct method, Computational Physics (physics.comp-ph), NATURAL SCIENCES. Physics, Matrix multiplication, n_TOF facility, 3. Good health, Computational physics, Computing and Computers, PRIRODNE ZNANOSTI. Fizika, Formalism (philosophy of mathematics), physics.comp-ph, Physics - Data Analysis, Statistics and Probability, resolution function, resolution function, unfolding, Cholesky decomposition, neutron time of flight, n_TOF facility, neutron time of flight, Cholesky decomposition, Physics - Computational Physics, Data Analysis, Statistics and Probability (physics.data-an), [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], Numerical stability
Abstract

The paper explores the numerical stability and the computational efficiency of a direct method for unfolding the resolution function from the measurements of the neutron induced reactions. A detailed resolution function formalism is laid out, followed by an overview of challenges present in a practical implementation of the method. A special matrix storage scheme is developed in order to facilitate both the memory management of the resolution function matrix, and to increase the computational efficiency of the matrix multiplication and decomposition procedures. Due to its admirable computational properties, a Cholesky decomposition is at the heart of the unfolding procedure. With the smallest but necessary modification of the matrix to be decomposed, the method is successfully applied to system of $10^5\times10^5$. However, the amplification of the uncertainties during the direct inversion procedures limits the applicability of the method to high-precision measurements of neutron induced reactions., 12 pages, 5 figures

Published
2017
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29. A synchronization method for the multi-channel silicon telescope.

Author

Žugec, P., Barbagallo, M., Andrzejewski, J., Perkowski, J., Colonna, N., Bosnar, D., Gawlik, A., Sabaté-Gilarte, M., Bacak, M., Mingrone, F., and Chiaveri, E.

Subjects
*SYNCHRONIZATION, *SILICON, *AUTOMATIC timers, *SILICON solar cells, *INFORMATION resources
Abstract

A simple method is presented for the simultaneous off-line synchronization of the digitally recorded data-streams from a multi-channel silicon telescope. The method is based both on the synchronization between the separate pairs of silicon strips and on the synchronization relative to an external timing device. Though only a reduced subset of these constraints is necessary in ideal circumstances, it is shown that this minimal set of conditions may not be sufficient for adequate synchronization in all cases. All available sources of information are therefore considered, in order to constrain the final synchronization as well as possible. [ABSTRACT FROM AUTHOR]

Published
2020
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30. A suite of neutron time-of-flight detectors to measure hot-spot motion in direct-drive inertial confinement fusion experiments on OMEGA.

Author

Mannion, O.M., Knauer, J.P., Glebov, V.Yu., Forrest, C.J., Liu, A., Mohamed, Z.L., Romanofsky, M.H., Sangster, T.C., Stoeckl, C., and Regan, S.P.

Subjects
*INERTIAL confinement fusion, *NEUTRON counters, *NEUTRON temperature, *VELOCITY measurements, *MOTION, *ION temperature
Abstract

A suite of six neutron time of flight detectors capable of measuring the primary DT neutron energy spectrum has recently been completed on the OMEGA Laser System. The detectors are positioned along multiple quasi-orthogonal lines of sight (LOS's) in either a stand-alone, collinear, or antipodal configuration. The collinear detector configuration enables one to measure the neutron velocity along the detector LOS independent of the neutron-production history, while the antipodal detector configuration enables one to directly measure of the hot-spot velocity along the detector axis and Gamow velocity shift due to the plasma ion temperature. Using these six measurements of the primary DT neutron energy spectrum, the neutron-averaged hot-spot velocity and Gamow velocity shift of DT fusion neutrons have been measured in cryogenic experiments on OMEGA for the first time. The detector suite is operable between DT neutron yields of 1 × 1013 to 2 × 1014 with an uncertainty of ∼ 14 km/s in the neutron-averaged hot-spot velocity measurement. [ABSTRACT FROM AUTHOR]

Published
2020
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31. Measurement of the 154Gd(n,γ) cross section and its astrophysical implications.

Author

Mazzone, A., Cristallo, S., Aberle, O., Alaerts, G., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Bécares, V., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A.S., Busso, M., and Caamaño, M.

Subjects
*NEUTRON capture, *SCINTILLATION counters, *NUCLEOSYNTHESIS, *NEUTRON sources, *GADOLINIUM, *MEASUREMENT
Abstract

The neutron capture cross section of 154Gd was measured from 1 eV to 300 keV in the experimental area located 185 m from the CERN n_TOF neutron spallation source, using a metallic sample of gadolinium, enriched to 67% in 154Gd. The capture measurement, performed with four C 6 D 6 scintillation detectors, has been complemented by a transmission measurement performed at the GELINA time-of-flight facility (JRC-Geel), thus minimising the uncertainty related to sample composition. An accurate Maxwellian averaged capture cross section (MACS) was deduced over the temperature range of interest for s process nucleosynthesis modelling. We report a value of 880(50) mb for the MACS at k T = 30 keV, significantly lower compared to values available in literature. The new adopted 154Gd(n, γ) cross section reduces the discrepancy between observed and calculated solar s-only isotopic abundances predicted by s-process nucleosynthesis models. [ABSTRACT FROM AUTHOR]

Published
2020
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32. A direct method for unfolding the resolution function from measurements of neutron induced reactions

Author

Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Croatian Science Foundation, European Commission (EC), Žugec, P., Colonna, Nicola, Sabate Gilarte, M., Vlachoudis, V., Massimi, C., Lerendegui Marco, Jorge, Warren, S. G., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Croatian Science Foundation, European Commission (EC), Žugec, P., Colonna, Nicola, Sabate Gilarte, M., Vlachoudis, V., Massimi, C., Lerendegui Marco, Jorge, and Warren, S. G.

Abstract

The paper explores the numerical stability and the computational efficiency of a direct method for unfolding the resolution function from the measurements of the neutron induced reactions. A detailed resolution function formalism is laid out, followed by an overview of challenges present in a practical implementation of the method. A special matrix storage scheme is developed in order to facilitate both the memory management of the resolution function matrix, and to increase the computational efficiency of the matrix multiplication and decomposition procedures. Due to its admirable computational properties, a Cholesky decomposition is at the heart of the unfolding procedure. With the smallest but necessary modification of the matrix to be decomposed, the method is successfully applied to system of 105 × 105 . However, the amplification of the uncertainties during the direct inversion procedures limits the applicability of the method to high-precision measurements of neutron induced reactions.

Published
2017

33. 7Be(n, α)4He Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN

Author

Barbagallo, M., Bosnar, Damir, and Žugec, Petar

Subjects
PRIRODNE ZNANOSTI. Fizika, 7Be(n, α)4He reaction, Cosmological Lithium Problem, neutron time of flight, n_TOF, Nuclear Experiment, NATURAL SCIENCES. Physics
Abstract

The energy-dependent cross section of the 7Be(n, α)4He reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of 7Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure 7Be, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two Si-7Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.

Published
2016
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34. A series of neutron time of flight method applications on the China Advanced Research Reactor.

