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Author n_TOF Collaboration (Amaducci, S. et al); Domingo-Pardo, C.; Tain, J.L. url  doi
openurl 
  Title Measurement of the U-235(n, f) cross section relative to the Li-6(n, t) and B-10(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOF Type Journal Article
  Year 2019 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A  
  Volume 55 Issue 7 Pages 120 - 19pp  
  Keywords  
  Abstract .The U-235(n, f ) cross section was measured at n_TOF relative to Li-6(n, t) and B-10(n,alpha) , with high resolution ( L=183.49(2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the U-235(n, f ) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. Finally, from the present data, a value of 249.7 +/- 1.4( stat )+/- 0.94( syst ) b<bold>eV has been extracted for the cross section integral between </bold>7.8 and 11eV, confirming the value of 247.5 +/- 3 b<bold>eV recently established as a standard</bold>.  
  Address (up) [Amaducci, S.; Cosentino, L.; Finocchiaro, P.; Musumarra, A.] INFN, Lab Nazl Sud, Catania, Italy, Email: finocchiaro@lns.infn.it  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6001 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000477050900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4083  
Permanent link to this record
 

 
Author AGATA Collaboration (Avigo, R. et al); Domingo-Pardo, C.; Gadea, A.; Gonzalez, V. doi  openurl
  Title Low-lying electric dipole gamma-continuum for the unstable Fe-62(,)64 nuclei: Strength evolution with neutron number Type Journal Article
  Year 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 811 Issue Pages 135951 - 6pp  
  Keywords Fe-64; Fe-62; Nuclear structure; Dipole excitation around neutron threshold  
  Abstract The gamma-ray emission from the nuclei Fe-62,Fe-64 following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe-62,Fe-64 were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The gamma decay was detected with AGATA. From the measured gamma-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1(-) states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.  
  Address (up) [Avigo, R.; Wieland, O.; Bracco, A.; Camera, F.; Benzoni, G.; Blasi, N.; Bottoni, S.; Brambilla, S.; Crespi, F. C. L.; Leoni, S.; Million, B.; Morales, A., I; Pullia, A.; Riboldi, S.] Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy, Email: oliver.wieland@mi.infn.it  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000612225400080 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4700  
Permanent link to this record
 

 
Author Babiano, V.; Balibrea, J.; Caballero, L.; Calvo, D.; Ladarescu, I.; Mira Prats, S.; Domingo-Pardo, C. url  doi
openurl 
  Title First i-TED demonstrator: A Compton imager with Dynamic Electronic Collimation Type Journal Article
  Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 953 Issue Pages 163228 - 9pp  
  Keywords Compton imaging; Position-sensitive detectors; Monolithic crystals; Silicon photomultiplier  
  Abstract i-TED consists of both a total energy detector and a Compton camera primarily intended for the measurement of neutron capture cross sections by means of the simultaneous combination of neutron time-of-flight (TOF) and gamma-ray imaging techniques. TOF allows one to obtain a neutron-energy differential capture yield, whereas the imaging capability is intended for the discrimination of radiative background sources, that have a spatial origin different from that of the capture sample under investigation. A distinctive feature of i-TED is the embedded Dynamic Electronic Collimation (DEC) concept, which allows for a trade-off between efficiency and image resolution. Here we report on some general design considerations and first performance characterization measurements made with an i-TED demonstrator in order to explore its gamma-ray detection and imaging capabilities.  
  Address (up) [Babiano, V; Balibrea, J.; Caballero, L.; Calvo, D.; Ladarescu, I; Mira Prats, S.; Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: domingo@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000506419900045 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4250  
Permanent link to this record
 

 
Author Babiano, V.; Caballero, L.; Calvo, D.; Ladarescu, I.; Olleros, P.; Domingo-Pardo, C. url  doi
openurl 
  Title gamma-Ray position reconstruction in large monolithic LaCl3(Ce) crystals with SiPM readout Type Journal Article
  Year 2019 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 931 Issue Pages 1-22  
  Keywords Gamma-ray; Position-sensitive detectors; Monolithic crystals; Spatial resolution; Neural networks  
  Abstract We report on the spatial response characterization of large LaCl3(Ce) monolithic crystals optically coupled to 8 x 8 pixel silicon photomultiplier (SiPM) sensors. A systematic study has been carried out for 511 keV gamma-rays using three different crystal thicknesses of 10 mm, 20 mm and 30 mm, all of them with planar geometry and a base size of 50 x 50 mm(2). In this work we investigate and compare two different approaches for the determination of the main gamma-ray hit location. On one hand, methods based on the fit of an analytical model for the scintillation light distribution provide the best results in terms of linearity and field of view, with spatial resolutions close to similar to 1 mm FWHM. On the other hand, position reconstruction techniques based on neural networks provide similar linearity and field-of-view, becoming the attainable spatial resolution similar to 3 mm FWHM. For the third space coordinate z or depth-of-interaction we have implemented an inverse linear calibration approach based on the cross-section of the measured scintillation-light distribution at a certain height. The detectors characterized in this work are intended for the development of so-called Total Energy Detectors with Compton imaging capability (i-TED), aimed at enhanced sensitivity and selectivity measurements of neutron capture cross sections via the time-of-flight (TOF) technique.  
  Address (up) [Babiano, V; Caballero, L.; Calvo, D.; Ladarescu, I; Olleros, P.; Domingo-Pardo, C.] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: domingo@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000466151600001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4015  
Permanent link to this record
 

