Showing papers by "L. Tassan-Got published in 2019"
Istituto Nazionale di Fisica Nucleare1, University of Bologna2, CERN3, University of Łódź4, Université Paris-Saclay5, Vienna University of Technology6, Charles University in Prague7, University of Manchester8, University of Zagreb9, University of York10, University of Santiago de Compostela11, Polytechnic University of Catalonia12, University of Seville13, University of Bari14, Spanish National Research Council15, Paul Scherrer Institute16, Instituto Superior Técnico17, Joint Institute for Nuclear Research18, Goethe University Frankfurt19, Japan Atomic Energy Agency20, Karlsruhe Institute of Technology21, National Technical University of Athens22, University of Edinburgh23, ENEA24, German National Metrology Institute25, University of Catania26, University of Ioannina27, University of Vienna28, University of Granada29, University of Hertfordshire30, University of Basel31, Bhabha Atomic Research Centre32, Australian National University33
TL;DR: In this paper, the authors used the time-of-flight (TOF) technique at the n_TOF facility at CERN on isotopically enriched samples to perform cross section measurements on 155 Gd and 157 Gd.
Abstract: Neutron capture cross section measurements on 155 Gd and 157 Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n_TOF experimental area EAR1, at 185 m from the neutron source, with an array of 4 C 6 D 6 liquid scintillation detectors. At a neutron kinetic energy of 0.0253 eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for 155 Gd and 157 Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181 eV and 307 eV, respectively for 155 Gd and 157 Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1 keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of 2. 01 (28) × 10 - 4 and 2. 17 (41) × 10 - 4 ; average total radiative width of 106.8(14) meV and 101.1(20) meV and s-wave resonance spacing 1.6(2) eV and 4.8(5) eV for n + 155 Gd and n + 157 Gd systems, respectively.
23 citations
TL;DR: In this paper, the 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li (n,t) and 10B(n-alpha), with high resolution and in a high energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam.
Abstract: The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the reaction yields under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10÷30 keV 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 evaluated cross section in the 9÷18 keV neutron energy range is indeed overestimated, both in the recent updates of ENDF/B-VIII.0 and of the IAEA reference data. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The new, high accuracy results here reported may lead to a reduction of the uncertainty in the 1÷100 keV neutron energy region. Finally, the present data provide additional confidence on the recently re-evaluated cross section integral between 7.8 and 11 eV.
17 citations
TL;DR: In this paper, the authors calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar).
Abstract: Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The $(n,\gamma)$ cross section on $^{70}Ge$, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from $kT=5 keV$ to $kT=100 keV$ and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while they are systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80.
17 citations
University of Catania1, Istituto Nazionale di Fisica Nucleare2, ENEA3, University of Bologna4, CERN5, University of Łódź6, Université Paris-Saclay7, Vienna University of Technology8, Charles University in Prague9, University of Manchester10, University of Zagreb11, University of York12, University of Santiago de Compostela13, Polytechnic University of Catalonia14, University of Seville15, University of Bari16, Spanish National Research Council17, Paul Scherrer Institute18, Instituto Superior Técnico19, Joint Institute for Nuclear Research20, Goethe University Frankfurt21, Japan Atomic Energy Agency22, Karlsruhe Institute of Technology23, National Technical University of Athens24, University of Edinburgh25, German National Metrology Institute26, University of Ioannina27, University of Vienna28, University of Granada29, University of Hertfordshire30, University of Basel31, Bhabha Atomic Research Centre32, Australian National University33
TL;DR: In this paper, the authors measured the 235U(n, f) cross section at n_TOF relative to 6Li n, t and 10B n,α, with high resolution (L= 183. 49 (2) m) and in a wide energy range (25meV-170keV).
Abstract: The 235U(n, f) cross section was measured at n_TOF relative to 6Li(n, t) and 10B(n,α) , 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 235U(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·eV has been extracted for the cross section integral between 7.8 and 11eV, confirming the value of 247. 5 ± 3 b·eV recently established as a standard.