Author

Yu, Zhouxiang, Li, Tianfu, Liang, Feng, Wang, Zijun, Li, Bonan, Liu, Rongdeng, Tian, Lichao, Wu, Liqi, Zhang, Li, Liu, Yuntao, and Chen, Dongfeng

Subjects
*SMALL-angle neutron scattering, *RESEARCH reactors, *SMALL-angle scattering, *TIME series analysis, *FLIGHT, *NEUTRON sources
Abstract

The advantages of time of flight method enable it to be widely used on stationary reactors. In this study, we reported several typical applications of time of flight method on the China Advanced Research Reactor (CARR). First, a new solution is designed to measure the beam characteristics including wavelengths, wavelength resolution rates and intensities of HOPG(002) monochromator for the unfiltered and filtered cases. Second, the changes in neutron wavelength spectra on the cross section of curved neutron guide CNGB end were examined and studied. It can be concluded that evident shape changes between neutron wavelength spectra along horizontal direction are mainly caused by the horizontal curving of curved neutron guide and dips at other wavelengths apart from 4 Å are mainly caused by small radius of curvature of curved neutron guide. Third, based on neutron velocity selector of small angle neutron scattering instrument at CARR, a calibration instrument is designed, and calibration experiments are conducted and simulated. The results indicate that the discrepancy between the experimental wavelength resolution rate and the theoretical one is caused by beam divergence linked with the critical reflection angle of neutron guide coating and the difference between experimental wavelength and the theoretical one is caused by the shape change of source neutron wavelength spectrum. These findings are reported here for the first time. [ABSTRACT FROM AUTHOR]

Published
2020
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35. Fast neutron measurements at the nELBE time-of-flight facility

Author

Roland Beyer, Andreas Wagner, A. R. Junghansa, T. Kögler, Ralph Massarczyk, E. Grosse, R. Hannaske, and Ronald Schwengner

Subjects
QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Neutron scattering, 01 natural sciences, 7. Clean energy, Neutron time-of-flight scattering, Nuclear physics, 0103 physical sciences, Neutron cross section, fission, Neutron, 010306 general physics, Nuclear Experiment, total cross section, Physics, 010308 nuclear & particles physics, transmission, Nuclear data, inelastic scattering, Neutron temperature, nELBE, Neutron source, neutron time of flight, Neutron moderator
Abstract

The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf has been rebuilt. A new enlarged experimental hall with a flight path of up to 10 m is available for neutron time-of-flight experiments in the fast energy range from about 50 keV to 10 MeV. nELBE is intended to deliver nuclear data of fast neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. The experimental programme consists of transmission measurements of neutron total cross sections, elastic and inelastic scattering cross section measurements, and neutron induced fission cross sections. The inelastic scattering to the first few excited states in 56 Fe was investigated by measuring the gamma production cross section with an HPGe detector. The neutron induced fission of 242 Pu was studied using fast ionisation chambers with large homogeneous actinide deposits.

Published
2015

36. Integral cross section measurement of the12C(n,p)12B reaction

Author

Žugec, Petar, Colonna, Nicola, Bosnar, Damir, Ventura, A., Altstadt, Sebastian, Andrzejewski, Józef, Audouin, Ludmila, Barbagallo, Massimo, Bécares, Vicente, Berthoumieux, Eric, Brugger, Matthias, Calviani, Marco, Calviño Tavares, Francisco, Cano Ott, Daniel, Riego Pérez, Albert, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, and Universitat Politècnica de Catalunya. NERG - Grup de Recerca d'Enginyeria Nuclear

Subjects
Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Integral cross-sections, Model prediction, Neutron time of flight, Reaccions nuclears, Nuclear Theory, Nuclear physics, Single pulse, Natural resources management, Reaction thresholds, Physics::Accelerator Physics, Física nuclear, Nuclear reactions, Nuclear Experiment
Abstract

The integral cross section of the12C(n, p)12B reaction was measured at the neutron time of flight facility nTOF at CERN, from the reaction threshold at 13.6 MeV up to 10 GeV, by means of the combined activation and a timeofflight technique. The integral result is expressed as the number of12B nuclei produced per single pulse of the neutron beam. A simple integral expression is given for calculating the number of produced12B nuclei from any given evaluated cross section and/or model prediction. © 2015, CERN. All rights reserved.

Published
2015

37. Mjerenje udarnoga presjeka za uhvat neutrona na izotopu 58Ni

Author

Žugec, Petar and Bosnar, Damir

Subjects
neutron background, Physics, udarni presjek za uhvat neutrona na 58Ni, GEANT4 simulacije, 58Ni neutron capture cross section, vrijeme proleta neutrona, NATURAL SCIENCES. Physics, n_TOF, neutron time of flight, GEANT4 simulations, PRIRODNE ZNANOSTI. Fizika, udc:53(043.3), Fizika, neutronska pozadina, Nuclear Experiment
Abstract

The (n, γ) cross section of 58Ni – of importance for the nuclear astrophysics, as well as for nuclear technologies – was measured at the neutron time-of-flight facility n_TOF at CERN. For the measurement, two C6D6 liquid scintillation detectors were used, specifically optimized to provide as low neutron sensitivity as possible. At n_TOF, the highly luminous white neutron beam covers 12 orders of magnitude in energy – from 10 meV to 10 GeV. It is produced by a pulsed beam of 20 GeV protons impinging on a massive Pb spallation target, yielding a total of 2 x 10^15 neutrons per pulse. Through an evacuated beamline the neutrons are transported towards the experimental area at a distance of approximately 185 m from a spallation target. In the process the beam is collimated by the set of two collimators, while charged particles are removed by a sweeping magnet. The neutron flux is actively monitored during the measurement by means of a silicon based neutron beam monitor SiMon, relying on 6Li(n, t)α reaction. The measurement is performed by detecting the prompt capture g-rays from 58Ni(n, γ) reaction. The kinetic energy of captured neutron is calculated from its time-of-flight, which is determined from a time-stamp of a detected γ-ray, relative to the start-signal caused by an intense γ-flash following every proton pulse hitting the spallation target. In order to calculate a capture yield from a measured data, the well-established Pulse HeightWeighting Technique was applied. A capture yield was analyzed in the energy range between 27 meV and 400 keV. The resolved resonance region was analyzed up to 122 keV by means of a multilevel R-matrix code SAMMY. Within the resolved resonance region 51 capture resonances were identified and their parameters reported. By complementing these results with the data from the unresolved resonance region – analyzed by the specialized code SESH – the Maxwellian averaged cross sections (MACS) were calculated for the stellar temperatures of kT = 5–100 keV. The new results call for the revaluation of the cross section data presently available throughout the various evaluation libraries, while revealing a significant impact on the final 58Ni abundance in the massive stars. In calculating the capture yield a significant effort has been paid to the clear identification of the separate background components. While the environmental and the so called empty-frame background are easily and regularly measured, the neutron background – caused by the neutrons elastically scattered off the sample itself – has been identified for the first time at n_TOF by means of the high-precision GEANT4 simulations. The simulated results were extensively compared against the available experimental data, confirming that they may be used with high degree of confidence for reaching the new precision standards in analyzing the capture data from n_TOF. Udarni presjek za uhvat neutrona na izotopu 58Ni – od važnosti za nuklearnu astrofiziku i tehnologije vezane uz nuklearnu fiziku – mjeren je na n_TOF postrojenju neutronskog vremena proleta u CERN-u. Kao mjerni instrumenti korištena su dva C6D6 tekuća scintilacijska detektora, posebno optimizirana kako bi osigurali najnižu izvedivu neutronsku osjetljivost. Intenzivan snop neutrona s n_TOF postrojenja proteže se 12 redova veličine u energiji – od 10 meV do 10 GeV. Snop se proizvodi izlaganjem masivne olovne spalacijske mete pulsnom protonskom snopu energije 20 GeV, pri čemu se oslobađa približno 2 x 10^15 neutrona po pulsu. Evakuirani cjevovod vodi snop prema eksperimentalnoj prostoriji udaljenoj približno 185 m od spalacijske mete. U međuvremenu snop se kolimira dvama kolimatorima i oslobađa nabijenih čestica snažnim magnetom. Tok neutrona aktivno se mjeri tijekom eksperimenta tzv. neutronskim monitorom snopa baziranim na siliciju, koji se oslanja na 6Li(n, t)α reakciju. Mjerenja neutronskih uhvata provode se detekcijom trenutno emitiranih g-zraka iz 58Ni(n, γ) reakcije. Kinetička energija uhvaćenog neutrona računa se iz njegova vremena proleta, koje se određuje iz vremena detekcije γ-zrake s obzirom na početni signal izazvan snažnim γ-bljeskom uzrokovanim udarom protonskoga snopa o spalacijsku metu. U svrhu izračuna vjerojatnosti uhvata iz eksperimentalnih podataka, pojedinim događajima pridruženi su odgovarajući težinski faktori na temelju visine mjerenih signala. Vjerojatnost uhvata analizirana je u energijskom rasponu od 27 meV do 400 keV. Područje raspoznatljivih rezonanci analizirano je do 122 keV primjenom programskoga koda SAMMY koji koristi formalizam R-matrice za obradu podataka. Unutar ovog područja izdvojena je i parametrizirana 51 rezonanca u udarnome presjeku za uhvat neutrona. Nadopunivši ove rezultate podacima iz područja neraspoznatljivih rezonanci – analiziranog posebnim programskim kodom SESH – izračunati su maxwellovski usrednjeni udarni presjeci za zvjezdane temperature od kT = 5–100 keV. Najnoviji rezultati ukazuju na potrebu za ponovljenim vrednovanjem udarnih presjeka dostupnih u različitim bazama podataka. Rezultati također pokazuju značajan utjecaj na zastupljenost konačnog sadržaja 58Ni u masivnim zvijezdama. Pri izračunu vjerojatnosti uhvata značajna pažnja posvećena je jasnoj identifikaciji izdvojenih doprinosa pozadinskim događajima. Pozadina uzrokovana prirodnim i induciranim zračenjem iz eksperimentalnog okruženja te pozadina uzrokovana prolaskom neutronskog snopa kroz eksperimentalnu prostoriju lako se i redovito mjere. No tzv. neutronska pozadina uzrokovana raspršenjem neutrona na samome mjerenom uzorku po prvi put u povijesti n_TOF postrojenja jasno je identificirana GEANT4 simulacijama visoke preciznosti. Simulirani rezultati uspoređeni su s dostupnim eksperimentalnim podacima, čime je potvrđeno da se s pouzdanošću mogu koristiti za postizanje nove razine preciznosti u analizi mjerenja neutronskih uhvata s n_TOF postrojenja.