 
Author n_TOF Collaboration (Bacak, M. et al); Domingo-Pardo, C.; Tain, J.L. doi  openurl
  Title A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes Type Journal Article
  Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 969 Issue Pages 163981 - 10pp  
  Keywords Fission detector; U-233; n_TOF; Time-of-flight  
  Abstract In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the U-233(n, gamma) cross-section at the nTOF facility at CERN, where it was coupled to the nTOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.  
  Address (up) [Bacak, M.; Gunsing, F.; Vlachoudis, V.; Aberle, O.; Calviani, M.; Cardella, R.; Cerutti, F.; Chiaveri, E.; Ferrari, A.; Gilardoni, S.; Kadi, Y.; Macina, D.; Masi, A.; Mingrone, F.; Rubbia, C.; Sabate-Gilarte, M.; Zugec, P.] CERN, European Org Nucl Res, Geneva, Switzerland, Email: michael.bacak@cern.ch  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000536792400015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4413  
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Author Balibrea-Correa, J.; Lerendegui-Marco, J.; Babiano-Suarez, V.; Caballero, L.; Calvo, D.; Ladarescu, I.; Olleros-Rodriguez, P.; Domingo-Pardo, C. url  doi
openurl 
  Title Machine Learning aided 3D-position reconstruction in large LaCl3 crystals Type Journal Article
  Year 2021 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 1001 Issue Pages 165249 - 17pp  
  Keywords Gamma-ray; Position sensitive detectors; Monolithic crystals; Compton imaging; Machine Learning; Convolutional Neural Networks; Total Energy Detector; Neutron capture cross-section  
  Abstract We investigate five different models to reconstruct the 3D gamma-ray hit coordinates in five large LaCl3(Ce) monolithic crystals optically coupled to pixelated silicon photomultipliers. These scintillators have a base surface of 50 x 50 mm(2) and five different thicknesses, from 10 mm to 30 mm. Four of these models are analytical prescriptions and one is based on a Convolutional Neural Network. Average resolutions close to 1-2 mm fwhm are obtained in the transverse crystal plane for crystal thicknesses between 10 mm and 20 mm using analytical models. For thicker crystals average resolutions of about 3-5 mm fwhm are obtained. Depth of interaction resolutions between 1 mm and 4 mm are achieved depending on the distance of the interaction point to the photosensor surface. We propose a Machine Learning algorithm to correct for linearity distortions and pin-cushion effects. The latter allows one to keep a large field of view of about 70%-80% of the crystal surface, regardless of crystal thickness. This work is aimed at optimizing the performance of the so-called Total Energy Detector with Compton imaging capability (i-TED) for time-of-flight neutron capture cross-section measurements.  
  Address (up) [Balibrea-Correa, J.; Lerendegui-Marco, J.; Babiano-Suarez, V.; Caballero, L.; Calvo, D.; Ladarescu, I.; Olleros-Rodriguez, P.; Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: javier.balibrea@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000641308300007 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4803  
Permanent link to this record
 

 
Author Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V.; Ladarescu, I.; Redondo, M.L.; Tain, J.L.; Tolosa, A.; Domingo-Pardo, C.; Calvino, F.; Casanovas, A.; Tarifeño-Saldivia, A.; Alcayne, V.; Cano-Ott, D.; Martinez, T.; Guerrero, C.; Barbagallo, M.; Macina, D.; Bacak, M. doi  openurl
  Title A first prototype of C6D6 total-energy detector with SiPM readout for neutron capture time-of-flight experiments Type Journal Article
  Year 2021 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 985 Issue Pages 164709 - 8pp  
  Keywords Silicon photomultiplier; Radiation detectors; Time-of-flight; Radiative capture; Total energy detector; Pulse-height weighting technique  
  Abstract Low efficiency total-energy detectors (TEDs) are one of the main tools for neutron capture cross section measurements utilizing the time-of-flight (TOF) technique. State-of-the-art TEDs are based on a C6D6 liquid-scintillation cell optically coupled to a fast photomultiplier tube. The large photomultiplier tube represents yet a significant contribution to the so-called neutron sensitivity background, which is one of the most conspicuous sources of uncertainty in this type of experiments. Here we report on the development of a first prototype of a TED based on a silicon-photomultiplier (SiPM) readout, thus resulting in a lightweight and much more compact detector. Apart from the envisaged improvement in neutron sensitivity, the new system uses low voltage (+28 V) and low current supply (-50 mA), which is more practical than the-kV supply required by conventional photomultipliers. One important difficulty hindering the earlier implementation of SiPM readout for this type of detector was the large capacitance for the output signal when all pixels of a SiPM array are summed together. The latter leads to long pulse rise and decay times, which are not suitable for time-of-flight experiments. In this work we demonstrate the feasibility of a Schottky-diode multiplexing readout approach, that allows one to preserve the excellent timing properties of SiPMs, hereby paving the way for their implementation in future neutron TOF experiments.  
  Address (up) [Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V; Ladarescu, I; Redondo, M. Lopez; Tain, J. L.; Tolosa, A.; Domingo-Pardo, C.] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: dacaldia@ific.uv.es;  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000592358200019 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4638  
Permanent link to this record
 