13 citations
Goethe University Frankfurt1, University of Edinburgh2, Instituto Superior Técnico3, University of Łódź4, University of Seville5, CERN6, Université Paris-Saclay7, Paul Scherrer Institute8, ENEA9, Charles University in Prague10, Vienna University of Technology11, Istituto Nazionale di Fisica Nucleare12, University of Zagreb13, University of Santiago de Compostela14, Polytechnic University of Catalonia15, University of Bari16, Bhabha Atomic Research Centre17, National Technical University of Athens18, Spanish National Research Council19, University of Manchester20, Joint Institute for Nuclear Research21, Japan Atomic Energy Agency22, University of York23, Karlsruhe Institute of Technology24, Tokyo Institute of Technology25, University of Bologna26, University of Trieste27, University of Catania28, German National Metrology Institute29, University of Ioannina30, University of Vienna31, University of Granada32, University of Hertfordshire33, University of Basel34, Australian National University35
TL;DR: In this paper, the authors measured the stellar cross section at kT = 30 keV, which is 1.5 to 1.7 times higher than most theoretical predictions, and showed that the new cross sections result in a substantial decrease of 73Ge produced in stars, which would explain the low isotopic abundance of 73 Ge in the solar system.
11 citations
01 Jan 2019-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In counting experiments associated with pulsed sources, a high data collection rate can lead to considerably large counting losses, especially in the counting experiments as mentioned in this paper, where the counting losses can be very large.
Abstract: In counting experiments associated with pulsed sources, a high data collection rate can lead to considerably large counting losses, especially in the
4 citations
Université Paris-Saclay1, Vienna University of Technology2, CERN3, University of Bordeaux4, University of Łódź5, Istituto Nazionale di Fisica Nucleare6, Charles University in Prague7, University of Manchester8, University of Zagreb9, University of York10, University of Santiago de Compostela11, Polytechnic University of Catalonia12, University of Seville13, University of Bari14, Spanish National Research Council15, Paul Scherrer Institute16, Instituto Superior Técnico17, Joint Institute for Nuclear Research18, Goethe University Frankfurt19, Japan Atomic Energy Agency20, Karlsruhe Institute of Technology21, National Technical University of Athens22, University of Edinburgh23, ENEA24, University of Bologna25, German National Metrology Institute26, University of Catania27, University of Ioannina28, University of Vienna29, University of Granada30, University of Hertfordshire31, University of Basel32, Bhabha Atomic Research Centre33, Australian National University34
TL;DR: In this article, the authors used the Total Absorption Calorimeter (TAC) of n_TOF coupled with a novel compact ionization chamber as fission detector to measure the capture-to-fission ratio.
Abstract: $^{233}$U is of key importance among the fissile nuclei in the Th-U fuel cycle. A particularity of 233U is its small neutron capture cross-section, which is on average about one order of magnitude lower than the fission cross-section. The accuracy in the measurement of the 233U capture cross-section depends crucially on an efficient capture-fission discrimination, thus a combined set-up of fission and $\gamma$-detectors is needed. A measurement of the $^{233}$U capture cross-section and capture-to-fission ratio was performed at the CERN n_TOF facility. The Total Absorption Calorimeter (TAC) of n_TOF was employed as $\gamma$-detector coupled with a novel compact ionization chamber as fission detector. A brief description of the experimental set-up will be given, and essential parts of the analysis procedure as well as the preliminary response of the set-up to capture are presented and discussed.