Published
2014

38. Measurement of the 242Pu(n,f) cross section at the CERN n TOF facility

Author

F. Becvar, Srinivasan Ganesan, A. Tsinganis, Nicola Colonna, L.S. Leong, F. Mingrone, J. Andrzejewski, M. B. Gómez-Hornillos, S. Andriamonje, Jeri Kroll, E. Mendoza, C. Langer, Peter Schillebeeckx, N. Dzysiuk, Roberto Losito, A. Manousos, P. F. Mastinu, R. Sarmento, M. Mastromarco, A. Mallick, G. Vannini, A. Riego, A. Hernández-Prieto, Massimo Barbagallo, C. Carrapiço, Anton Wallner, F. Gunsing, J. Marganiec, P. Vaz, Cristian Massimi, W. Mondalaers, S. Altstadt, R. Versaci, A. Ventura, D. Bosnar, A. J. M. Plompen, G. Cortes, P. M. Milazzo, D. Tarrío, C. Lederer, F. Käppeler, M. Kokkoris, M. Mirea, C. Rubbia, M. S. Robles, K. Fraval, Variale, Vlachoudis, A. Pavlik, C. Domingo-Pardo, F. Calviño, N. Kivel, E. Jericha, H. Leeb, M. Sabaté-Gilarte, J. Perkowski, G. Giubrone, M Krtiˇcka, Dorothea Schumann, T. Martinez, Rene Reifarth, E. Berthoumieux, P. Gurusamy, J. L. Tain, D. Cano-Ott, M. Diakaki, Stefan Schmidt, A. K. Saxena, Arnaud Ferrari, G. Tagliente, D. G. Jenkins, J. M. Quesada, L. Tassan-Got, I. F. Gonçalves, C. Paradela, Alberto Mengoni, J. Billowes, L. Audouin, T. J. Wright, Mario Weigand, M. A. Cortés-Giraldo, Fabio Belloni, Bécares, C. Lampoudis, Boccone, S. Valenta, P. Zugec, Marco Calviani, E. Leal-Cidoncha, C. Eleftheriadis, Thomas Rauscher, D. Karadimos, E. González-Romero, M. P. W. Chin, Carlos Guerrero, F. Roman, M. Meaze, M. J. Vermeulen, A. R. García, M. Brugger, P. E. Koehler, Javier Praena, C. Weiss, R. Vlastou, T. Ware, E. Griesmayer, Y. Kadi, F. Cerutti, I. Duran, Rugard Dressler, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, Ventura, A., Mengoni, A., A. Tsingani, E. Berthoumieux, C. Guerrero, N. Colonna, M. Calviani, R. Vlastou, S. Andriamonje, V. Vlachoudi, F. Gunsing, C. Massimi, S. Altstadt, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, J. Billowe, V. Boccone, D. Bosnar, M. Brugger, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, M. Chin, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, C. Domingo-Pardo, I. Duran, R. Dressler, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, E. Griesmayer, P. Gurusamy, A. Hernandez-Prieto, D. G. Jenkin, E. Jericha, Y. Kadi, F. Kaeppeler, D. Karadimo, N. Kivel, P. Koehler, M. Kokkori, M. Krticka, J. Kroll, C. Lampoudi, C. Langer, E. Leal-Cidoncha, C. Lederer, H. Leeb, L. S. Leong, R. Losito, A. Mallick, A. Manouso, J. Marganiec, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Pavlik, J. Perkowski, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, R. Reifarth, A. Riego, M. S. Roble, F. Roman, C. Rubbia, M. Sabate-Gilarte, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, A. Wallner, T. Ware, M. Weigand, C. Wei, T. Wright, and P. Zugec

Subjects
Physics, Nuclear reaction, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Nuclear and High Energy Physics, Fission, Large Hadron Collider, Cross section, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, CERN - n_TOF, Nuclear Theory, TOF, Nuclear data, Neutron, NEUTRON TIME OF FLIGHT, Neutons, NEUTRON INDUCED FISSION, 242Pu, neutron induced fission, n_TOF, Nuclear physics, Cross section (physics), Nuclear reactions, Nuclear Experiment
Abstract

The accurate knowledge of relevant nuclear data is crucial for the design of advanced nuclear systems. These data include neutron cross sections of various plutonium isotopes and other minor actinides. The 242Pu(n,f) cross section was measured at the CERN n_TOF facility, taking advantage of the wide energy range (from thermal to GeV) and the high instantaneous flux of the neutron beam. Preliminary results for the measurement are presented., JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Published
2014

39. Fast neutron measurements at the nELBE time-of-flight facility

Author

Junghans, A. R., Beyer, R., Grosse, E., Hannaske, R., Kögler, T., Massarczyk, R., Schwengner, R., Wagner, A., Junghans, A. R., Beyer, R., Grosse, E., Hannaske, R., Kögler, T., Massarczyk, R., Schwengner, R., and Wagner, A.

