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Start Over Author "Diakaki, M." Topic monte carlo method
7 results on '"Diakaki, M."'

1. Cross section of the 197Au(n,2n)196Au reaction.

Author

Kalamara, A., Vlastou, R., Kokkoris, M., Diakaki, M., Serris, M., Patronis, N., Axiotis, M., and Lagoyannis, A.

Subjects
NEUTRON cross sections, NUCLEAR reactions, NUCLEAR energy, NEUTRON temperature, MONTE Carlo method
Abstract

The 197Au(n,2n)196Au reaction cross section has been measured at two energies, namely at 17.1MeV and 20.9MeV, by means of the activation technique, relative to the 27Al(n,α)24Na reference reaction cross section. Quasi-monoenergetic neutron beams were produced at the 5.5MV Tandem T11/25 accelerator laboratory of NCSR "Demokritos", by means of the ³H(d,n)4He reaction, implementing a new Ti-tritiated target of ~400 GBq activity. The induced ? -ray activity at the targets and reference foils has been measured with HPGe detectors. The cross section for the population of the second isomeric (12-) state m2 of 196Au was independently determined. Auxiliary Monte Carlo simulations were performed using the MCNP code. The present results are in agreement with previous experimental data and with theoretical calculations of the measured reaction cross sections, which were carried out with the use of the EMPIRE code. [ABSTRACT FROM AUTHOR]

Published
2017
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2. Measurement of the U(n, f ) cross-section with quasi-monoenergetic beams in the keV and MeV range using a Micromegas detector assembly.

Author

Stamatopoulos, A., Kanellakopoulos, A., Kalamara, A., Diakaki, M., Tsinganis, A., Kokkoris, M., Michalopoulou, V., Axiotis, M., Lagoyiannis, A., and Vlastou, R.

Subjects
URANIUM, MONOENERGETIC radiation, NEUTRON temperature, NEUTRON scattering, MONTE Carlo method, NUCLEAR fission
Abstract

The U neutron-induced fission cross-section has been measured at incident neutron energies of 452, 550, 651 keV and 7.5, 8.7, 10 MeV using the Li ( p, n) and the H( d, n) reactions, respectively, relative to the U( n, f ) and U( n, f ) reference reactions. The measurement was performed at the neutron beam facility of the National Center for Scientific Research 'Demokritos', using a set-up based on Micromegas detectors. The active mass of the actinide samples and the corresponding impurities were determined via $ \alpha$ -spectroscopy using a surface barrier silicon detector. The neutron spectra intercepted by the actinide samples have been thoroughly studied by coupling the NeuSDesc and MCNP5 codes, taking into account the energy and angular straggling of the primary ion beams in the neutron source targets in addition to contributions from competing reactions ( e.g. deuteron break-up) and neutron scattering in the surrounding materials. Auxiliary Monte Carlo simulations were performed making combined use of the FLUKA and GEF codes, focusing particularly on the determination of the fission fragment detection efficiency. The developed methodology and the final results are presented. [ABSTRACT FROM AUTHOR]

Published
2018
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3. Isomeric cross section of the 197Au(n,2n) reaction.

Author

Tsinganis, A., Diakaki, M., Kokkoris, M., Lagoyannis, A., Mara, E., Papadopoulos, C. T., and Vlastou, R.

Subjects
*NUCLEAR reactions, *NEUTRONS, *NUCLEAR activation analysis, *MONTE Carlo method, *DEUTERIUM, *NEUTRON flux
Abstract

In the present work, the 197Au(n,2n) reaction cross section is experimentally determined relative to the 27Al(n,α)24Na reaction at incident neutron energies of 9.0-10.5 MeV by means of the activation technique. The quasimonoenergetic fast neutron beam was produced via the 2H(d,n)3He reaction at the 5.5-MV Tandem Van de Graaff accelerator at the National Centre of Scientific Research (NCSR) "Demokritos" and was studied to determine the contribution of background "parasitic" neutrons using the multiple foil activation technique and the SULSA unfolding code. The cross sections for the population of the second isomeric state (12-) of 196Au and the sum of the ground (2-) and first isomeric state (5-) population cross sections were independently determined. Auxiliary Monte Carlo simulations were performed with the MCNP code. Theoretical calculations of the above cross sections in the 8-25 MeV region were carried out with the use of the STAPRE-F, EMPIRE, and TALYS codes, which were also compared in their implementation of the generalized superfluid model. The theoretical results are compared with previous work in the same mass region, and the strong dependence on the level scheme of the nuclei involved was revealed. [ABSTRACT FROM AUTHOR]

Published
2011
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4. Characterization of the neutron flux distribution at the Athens Tandem Accelerator NCSR “Demokritos”

Author

Vlastou, R., Kokkoris, M., Diakaki, M., Constantinou, Ch., Kalfas, C.A., Kotrotsou, A., Lagoyannis, A., Lambrou, M., Loizou, V., Mara, E., Paneta, V., Provatas, G., and Tsinganis, A.