3 citations
Japan Atomic Energy Agency1, CERN2, University of Łódź3, Université Paris-Saclay4, Vienna University of Technology5, Istituto Nazionale di Fisica Nucleare6, Charles University in Prague7, University of Catania8, University of Manchester9, University of Zagreb10, University of York11, University of Perugia12, University of Santiago de Compostela13, Spanish National Research Council14, Polytechnic University of Catalonia15, University of Seville16, University of Bari17, National Technical University of Athens18, University of Edinburgh19, Paul Scherrer Institute20, University of Ioannina21, Joint Institute for Nuclear Research22, Goethe University Frankfurt23, Instituto Superior Técnico24, Karlsruhe Institute of Technology25, Tokyo Institute of Technology26, ENEA27, University of Bologna28, University of Trieste29, German National Metrology Institute30, University of Granada31, University of Vienna32, University of Hertfordshire33, University of Basel34, Bhabha Atomic Research Centre35, Helmholtz-Zentrum Dresden-Rossendorf36, Australian National University37
TL;DR: In this article, the authors measured both neutron capture cross sections at the n_TOF Experimental Area 2 (EAR-2) with three C6 D6 detectors and also at Area 1 with the TAC.
Abstract: The neutron capture reactions of the $^{244}$Cm and $^{246}$Cm isotopes open the path for the formation of heavier Cm isotopes and heavier elements such as Bk and Cf in a nuclear reactor. In addition, both isotopes belong to the minor actinides with a large contribution to the decay heat and to the neutron emission in irradiated fuels. There are only two previous $^{244}$Cm and $^{246}$Cm capture cross section measurements: one in 1969 using a nuclear explosion [1] and the most recent data measured at J-PARC in 2010 [2]. The data for both isotopes are very scarce due to the difficulties in performing the measurements: high intrinsic activity of the samples and limited facilities capable of providing isotopically enriched samples.We have measured both neutron capture cross sections at the n_TOF Experimental Area 2 (EAR-2) with three C6 D6 detectors and also at Area 1 (EAR-1) with the TAC. Preliminary results assessing the quality and limitations (back-ground subtraction, measurement technique and counting statistics) of this new experimental datasets are presented and discussed.
3 citations
TL;DR: In this paper, the 235 U(n,f) low-background and high-resolution experimental data obtained at the CERN-nTOF facility is combined with previous high resolution experimental data, in order to produce a very fine grid dataset with normalisation to the IAEA Reference file.
Abstract: 235 U neutron-induced fission cross-section is commonly used as reference for determining other isotope fission cross-section. However, below 150 keV this cross section is only included as Standard at the thermal point and recently its integral value between 7.8 eV and 11 eV [1]. The resolved resonance region, spanning up to 2.25 keV, has been reevaluated with high resolution in the last ENDF/B-VIII release [2] and a SAMMY resonance analysis was done by L. Leal et al. [3] including the CERN-nTOF experimental work of Paradela el al. [4] up to 10 keV, taken into account the IAEA Reference file.In this work the 235 U(n,f) low-background and high-resolution experimental data obtained at the CERN-nTOF facility is combined with previous high-resolution experimental data, in order to produce a very fine grid dataset with normalisation to the IAEA Reference file. The extremelyhigh energy calibration required to reproduce the resonance sharp profiles is based on the nTOF DAQ system with a resolution below 0.1% with reference to the 8.78 eV resonance and to the sharp Al(n,g) capture dip at 5.904 keV.The comparison of the so-evaluated profile with the experimental data and with the evaluated ones will be discussed.
2 citations
TL;DR: In this article, a brief historical review focused on total energy detectors is presented to illustrate how advances in instrumentation have led, over the years, to the assessment and discovery of many new aspects of $s$-process nucleosynthesis and to the progressive refinement of theoretical models of stellar evolution.
Abstract: The idea of slow-neutron capture nucleosynthesis formulated in 1957 triggered a tremendous experimental effort in different laboratories worldwide to measure the relevant nuclear physics input quantities, namely ($n,\gamma$) cross sections over the stellar temperature range (from few eV up to several hundred keV) for most of the isotopes involved from Fe up to Bi. A brief historical review focused on total energy detectors will be presented to illustrate how, advances in instrumentation have led, over the years, to the assessment and discovery of many new aspects of $s$-process nucleosynthesis and to the progressive refinement of theoretical models of stellar evolution. A summary will be presented on current efforts to develop new detection concepts, such as the Total-Energy Detector with $\gamma$-ray imaging capability (i-TED). The latter is based on the simultaneous combination of Compton imaging with neutron time-of-flight (TOF) techniques, in order to achieve a superior level of sensitivity and selectivity in the measurement of stellar neutron capture rates.