Abstract

The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf has been rebuilt. A new enlarged experimental hall with a flight path of up to 10 m is available for neutron time-of-flight experiments in the fast energy range from about 50 keV to 10 MeV. nELBE is intended to deliver nuclear data of fast neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. The experimental programme consists of transmission measurements of neutron total cross sections, elastic and inelastic scattering cross section measurements, and neutron induced fission cross sections. The inelastic scattering to the first few excited states in 56Fe was investigated by measuring the gamma production cross section with an HPGe detector. The neutron induced fission of 242Pu was studied using fast ionisation chambers with large homogeneous actinide deposits.

Published
2015

40. Integral cross section measurement of the12C(n,p)12B reaction

Author

Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. NERG - Grup de Recerca d'Enginyeria Nuclear, Žugec, Petar, Colonna, Nicola, Bosnar, Damir, Ventura, A., Altstadt, Sebastian, Andrzejewski, Józef, Audouin, Ludmila, Barbagallo, Massimo, Bécares, Vicente, Berthoumieux, Eric, Brugger, Matthias, Calviani, Marco, Calviño Tavares, Francisco, Cano Ott, Daniel, Riego Pérez, Albert, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. NERG - Grup de Recerca d'Enginyeria Nuclear, Žugec, Petar, Colonna, Nicola, Bosnar, Damir, Ventura, A., Altstadt, Sebastian, Andrzejewski, Józef, Audouin, Ludmila, Barbagallo, Massimo, Bécares, Vicente, Berthoumieux, Eric, Brugger, Matthias, Calviani, Marco, Calviño Tavares, Francisco, Cano Ott, Daniel, and Riego Pérez, Albert

Abstract

The integral cross section of the12C(n, p)12B reaction was measured at the neutron time of flight facility nTOF at CERN, from the reaction threshold at 13.6 MeV up to 10 GeV, by means of the combined activation and a timeofflight technique. The integral result is expressed as the number of12B nuclei produced per single pulse of the neutron beam. A simple integral expression is given for calculating the number of produced12B nuclei from any given evaluated cross section and/or model prediction. © 2015, CERN. All rights reserved., Postprint (author's final draft)

Published
2015

41. Neutron-induced fission cross section of U-234 measured at the CERN n_TOF facility

Author

D. Karadimos, R. Vlastou, K. Ioannidis, P. Demetriou, M. Diakaki, V. Vlachoudis, P. Pavlopoulos, V. Konovalov, U. Abbondanno, G. Aerts, H. Alvarez, F. Alvarez Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulos, L. Audouin, G. Badurek, P. Baumann, F. Becvar, E. Berthoumieux, F. Calvino, D. Cano Ott, R. Capote, A. C. de, V. Chepel, E. Chiaveri, N. Colonna, G. Cortes, A. Couture, J. Cox, S. David, R. Dolfini, C. Domingo Pardo, A. Dorochenko, W. Dridi, I. Duran, C. Eleftheriadis, M. Embid Segura, L. Ferrant, A. Ferrari, R. Ferreira Marques, L. Fitzpatrick, H. Frais Koelbl, K. Fuji, W. Furman, I. Goncalves, R. Gallino, P. Cennini, E. Gonzalez Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, C. Guerrero, F. Gunsing, B. Haas, R. Haight, M. Heil, A. Herrera Martinez, M. Igashira, S. Isaev, E. Jericha, Y. Kadi, F. Kaeppeler, D. Karamanis, M. Kerveno, V. Ketlerov, P. Koehler, D. Kolokolov, M. Krticka, C. Lamboudis, H. Leeb, A. Lindote, I. Lopes, M. Lozano, S. Lukic, J. Marganiec, L. Marques, S. Marrone, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neves, H. Oberhummer, S. O'Brien, M. Oshima, J. Pancin, C. Papadopoulos, C. Paradela, N. Patronis, A. Pavlik, L. Perrot, R. Plag, A. Plompen, A. Plukis, A. Poch, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, M. Rosetti, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, L. Sarchiapone, I. Savvidis, M. Sedysheva, K. Stamoulis, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan Got, L. Tavora, R. Terlizzi, A. Tsinganis, P. Vaz, A. Ventura, D. Villamarin, M. C. Vincente, F. Voss, H. Wendler, M. Wiescher, K. Wisshak, MASSIMI, CRISTIAN, VANNINI, GIANNI, D. Karadimo, R. Vlastou, K. Ioannidi, P. Demetriou, M. Diakaki, V. Vlachoudi, P. Pavlopoulo, V. Konovalov, U. Abbondanno, G. Aert, H. Alvarez, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, L. Audouin, G. Badurek, P. Baumann, F. Becvar, E. Berthoumieux, F. Calvino, D. Cano-Ott, R. Capote, A. C. de, V. Chepel, E. Chiaveri, N. Colonna, G. Corte, A. Couture, J. Cox, S. David, R. Dolfini, C. Domingo-Pardo, A. Dorochenko, W. Dridi, I. Duran, C. Eleftheriadi, M. Embid-Segura, L. Ferrant, A. Ferrari, R. Ferreira-Marque, L. Fitzpatrick, H. Frais-Koelbl, K. Fuji, W. Furman, I. Goncalve, R. Gallino, P. Cennini, E. Gonzalez-Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, C. Guerrero, F. Gunsing, B. Haa, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, S. Isaev, E. Jericha, Y. Kadi, F. Kaeppeler, D. Karamani, M. Kerveno, V. Ketlerov, P. Koehler, D. Kolokolov, M. Krticka, C. Lamboudi, H. Leeb, A. Lindote, I. Lope, M. Lozano, S. Lukic, J. Marganiec, L. Marque, S. Marrone, C. Massimi, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neve, H. Oberhummer, S. O'Brien, M. Oshima, J. Pancin, C. Papadopoulo, C. Paradela, N. Patroni, A. Pavlik, L. Perrot, R. Plag, A. Plompen, A. Pluki, A. Poch, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, M. Rosetti, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, L. Sarchiapone, I. Savvidi, M. Sedysheva, K. Stamouli, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan-Got, L. Tavora, R. Terlizzi, A. Tsingani, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M. C. Vincente, F. Vo, H. Wendler, M. Wiescher, and K. Wisshak

Subjects
MINOR ACTINIDES TRANSMUTATIONS, Nuclear Experiment, NEUTRON TIME OF FLIGHT, NEUTRON INDUCED FISSION
Abstract

The neutron-induced fission cross section of U234 has been measured at the CERN n_TOF facility relative to the standard fission cross section of U235 from 20 keV to 1.4 MeV and of U238 from 1.4 to 200 MeV. A fast ionization chamber (FIC) was used as a fission fragment detector with a detection efficiency of no less than 97%. The high instantaneous flux and the low background characterizing the n_TOF facility resulted in wide-energy-range data (0.02 to 200 MeV), with high energy resolution, high statistics, and systematic uncertainties bellow 3%. Previous investigations around the energy of the fission threshold revealed structures attributed to β-vibrational levels, which have been confirmed by the present measurements. Theoretical calculations have been performed, employing the talys code with model parameters tuned to fairly reproduce the experimental data.