Subjects
*NEUTRON flux, *PARTICLE accelerators, *NEUTRON beams, *ENERGY security, *LIQUID scintillators, *MONTE Carlo method
Abstract

Abstract: Quasi-monoenergetic neutron beams, in the energy range 7–11.5MeV, produced via the 2H(d,n) reaction, have been used at the 5.5MV tandem T11/25 Accelerator Laboratory of NCSR “Demokritos”. The flux variation of the neutron beam is monitored with a BF3 detector, while the absolute flux is obtained with respect to reference reactions. An investigation of the energy dependence of the neutron fluence has been carried out using two independent techniques: by a liquid scintillator BC501A detector and deconvolution of its recoil energy spectra performed by means of the DIFBAS code, as well as via the multiple foil activation technique in combination with the SULSA unfolding code. The neutron facility has also been characterized by means of Monte Carlo simulations with MCNP5. [Copyright &y& Elsevier]

Published
2011
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5. Matter radii of 32-35Mg.

Author

Kanungo, R., Prochazka, A., Horiuchi, W., Nociforo, C., Aumann, T., Boutin, D., Cortina-Gil, D., Davids, B., Diakaki, M., Farinon, F., Geissel, H., Gernhäuser, R., Gerl, J., Janik, R., Jonson, B., Kindler, B., Knöbel, R., Krucken, R., Lantz, M., and Lenske, H.

Subjects
*MATTER, *NEUTRONS, *PARTICLES (Nuclear physics), *COULOMB excitation, *MEAN field theory, *MONTE Carlo method
Abstract

The interaction cross sections of 32-35Mg at 900A MeV have been measurmed using the fragment separator at GSI. The deviation from the r0A1/3 trend is slightly larger for 35Mg, signaling the possible formation of a longer tail in the neutron distribution for 35Mg. The radii extracted from a Glauber model analysis with Fermi densities are consistent with models predicting the development of neutron skins. [ABSTRACT FROM AUTHOR]

Published
2011
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6. Monte carlo simulations of the n_TOF lead spallation target with the Geant4 toolkit: A benchmark study

Author

S. Warren, J. Andrzejewski, V. Variale, M. Mastromarco, Pedro G. Ferreira, G. Vannini, M. A. Cortés-Giraldo, Rugard Dressler, N. Patronis, A. K. Saxena, Arnaud Ferrari, J. Billowes, J. Marganiec, E. Jericha, Paolo Finocchiaro, Anton Wallner, M. Caamaño, Nicola Colonna, A. Musumarra, Dorothea Schumann, E. Chiaveri, P. F. Mastinu, J. Balibrea, J. A. Ryan, Vasilis Vlachoudis, C. Rubbia, A. Tarifeño-Saldivia, G. Cortes, E. González, A. Pavlik, L. Audouin, A. Ventura, M. Sabaté-Gilarte, F. Calviño, H. Leeb, J. Perkowski, A. Casanovas, Y. H. Chen, P. C. Rout, C. Domingo-Pardo, M. Bacak, A. Kimura, J. L. Tain, F. Gunsing, T. Glodariu, F. Mingrone, A. Masi, D. G. Jenkins, E. Dupont, Cristian Massimi, C. Lederer, M. Diakaki, Niko Kivel, F. Cerutti, M. Krtička, Kathrin Göbel, A. S. Brown, Alexandru Negret, S. J. Lonsdale, J. Lerendegui-Marco, E. Mendoza, T. Martinez, B. Fernández-Domínguez, F. Käppeler, Jan Heyse, Mario Barbagallo, M.B. Gómez-Hornillos, A. Oprea, A. Kalamara, I. F. Gonçalves, Javier Praena, S. Lo Meo, P. M. Milazzo, A. Stamatopoulos, S. Heinitz, Ignacio Porras, F. Bečvář, T. J. Wright, D. Mancussi, Simone Gilardoni, Hideo Harada, Rene Reifarth, R. Cardella, A. Mengoni, O. Aberle, Peter Schillebeeckx, J. M. Quesada, L. Tassan-Got, Deniz Kurtulgil, R. Vlastou, P. Vaz, D. Radeck, E. Berthoumieux, L. Cosentino, N. V. Sosnin, Annamaria Mazzone, Petar Žugec, D. Bosnar, D. Macina, Carlos Guerrero, G. Tagliente, D. Cano-Ott, Y. Kadi, S. Valenta, Marco Calviani, A. G. Smith, Philip Woods, A. R. García, Emilio Andrea Maugeri, M. Kokkoris, E. Leal-Cidoncha, A. Gawlik, Thomas Rauscher, I. Duran, P. Kavrigin, Ralf Nolte, E. Griesmayer, L. A. Damone, 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, Lerendegui-Marco, J., Cortés-Giraldo, M.A., Guerrero, C., Quesada, J.M., Meo, S. Lo, Massimi, C., Barbagallo, M., Colonna, N., Mancussi, D., Mingrone, F., Sabaté-Gilarte, M., Vannini, G., Vlachoudis, V., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y.H., Chiaveri, E., Cortés, G., Cosentino, L., Damone, L.A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Göbel, K., Gómez-Hornillos, M.B., García, A.R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I.F., González, E., Griesmayer, E., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lonsdale, S.J., Macina, D., Marganiec, J., Martínez, T., Masi, A., Mastinu, P., Mastromarco, M., Maugeri, E.A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P.M., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Radeck, D., Rauscher, T., Reifarth, R., Rout, P.C., Rubbia, C., Ryan, J.A., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A.G., Sosnin, N.V., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Variale, V., Vaz, P., Ventura, A., Vlastou, R., Wallner, A., Warren, S., Woods, P.J., Wright, T., Ugec, P., Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. NEMEN - Nanoenginyeria de materials aplicats a l'energia, 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), and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear

Subjects
nTOF, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Montecarlo, Mètode de, Monte Carlo method, Context (language use), Neutron, 01 natural sciences, Nuclear physics, Physics and Astronomy (all), Informàtica [Àrees temàtiques de la UPC], Neutron flux, CERN, 0103 physical sciences, Spallation, 010306 general physics, Nuclear Experiment, Monte Carlo, Neutrons, Physics, Large Hadron Collider, Física [Àrees temàtiques de la UPC], 010308 nuclear & particles physics, Neutron radiation, Cascade, Nuclear Physics - Theory
Abstract

Monte Carlo (MC) simulations are an essential tool to determine fundamental features of a neutron beam, such as the neutron flux or the γ -ray background, that sometimes can not be measured or at least not in every position or energy range. Until recently, the most widely used MC codes in this field had been MCNPX and FLUKA. However, the Geant4 toolkit has also become a competitive code for the transport of neutrons after the development of the native Geant4 format for neutron data libraries, G4NDL. In this context, we present the Geant4 simulations of the neutron spallation target of the n TOF facility at CERN, done with version 10.1.1 of the toolkit. The first goal was the validation of the intra-nuclear cascade models implemented in the code using, as benchmark, the characteristics of the neutron beam measured at the first experimental area (EAR1), especially the neutron flux and energy distribution, and the time distribution of neutrons of equal kinetic energy, the so-called Resolution Function. The second goal was the development of aMonte Carlo tool aimed to provide useful calculations for both the analysis and planning of the upcoming measurements at the new experimental area (EAR2) of the facility., The research that led to these results has received funding from the EC FP7 Programme under the projects NEUTANDALUS (Grant No. 334315) and CHANDA (Grant No. 605203), and the Spanish Ministry of Economy and Competitiveness projects FPA2011-28770- C3-02, FPA2013-45083-P and FPA2014- 53290-C2-2-P. The simulations have been performed at the computing cluster FISATOM, hosted at CICA (Seville, Spain), and of INFN-CNAF, University of Bologna; we thank the staff of both institutions for the operational maintenance of the machines.