 
Author Balibrea-Correa, J.; Lerendegui-Marco, J.; Ladarescu, I.; Guerrero, C.; Rodriguez-Gonzalez, T.; Jimenez-Ramos, M.C.; Fernandez-Martinez, B.; Domingo-Pardo, C. url  doi
openurl 
  Title Hybrid in-beam PET- and Compton prompt-gamma imaging aimed at enhanced proton-range verification Type Journal Article
  Year 2022 Publication European Physical Journal Plus Abbreviated Journal Eur. Phys. J. Plus  
  Volume 137 Issue 11 Pages 1258 - 18pp  
  Keywords  
  Abstract We report on a hybrid in-beam PET and prompt-gamma Compton imaging system aimed at quasi real-time ion-range verification in proton-therapy treatments. Proof-of-concept experiments were carried out at the radiobiology beam line of the CNA cyclotron facility using a set of two synchronous Compton imagers and different target materials. The time structure of the 18 MeV proton beam was shaped with a series of beam-on and beam-off intervals, thereby mimicking a pulsed proton beam on a long time scale. During beam-on intervals, Compton imagingwas performed utilizing the high energy. -rays promptly emitted from the nuclear reactions occurring in the targets. In the course of the beam-off intervals in situ positron-emission tomography was accomplished with the same imagers using the beta+ decay of activated nuclei. The targets used were stacks of different materials covering also various proton ranges and energies. A systematic study on the performance of these two complementary imaging techniques is reported and the experimental results interpreted on the basis ofMonte Carlo calculations. The results demonstrate the possibility to combine both imaging techniques in a concomitant way, where high-efficiency prompt-gamma imaging is complemented with the high spatial accuracy of PET. Empowered by these results we suggest that a pulsed beam with a suitable duty cycle, in conjunction with in situ Compton- and PET-imaging may help to attain complementary information and quasi real-time range monitoring with high accuracy.  
  Address (up) [Balibrea-Correa, J.; Lerendegui-Marco, J.; Ladarescu, I; Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: javier.balibrea@ific.uv.es  
  Corporate Author Thesis  
  Publisher Springer Heidelberg Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2190-5444 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000886327900002 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 5420  
Permanent link to this record
 

 
Author n_TOF Collaboration (Balibrea-Correa, J. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title Measurement of the alpha ratio and (n, gamma) cross section of U-235 from 0.2 to 200 eV at n_TOF Type Journal Article
  Year 2020 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 102 Issue 4 Pages 044615 - 18pp  
  Keywords  
  Abstract We measured the neutron capture-to-fission cross-section ratio (alpha ratio) and the capture cross section of U-235 between 0.2 and 200 eV at the nTOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the nTOF BaF2 Total Absorption Calorimeter (TAC), used for detection of gamma 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 Li-6(n, t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the U-235(n, f) cross section between 7.8 and 11 eV was then used for its absolute normalization. The alpha 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 U-235 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.  
  Address (up) [Balibrea-Correa, J.; Mendoza, E.; Cano-Ott, D.] Ctr Invest Energet Medioambientales & Tecnol, CIEMAT, Madrid, Spain, Email: emilio.mendoza@ciemat.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000579839000003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4575  
Permanent link to this record
 

 
Author n_TOF Collaboration (Barbagallo, M. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. url  doi
openurl 
  Title Be-7(n,alpha)He-4 Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN Type Journal Article
  Year 2016 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 117 Issue 15 Pages 152701 - 7pp  
  Keywords  
  Abstract The energy-dependent cross section of the (7)Bed(n,alpha)He-4 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 Be-7 and by the low reaction cross section have been overcome at nTOF 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 nTOF facility at CERN, the availability of a sufficient amount of chemically pure Be-7, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two Si-Be-7-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.  
  Address (up) [Barbagallo, M.; Colonna, N.; Damone, L.; Mastromarco, M.; Mazzone, A.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: nicola.colonna@ba.infn.it  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000384479300003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2822  
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