Published
2014

42. Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERN

Author

E. Mendoza, D. Cano Ott, C. Guerrero, E. Berthoumieux, U. Abbondanno, G. Aerts, F. Alvarez Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulos, L. Audouin, G. Badurek, J. Balibrea, P. Baumann, F. Becvar, F. Belloni, F. Calvino, M. Calviani, R. Capote, C. Carrapico, A. C. de, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Cortes, A. Couture, J. Cox, M. Dahlfors, S. David, I. Dillmann, R. Dolfini, C. Domingo Pardo, W. Dridi, I. Duran, C. Eleftheriadis, L. Ferrant, A. Ferrari, R. Ferreira Marques, L. Fitzpatrick, H. Frais Koelbl, K. Fujii, W. Furman, I. Goncalves, E. Gonzalez Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, F. Gunsing, B. Haas, R. Haight, M. Heil, A. Herrera Martinez, M. Igashira, S. Isaev, E. Jericha, F. Kaeppeler, Y. Kadi, D. Karadimos, D. Karamanis, V. Ketlerov, M. Kerveno, P. Koehler, V. Konovalov, E. Kossionides, M. Krticka, C. Lampoudis, H. Leeb, A. Lindote, S. L. Meo, I. Lopes, R. Lossito, M. Lozano, S. Lukic, J. Marganiec, L. Marques, S. Marrone, T. Martinez, MASSIMI, CRISTIAN, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neves, H. Oberhummer, S. O'Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulos, C. Paradela, N. Patronis, A. Pavlik, P. Pavlopoulos, L. Perrot, M. T. Pigni, R. Plag, A. Plompen, A. Plukis, A. Poch, J. Praena, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, C. Santos, L. Sarchiapone, I. Savvidis, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan Got, L. Tavora, R. Terlizzi, VANNINI, GIANNI, P. Vaz, A. Ventura, D. Villamarin, M. C. Vicente, V. Vlachoudis, R. Vlastou, F. Voss, S. Walter, H. Wendler, M. Wiescher, K. Wisshak, E. Mendoza, D. Cano-Ott, C. Guerrero, E. Berthoumieux, U. Abbondanno, G. Aert, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, L. Audouin, G. Badurek, J. Balibrea, P. Baumann, F. Becvar, F. Belloni, F. Calvino, M. Calviani, R. Capote, C. Carrapico, A. C. de, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Corte, A. Couture, J. Cox, M. Dahlfor, S. David, I. Dillmann, R. Dolfini, C. Domingo-Pardo, W. Dridi, I. Duran, C. Eleftheriadi, L. Ferrant, A. Ferrari, R. Ferreira-Marque, L. Fitzpatrick, H. Frais-Koelbl, K. Fujii, W. Furman, I. Goncalve, E. Gonzalez-Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, F. Gunsing, B. Haa, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, S. Isaev, E. Jericha, F. Kaeppeler, Y. Kadi, D. Karadimo, D. Karamani, V. Ketlerov, M. Kerveno, P. Koehler, V. Konovalov, E. Kossionide, M. Krticka, C. Lampoudi, H. Leeb, A. Lindote, S. L. Meo, I. Lope, R. Lossito, M. Lozano, S. Lukic, J. Marganiec, L. Marque, S. Marrone, T. Martinez, C. Massimi, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neve, H. Oberhummer, S. O'Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulo, C. Paradela, N. Patroni, A. Pavlik, P. Pavlopoulo, L. Perrot, M. T. Pigni, R. Plag, A. Plompen, A. Pluki, A. Poch, J. Praena, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, C. Santo, L. Sarchiapone, I. Savvidi, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan-Got, L. Tavora, R. Terlizzi, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M. C. Vicente, V. Vlachoudi, R. Vlastou, F. Vo, S. Walter, H. Wendler, M. Wiescher, and K. Wisshak

Subjects
RADIATIVE NEUTRON CAPTURE, NEUTRON TIME OF FLIGHT
Abstract

Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am243(n,γ) cross section uncertainty. Method: The Am243(n,γ) cross section has been measured at the n-TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am243(n,γ) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am243(n,γ) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries. Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am243(n,γ) cross section uncertainty. Method: The Am243(n,γ) cross section has been measured at the n-TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am243(n,γ) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am243(n,γ) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries.

Published
2014

43. Measurement and analysis of the Am-241(n,gamma) cross section with liquid scintillator detectors using time-of-flight spectroscopy at the n_TOF facility at CERN

Author

K. Fraval, F. Gunsing, S. Altstadt, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becares, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowes, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, N. Colonna, G. Cortes, M. A. Cortes Giraldo, M. Diakaki, C. Domingo Pardo, I. Duran, R. Dressler, N. Dzysiuk, C. Eleftheriadis, A. Ferrari, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez Hornillos, I. F. Goncalves, E. Gonzalez Romero, E. Griesmayer, C. Guerrero, P. Gurusamy, A. Hernandez Prieto, D. G. Jenkins, E. Jericha, Y. Kadi, F. Kappeler, D. Karadimos, N. Kivel, P. Koehler, M. Kokkoris, M. Krticka, J. Kroll, C. Lampoudis, C. Langer, E. Leal Cidoncha, C. Lederer, H. Leeb, L. S. Leong, R. Losito, A. Mallick, A. Manousos, J. Marganiec, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, M. Mirea, W. Mondalaers, C. Paradela, A. Pavlik, J. Perkowski, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, R. Reifarth, A. Riego, M. S. Robles, F. Roman, C. Rubbia, M. Sabate Gilarte, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan Got, A. Tsinganis, S. Valenta, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudis, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Weiss, T. Wright, P. Zugec, MASSIMI, CRISTIAN, MINGRONE, FEDERICA, VANNINI, GIANNI, K. Fraval, F. Gunsing, S. Altstadt, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, N. Colonna, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, C. Domingo-Pardo, I. Duran, R. Dressler, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, E. Griesmayer, C. Guerrero, P. Gurusamy, A. Hernandez-Prieto, D. G. Jenkin, E. Jericha, Y. Kadi, F. Kappeler, D. Karadimo, N. Kivel, P. Koehler, M. Kokkori, M. Krticka, J. Kroll, C. Lampoudi, C. Langer, E. Leal-Cidoncha, C. Lederer, H. Leeb, L. S. Leong, R. Losito, A. Mallick, A. Manouso, J. Marganiec, T. Martinez, C. Massimi, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Pavlik, J. Perkowski, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, R. Reifarth, A. Riego, M. S. Roble, F. Roman, C. Rubbia, M. Sabate-Gilarte, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudi, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Wei, T. Wright, and P. Zugec

Subjects
radiative capture cross section, NEUTRON TIME OF FLIGHT
Abstract

The Am241(n,γ) cross section has been measured at the n_TOF facility at CERN using deuterated benzene liquid scintillators, commonly known as C6D6 detectors, and time-of-flight spectrometry. The results in the resolved resonance range bring new constraints to evaluations below 150 eV, and the energy upper limit was extended from 150 to 320 eV with a total of 172 new resonances not present in current evaluations. The thermal capture cross section was found to be σth=678±68 b, which is in good agreement with evaluations and most previous measurements. The capture cross section in the unresolved resonance region was extracted in the remaining energy range up to 150 keV, and found to be larger than current evaluations and previous measurements.