Published
2016

7. The new vertical neutron beam line at the CERN n_TOF facility design and outlook on the performance

Author

M. Kokkoris, A. K. Saxena, Arnaud Ferrari, J. Billowes, I. Duran, S. Girod, P. Vaz, Rugard Dressler, N. Kivel, G. Cortes, A. Tsinganis, M. A. Cortés-Giraldo, C. Weiß, Nicola Colonna, Alberto Ventura, M. Krtička, F. Calviño, M. Mastromarco, A. Kimura, J. Marganiec, R. Palomo Pinto, F. Gunsing, I. F. Gonçalves, F. Bečvář, R. J. W. Frost, T. Martinez, P. Kavrigin, E. Mendoza, Srinivasan Ganesan, R. Vlastou, E. Berthoumieux, M. Brugger, A. Stamatopoulos, Ralf Nolte, Cristian Massimi, Anton Wallner, A. Pavlik, C. Paradela, M. Bacak, V. Khryachkov, C. Domingo-Pardo, L. A. Damone, G. Vannini, Peter Schillebeeckx, E. Griesmayer, M. Sabaté-Gilarte, Fabio Belloni, Petar Žugec, Luigi Cosentino, D. Macina, Carlos Guerrero, M. Caamaño, G. Smith, V. Bécares, Mario Barbagallo, Roberto Losito, E. Leal-Cidoncha, F. Käppeler, M. Mirea, M. Licata, N. Patronis, Patrick Steinegger, J. L. Tain, E. Chiaveri, J. Balibrea-Correa, S. Warren, M. S. Robles, P. F. Mastinu, Thomas Rauscher, Damir Bosnar, S. Heinitz, Y. Kadi, D. López, E. Dupont, H. Leeb, D. Cano-Ott, V. Variale, I. Bergström, S. Valenta, A. Musumarra, M. Diakaki, J. Perkowski, P. V. Sedyshev, P. Ferreira, Marco Calviani, Hideo Harada, P. M. Milazzo, I. Porras, E. González-Romero, J. Lerendegui, V. Furman, T. J. Wright, K. Deo, Mario Weigand, C. Rubbia, V. Ketlerov, Tanja Heftrich, F. Mingrone, J. Andrzejewski, A. Riego-Perez, Saraswatula Venkata Suryanarayana, B. Fernández-Domínguez, E. Jericha, A. Gheorghe, V. Vlachoudis, Ariel Tarifeño-Saldivia, T. Glodariu, Paolo Finocchiaro, Dorothea Schumann, J. A. Ryan, Alberto Mengoni, G. Tagliente, A. Hernández-Prieto, Rene Reifarth, Stefan Schmidt, J. M. Quesada, L. Tassan-Got, Tatsuya Katabuchi, S. Barros, Francesca Matteucci, C. Beinrucker, O. Aberle, A. Goverdovski, S. Montesano, C. Lederer, Kathrin Göbel, Jan Heyse, L. Audouin, D. G. Jenkins, Javier Praena, S. Lo Meo, F. Cerutti, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. NERG - Grup de Recerca d'Enginyeria Nuclear, Mengoni, A., Lo Meo, S., 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), 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), n_TOF Collaboration, Weiß, C, Chiaveri, E., Girod, S., Vlachoudis, V., Aberle, O., Barros, S., Bergström, I., Berthoumieux, E., Calviani, M., Guerrero, C., Sabaté-Gilarte, M., Tsinganis, A., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea-Correa, J., Barbagallo, M., Bécares, V., Beinrucker, C., Belloni, F., Bečvář, F., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Cano-Ott, D., Cerutti, F., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L., Deo, K., Diakaki, M., Domingo-Pardo, C., Dupont, E., Durán, I., Dressler, R., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Frost, R., Furman, V., Ganesan, S., Gheorghe, A., Glodariu, T., Göbel, K., Gonçalves, I.F., González-Romero, E., Goverdovski, A., Griesmayer, E., Gunsing, F., Harada, H., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Kadi, Y., Käppeler, F., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui, J., Licata, M., López, D., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P.F., Mastromarco, M., Matteucci, F., Mendoza, E., Milazzo, P.M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Palomo Pinto, R., Paradela, C., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M.S., Rubbia, C., Ryan, J., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, G., Stamatopoulos, A., Steinegger, P., Suryanarayana, S.V., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Wright, T., Žugec, P., 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
Astrofísica, Nuclear and High Energy Physics, n-TOF facility, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Montecarlo, Mètode de, Física::Física de partícules [Àrees temàtiques de la UPC], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Astrophysics, 01 natural sciences, law.invention, Nuclear physics, FLUKA, law, Neutron flux, 0103 physical sciences, Neutron, Beam dump, 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Large Hadron Collider, Neutron cross-section measurement, Neutron time-of-flight, 010308 nuclear & particles physics, Collimator, Neutron radiation, Accelerators and Storage Rings, NATURAL SCIENCES. Physics, n_TOF facility, PRIRODNE ZNANOSTI. Fizika, Beamline, Physics::Accelerator Physics, neutron time-of-flight, neutron cross-section measurement
Abstract

At the neutron time-of-flight facility n_TOF at CERN a new vertical beam line was constructed in 2014, in order to extend the experimental possibilities at this facility to an even wider range of challenging cross-section measurements of interest in astrophysics, nuclear technology and medical physics. The design of the beam line and the experimental hall was based on FLUKA Monte Carlo simulations, aiming at maximizing the neutron flux, reducing the beam halo and minimizing the background from neutrons interacting with the collimator or back-scattered in the beam dump. The present paper gives an overview on the design of the beam line and the relevant elements and provides an outlook on the expected performance regarding the neutron beam intensity, shape and energy resolution, as well as the neutron and photon backgrounds., Engineering & Physical Sciences Research Council (EPSRC) EP/I003258/1, Science & Technology Facilities Council (STFC) ST/L005794/1 ST/J000159/1

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