Published
2014

44. Neutron Capture Reactions on Fe and Ni Isotopes for the Astrophysical s-process

Author

A. R. García, M. Brugger, C. Eleftheriadis, Thomas Rauscher, D. Karadimos, E. González-Romero, M. P. W. Chin, T. Ware, F. Roman, E. Griesmayer, E. Chiaveri, J. L. Tain, P. F. Mastinu, Marco Pignatari, S. Valenta, G. Giubrone, J. Billowes, G. Tagliente, Mario Weigand, Marco Calviani, Srinivasan Ganesan, F. Käppeler, M. B. Gómez-Hornillos, P. E. Koehler, E. Jericha, P. Vaz, C. Lederer, M. Mirea, Mario Barbagallo, D. Cano-Ott, Dorothea Schumann, S. Altstadt, M. Diakaki, Jeri Kroll, C. Weiß, A. Pavlik, C. Domingo-Pardo, N. Kivel, F. Bečvář, H. Leeb, Alberto Mengoni, Javier Praena, R. Sarmento, A. Manousos, A. J. M. Plompen, E. Mendoza, Arnaud Ferrari, A. Riego, M. Meaze, Peter Schillebeeckx, M. J. Vermeulen, M. A. Cortés-Giraldo, N. Dzysiuk, J. Perkowski, J. Marganiec, P. Gurusamy, K. Fraval, Carlos Guerrero, I. Duran, P. M. Milazzo, C. Rubbia, M. Krtička, F. Calviño, I. F. Gonçalves, F. Cerutti, V. Bécares, R. Vlastou, F. Gunsing, T. Martinez, M. Mastromarco, M. Kokkoris, Damir Bosnar, Y. Kadi, G. Cortes, C. Carrapiço, Anton Wallner, Cristian Massimi, D. Tarrío, Fabio Belloni, D. G. Jenkins, E. Berthoumieux, G. Vannini, Petar Žugec, W. Mondelaers, V. Variale, Roberto Versaci, F. Mingrone, J. Andrzejewski, T. J. Wright, C. Langer, Roberto Losito, Rugard Dressler, A. Tsinganis, Nicola Colonna, L.S. Leong, Vasilis Vlachoudis, A. Ventura, Gunther Korschinek, C. Paradela, Rene Reifarth, Stefan Schmidt, L. Audouin, Vittorio Boccone, J. M. Quesada, L. Tassan-Got, Ventura, A., Mengoni, A., Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, C. Lederer, G. Giubrone, C. Massimi, P. Zugec, M. Barbagallo, N. Colonna, C. Domingo-Pardo, C. Guerrero, F. Gunsing, F. Kaeppeler, J. L. Tain, S. Altstadt, J. Andrzejewski, L. Audouin, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, I. Duran, R. Dressler, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, E. Griesmayer, P. Gurusamy, D. G. Jenkin, E. Jericha, Y. Kadi, D. Karadimo, N. Kivel, P. Koehler, M. Kokkori, G. Korschinek, M. Krticka, J. Kroll, C. Langer, H. Leeb, L. S. Leong, R. Losito, A. Manouso, J. Marganiec, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondelaer, C. Paradela, A. Pavlik, J. Perkowski, M. Pignatari, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, R. Reifarth, A. Riego, F. Roman, C. Rubbia, R. Sarmento, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudi, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Wei, T. J. Wright, and 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)

Subjects
Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, RADIATIVE NEUTRON CAPTURE, Nuclear Theory, Neutron, Neutron scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Nuclear physics, neutron capture, n_TOF, s-process, Neutron cross section, Nuclear Experiment, capture, Physics, Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Cross section, TOF, NEUTRON TIME OF FLIGHT, Neutron temperature, Neutron capture, Neutron source, r-process, S PROCESS, Nuclear reactions, Nucleosynthesis
Abstract

See paper for full list of authors; Neutron capture cross sections in the keV neutron energy region are the key nuclear physics input to study the astrophysical slow neutron capture process. In the past years, a series of neutron capture cross section measurements has been performed at the neutron time-of-flight facility n_TOF at CERN focussing on the Fe/Ni mass region. Recent results and future developments in the neutron time-of-flight technique are discussed.

Published
2014
Full Text
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45. Experimental neutron capture data of 58Ni from the CERN n_TOF facility

Author

TOF Collaboration, ��ugec, P., Barbagallo, M., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., B��cares, V., Be��v����, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calvi��o, F., Cano-Ott, D., Carrapi��o, C., Cerutti, F., Chiaveri, E., Chin, M., Cort��s, G., Cort��s-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Duran, I., Dzysiuk, N., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., Garc��a, A. R., Giubrone, G., G��mez-Hornillos, M. B., Gon��alves, I. F., Gonz��lez-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Jenkins, D. G., Jericha, E., Kadi, Y., K��ppeler, F., Karadimos, D., Koehler, P., Kokkoris, M., Krti��ka, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., Losito, R., Manousos, A., Marganiec, J., Mart��nez, 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., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Schillebeeckx, P., Schmidt, S., Tagliente, G., Tain, J. L., Tarr��o, 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., Wei��, C., Wright, T., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, nTOF, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, National Science Foundation (NSF). United States, Joint Institute for Nuclear Astrophysics (JINA) U.S., Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, Ventura, A., Mengoni, A., P. Zugec, M. Barbagallo, N. Colonna, D. Bosnar, S. Altstadt, J. Andrzejewski, L. Audouin, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, C. Domingo-Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, E. Griesmayer, C. Guerrero, F. Gunsing, P. Gurusamy, D. G. Jenkin, E. Jericha, Y. Kadi, F. Kaeppeler, D. Karadimo, P. Koehler, M. Kokkori, M. Krticka, J. Kroll, C. Langer, C. Lederer, H. Leeb, L. S. Leong, R. Losito, A. Manouso, J. Marganiec, T. Martinez, C. Massimi, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Pavlik, J. Perkowski, M. Pignatari, A. Plompen, J. Praena, J. M. Quesada, T. Rauscher, R. Reifarth, A. Riego, F. Roman, C. Rubbia, R. Sarmento, P. Schillebeeckx, S. Schmidt, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudi, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Wei, T. Wright, and 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)

Subjects
Nuclear and High Energy Physics, nTOF, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, NEUTRON RESONANCE ANALYSIS, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Time of flight, 58Ni neutron capture cross section, n_TOF, MACS, 0103 physical sciences, Neutron cross section, Física::Electromagnetisme [Àrees temàtiques de la UPC], Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Neutrons, Large Hadron Collider, Cross section, 010308 nuclear & particles physics, CERN - n_TOF, Resonance, Física, NEUTRON TIME OF FLIGHT, Neutron temperature, Neutron capture, Neutrons Capture, S PROCESS, s-process
Abstract

The $^{58}$Ni $(n,\gamma)$ cross section has been measured at the neutron time of flight facility n_TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT$=$5-100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2$\pm$0.6$_\mathrm{stat}\pm$1.8$_\mathrm{sys}$ mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When included in models of the s-process nucleosynthesis in massive stars, this change results in a 60% increase of the abundance of $^{58}$Ni, with a negligible propagation on heavier isotopes. The reason is that, using both the old or the new MACS, 58Ni is efficiently depleted by neutron captures., Comment: 10 pages, 8 figures, 5 tables

Published
2014
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46. The (n,alpha) Reaction in the s-process Branching Point Ni-59

Author

C. Weiss, C. Guerrero, E. Griesmayer, J. Andrzejewski, G. Badurek, E. Chiaveri, R. Dressler, S. Ganesan, E. Jericha, F. Kaeppeler, P. Koehler, C. Lederer, H. Leeb, J. Marganiec, A. Pavlik, J. Perkowski, T. Rauscher, R. Reifarth, D. Schumann, G. Tagliente, V. Vlachoudis, S. Altstadt, L. Audouin, M. Barbagallo, V. Becares, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowes, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano Ott, C. Carrapico, F. Cerutti, M. Chin, N. Colonna, G. Cortes, M. A. Cortes Giraldo, M. Diakaki, C. Domingo Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadis, A. Ferrari, K. Fraval, A. R. Garcia, G. Giubrone, M. B. Gomez Hornillos, I. F. Goncalves, E. Gonzalez Romero, F. Gunsing, P. Gurusamy, A. Hernandez Prieto, D. G. Jenkins, Y. Kadi, D. Karadimos, N. Kivel, M. Kokkoris, M. Krticka, J. Kroll, C. Lampoudis, C. Langer, E. Leal Cidoncha, L. S. Leong, R. Losito, A. M. Llick, A. Manousos, T. Martinez, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, M. Mirea, W. Mondalaers, C. Paradela, A. Plompen, J. Praena, J. M. Quesada, A. Riego, M. S. Robles, F. Roman, C. Rubbia, M. Sabate Gilarte, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, J. L. Tain, D. Tarrio, L. Tassan Got, A. Tsinganis, S. Valenta, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, R. Vlastou, A. Wallner, T. Ware, M. Weigand, T. Wright, P. Zugec, MASSIMI, CRISTIAN, MINGRONE, FEDERICA, VANNINI, GIANNI, C. Wei, C. Guerrero, E. Griesmayer, J. Andrzejewski, G. Badurek, E. Chiaveri, R. Dressler, S. Ganesan, E. Jericha, F. Kaeppeler, P. Koehler, C. Lederer, H. Leeb, J. Marganiec, A. Pavlik, J. Perkowski, T. Rauscher, R. Reifarth, D. Schumann, G. Tagliente, V. Vlachoudi, S. Altstadt, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, D. Bosnar, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, M. Chin, N. Colonna, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, C. Domingo-Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, K. Fraval, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, F. Gunsing, P. Gurusamy, A. Hernandez-Prieto, D. G. Jenkin, Y. Kadi, D. Karadimo, N. Kivel, M. Kokkori, M. Krticka, J. Kroll, C. Lampoudi, C. Langer, E. Leal-Cidoncha, L. S. Leong, R. Losito, A. M. Llick, A. Manouso, T. Martinez, C. Massimi, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Plompen, J. Praena, J. M. Quesada, A. Riego, M. S. Roble, F. Roman, C. Rubbia, M. Sabate-Gilarte, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, R. Vlastou, A. Wallner, T. Ware, M. Weigand, T. Wright, and P. Zugec

Subjects
(n, a) reaction cross section, diamond detector, NEUTRON TIME OF FLIGHT
Abstract

The (n, α) reaction in the radioactive 59Ni is of relevance in nuclear astrophysics as 59Ni can be considered as the first branching point in the astrophysical s-process. Its relevance in nuclear technology is especially related to material embrittlement in stainless steel. However, there is a discrepancy between available experimental data and the evaluated nuclear data files for this reaction. At the n_TOF facility at CERN, a dedicated system based on sCVD diamond diodes was set up to measure the 59Ni(n, α)56Fe cross section. The results of this measurement, with special emphasis on the dominant resonance at 203 eV, are presented here.

Published
2014

47. Measurement of the C-12(n, p)B-12 cross section at n_TOF at CERN by in-beam activation analysis

Author

Zugec, P., Colonna, N., Bosnar, D., Mengoni, A., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Becares, V., Becvar, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calvino, F., Cano Ott, D., Carrapico, C., Cerutti, F., Chiaveri, E., Chin, M., Cortes, G., Cortes Giraldo, M. A., Cosentino, L., Diakaki, M., Domingo Pardo, C., Dressler, R., Duran, I., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., Garcia, A. R., Giubrone, G., Gomez Hornillos, M. B., Goncalves, I. F., Gonzalez Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D. G., Jericha, E., Kaeppeler, F., Karadimos, D., Kivel, N., Kokkoris, M., Krticka, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., Lo Meo, S., Losito, R., Manousos, A., Marganiec, J., Martinez, T., Massimi, C., Mastinu, P., Mastromarco, M., Mendoza, E., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Musumarra, Agatino, Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrio, 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., Wright, T., P. Zugec, N. Colonna, D. Bosnar, A. Mengoni, S. Altstadt, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapico, F. Cerutti, E. Chiaveri, M. Chin, G. Corte, M. A. Cortes-Giraldo, L. Cosentino, M. Diakaki, C. Domingo-Pardo, R. Dressler, I. Duran, C. Eleftheriadi, A. Ferrari, P. Finocchiaro, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Goncalve, E. Gonzalez-Romero, E. Griesmayer, C. Guerrero, F. Gunsing, P. Gurusamy, S. Heinitz, D. G. Jenkin, E. Jericha, F. Kaeppeler, D. Karadimo, N. Kivel, M. Kokkori, M. Krticka, J. Kroll, C. Langer, C. Lederer, H. Leeb, L. S. Leong, S. L. Meo, R. Losito, A. Manouso, J. Marganiec, T. Martinez, C. Massimi, P. Mastinu, M. Mastromarco, E. Mendoza, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, A. Musumarra, C. Paradela, A. Pavlik, J. Perkowski, A. Plompen, J. Praena, J. Quesada, T. Rauscher, R. Reifarth, A. Riego, F. Roman, C. Rubbia, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudi, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Wei, and T. Wright

Subjects
integral cross section, Nuclear Experiment, NEUTRON TIME OF FLIGHT
Abstract

The integral cross section of the C-12(n, p)B-12 reaction has been determined for the first time in the neutron energy range from threshold to several GeV at the n_TOF facility at CERN. The measurement relies on the activation technique with the beta decay of B-12 measured over a period of four half-lives within the same neutron bunch in which the reaction occurs. The results indicate that model predictions, used in a variety of applications, are mostly inadequate. The value of the integral cross section reported here can be used as a benchmark for verifying or tuning model calculations.

Published
2014

48. GEANT4 simulation of the neutron background of the C6D6 set-up for capture studies at n_TOF

Author

collaboration, n_TOF, Žugec, P., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., 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., Meo, S. Lo, Losito, R., Manousos, A., Marganiec, J., Martìnez, 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., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, 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., Wright, T., Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, P. Zugec, N. Colonna, D. Bosnar, S. Altstadt, J. Andrzejewski, L. Audouin, M. Barbagallo, V. Becare, F. Becvar, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, M. Brugger, M. Calviani, F. Calvino, D. Cano-Ott, C. Carrapio, F. Cerutti, E. Chiaveri, M. Chin, G. Corte, M. A. Cortes-Giraldo, M. Diakaki, C. Domingo-Pardo, R. Dressler, I. Duran, N. Dzysiuk, C. Eleftheriadi, A. Ferrari, K. Fraval, S. Ganesan, A. R. Garcia, G. Giubrone, M. B. Gomez-Hornillo, I. F. Gonalve, E. Gonzalez-Romero, E. Griesmayer, C. Guerrero, F. Gunsing, P. Gurusamy, S. Heinitz, D. G. Jenkin, E. Jericha, Y. Kadi, F. Kaeppler, D. Karadimo, N. Kivel, P. Koehler, M. Kokkori, M. Krticka, J. Kroll, C. Langer, C. Lederer, H. Leeb, L. S. Leong, S. Lomeo, R. Losito, A. Manouso, J. Marganiec, T. Mart-Nez, C. Massimi, P. F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Mingrone, M. Mirea, W. Mondalaer, C. Paradela, A. Pavlik, J. Perkowski, A. Plompen, J. Praenam, J. M. Quesadam, T. Rauscher, R. Reifarth, A. Riego, F. Roman, C. Rubbia, R. Sarmento, A. Saxena, P. Schillebeeckx, S. Schmidt, D. Schumann, G. Tagliente, J. L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, R. Versaci, M. J. Vermeulen, V. Vlachoudi, R. Vlastou, A. Wallner, T. Ware, M. Weigand, C. Wei, T. Wright, Ventura, A., Mengoni, A., Lo Meo, S., and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear

Subjects
Neutron capture, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, GEANT4 simulations, Neutron time of flight, Neutron background, n_TOF, FOS: Physical sciences, Neutron, N-TOF, 7. Clean energy, 01 natural sciences, Partícules (Física nuclear), Nuclear physics, Cross section (physics), 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, physics.ins-det, GEANT4, Line (formation), Particles (Nuclear physics), Physics, Bonner sphere, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, GEANT4 simulation, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, Detector, Física, Neutron sensitivity, Instrumentation and Detectors (physics.ins-det), Neutron radiation, NEUTRON TIME OF FLIGHT, Background, Deuterium, N_TOF, Simulation
Abstract

The neutron sensitivity of the C6D6 detector setup used at n_TOF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has beeni mplemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with anatC sample, showing an excellent agreement above 1 keV. At lower energies, an additional component in the measured natC yield has been discovered, which prevents the use of natC data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron background for two different samples are demonstrating the important role of accurate simulations of the neutron background in capture cross-section measurements., JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Published
2014

49. Present status and future programs of the n_TOF experiment

Author

S. Valenta, Marco Calviani, F. Cerutti, M. P. W. Chin, M. Krtička, F. Calviño, F. Roman, Srinivasan Ganesan, T. Martinez, F. Gramegna, M. B. Gómez-Hornillos, Alberto Mengoni, F. Beĉvář, M. Fernandez-Ordonez, Manuel Lozano, A. Manousos, Javier Praena, J. Marganiec, S. Andriamonje, R. Versaci, Mario Barbagallo, M. Brugger, C. Carrapiço, A. Riego, Matthias Heil, G. Tagliente, G. Cortes, E. Chiaveri, M. A. Cortés-Giraldo, P. F. Mastinu, R. Vlastou, M. Kokkoris, J. Andrzejewski, M. Mirea, C. Eleftheriadis, J. Billowes, D. Tarrío, Jeri Kroll, I. Duran, Thomas Rauscher, Carlo Rubbia, C. Lederer, R. Sarmento, D. Karadimos, M. Mastromarco, E. González-Romero, Carlos Guerrero, F. Avrigeanu, V. Variale, H. Leeb, M. Meaze, V. Vlachoudis, I. F. Gonçalves, D. Cano-Ott, J. L. Tain, Anton Wallner, P. Vaz, M. J. Vermeulen, M. Diakaki, Rene Reifarth, J. Perkowski, T. J. Wright, Fabio Belloni, T. Ware, F. Käppeler, Alberto Ventura, Yacine Kadi, K. Fraval, F. Gunsing, E. Griesmayer, D. G. Jenkins, E. Berthoumieux, J. M. Quesada, Cristian Massimi, A. Pavlik, L. Tassan-Got, C. Domingo-Pardo, C. Paradela, V. Boccone, L. Audouin, G. Vannini, Iris Dillmann, G. Giubrone, Roberto Losito, A. Tsinganis, Nicola Colonna, L.S. Leong, V. Bécares, E. Jericha, C. Weiß, E. Mendoza, P. M. Milazzo, N. Dzysiuk, Alfredo Ferrari, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, E. Chiaveri, M. Calviani, V. Vlachoudi, C. Wei, S. Andriamonje, J. Andrzejewski, L. Audouin, F. Avrigeanu, M. Barbagallo, V. Bécare, F. Beĉvář, F. Belloni, E. Berthoumieux, J. Billowe, V. Boccone, M. Brugger, F. Calviño, D. Cano-Ott, C. Carrapiço, F. Cerutti, M. Chin, N. Colonna, G. Corté, M.A. Cortés-Giraldo, M. Diakaki, I. Dillmann, C. Domingo-Pardo, I. Duran, N. Dzysiuk, C. Eleftheriadi, M. Fernández-Ordóñez, A. Ferrari, K. Fraval, S. Ganesan, G. Giubrone, M.B. Gómez-Hornillo, I.F. Gonçalve, E. González-Romero, F. Gramegna, E. Griesmayer, C. Guerrero, F. Gunsing, M. Heil, D.G. Jenkin, E. Jericha, Y. Kadi, F. Käppeler, D. Karadimo, M. Kokkori, M. Krtička, J. Kroll, C. Lederer, H. Leeb, L.S. Leong, R. Losito, M. Lozano, A. Manouso, J. Marganiec, T. Martinez, C. Massimi, P.F. Mastinu, M. Mastromarco, M. Meaze, E. Mendoza, A. Mengoni, P.M. Milazzo, M. Mirea, C. Paradela, A. Pavlik, J. Perkowski, J. Praena, J.M. Quesada, T. Rauscher, R. Reifarth, A. Riego, F. Roman, C. Rubbia, R. Sarmento, G. Tagliente, J.L. Tain, D. Tarrio, L. Tassan-Got, A. Tsingani, S. Valenta, G. Vannini, V. Variale, P. Vaz, A. Ventura, M.J. Vermeulen, R. Versaci, R. Vlastou, A. Wallner, T. Ware, and T.J. Wright

Subjects
Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Physics, Astrofísica nuclear, Information retrieval, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, CERN - n_TOF, Nuclear Theory, Creative commons, NEUTRON TIME OF FLIGHT, Nuclear physics, Física::Astronomia i astrofísica [Àrees temàtiques de la UPC], Physics::Accelerator Physics, Nuclear astrophysics, Nuclear Experiment, License
Abstract

The neutron time-of-flight facility n_TOF at CERN, Switzerland, operational since 2001, delivers neutrons using the Proton Synchrotron (PS) 20 GeV/c proton beam impinging on a lead spallation target. The facility combines a very high instantaneous neutron flux, an excellent time of flight resolution due to the distance between the experimental area and the production target (185 meters), a low intrinsic background and a wide range of neutron energies, from thermal to GeV neutrons. These characteristics provide a unique possibility to perform neutron-induced capture and fission cross-section measurements for applications in nuclear astrophysics and in nuclear reactor technology. The most relevant measurements performed up to now and foreseen for the future will be presented in this contribution. The overall efficiency of the experimental program and the range of possible measurements achievable with the construction of a second experimental area (EAR-2), vertically located 20 m on top of the n_TOF spallation target, might offer a substantial improvement in measurement sensitivities. A feasibility study of the possible realisation of the installation extension will be also presented.

Published
2012

50. Ce3Pt23Si11 ferromagnet: unusual magnetic behavior brought to light by neutron studies

Author

Opagiste, Christine, Galéra, Rose-Marie, Amara, Mehdi, Paulsen, Carley, Rols, S., Ouladdiaf, B., and Opagiste, Christine

Subjects
cerium compound, neutron diffraction, Condensed Matter::Superconductivity, Ce3Pt23Si11, [PHYS.COND.CM-SCE] Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], neutron time of flight, ferromagnetism
Abstract

The ternary system R-Pt-Si (R = rare earth element) triggers a lot of interest, due to peculiar physical behaviors of some compounds: unconventional superconductivity, heavy-fermion properties, coexistence of superconductivity and magnetic ordering..., such as CePt3Si, reported as the first non-centro symmetric heavy fermion superconductor. Actually, several studies let suppose a sample dependence of the superconductivity and for instance, in Ce deficient samples, the coexistence of a new phase, Ce3Pt23Si11, was suspected to interfere with superconducting properties. We have undertaken an extended investigation on this new phase.

Published
2011

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