2 citations
Université Paris-Saclay1, SIDI2, Charles University in Prague3, CERN4, University of Łódź5, Spanish National Research Council6, Vienna University of Technology7, Istituto Nazionale di Fisica Nucleare8, Goethe University Frankfurt9, University of Manchester10, University of Zagreb11, University of York12, University of Perugia13, University of Santiago de Compostela14, Polytechnic University of Catalonia15, University of Seville16, University of Bari17, University of Edinburgh18, Paul Scherrer Institute19, German National Metrology Institute20, University of Ioannina21, Joint Institute for Nuclear Research22, Instituto Superior Técnico23, Helmholtz-Zentrum Dresden-Rossendorf24, Karlsruhe Institute of Technology25, Japan Atomic Energy Agency26, National Technical University of Athens27, University of Bologna28, ENEA29, University of Catania30, University of Granada31, University of Vienna32, University of Basel33, University of Hertfordshire34, Bhabha Atomic Research Centre35, Australian National University36
TL;DR: In this paper, the gamma de-excitation cascades in radiative capture on 234 U with the Total Absorption Calorimeter at n_TOF at CERN are studied using the measurement of the gamma multiplicity and gamma spectra that can be compared with numerical simulations.
Abstract: The accurate calculations of neutron-induced reaction cross sections are relevant for many nuclear applications. The photon strength functions and nuclear level densities are essential inputs for such calculations. These quantities for 235 U are studied using the measurement of the gamma de-excitation cascades in radiative capture on 234 U with the Total Absorption Calorimeter at n_TOF at CERN. This segmented 4π gamma calorimeter is designed to detect gamma rays emitted from the nucleus with high efficiency. This experiment provides information on gamma multiplicity and gamma spectra that can be compared with numerical simulations. The code DICEBOXC is used to simulate the gamma cascades while GEANT4 is used for the simulation of the interaction of these gammas with the TAC materials. Available models and their parameters are being tested using the present data. Some preliminary results of this ongoing study are presented and discussed.
Université Paris-Saclay1, National Technical University of Athens2, CERN3, Istituto Nazionale di Fisica Nucleare4, University of Ioannina5, University of Bologna6, University of Manchester7, University of Catania8, University of Łódź9, Spanish National Research Council10, Vienna University of Technology11, University of Zagreb12, University of York13, University of Perugia14, University of Santiago de Compostela15, Polytechnic University of Catalonia16, University of Seville17, University of Bari18, University of Edinburgh19, Paul Scherrer Institute20, German National Metrology Institute21, Instituto Superior Técnico22, Joint Institute for Nuclear Research23, Goethe University Frankfurt24, Helmholtz-Zentrum Dresden-Rossendorf25, Karlsruhe Institute of Technology26, Japan Atomic Energy Agency27, Charles University in Prague28, ENEA29, University of Granada30, University of Vienna31, Bhabha Atomic Research Centre32, Australian National University33
TL;DR: In this paper, a special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV.
Abstract: Since its start in 2001 the n_TOF collaboration developed a measurement program on fission, in view of advanced fuels in new generation reactors. A special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV. Moreover fission fragment angular distributions have also been measured. An overview of the cross section results achieved with different detectors is presented, including a discussion of the 237 Np case where discrepancies showed up between different detector systems. The results on the anisotropy of the fission fragments and its implication on the mechanism of neutron absorption, and in applications, are also shown.
Istituto Nazionale di Fisica Nucleare1, CERN2, University of Łódź3, Université Paris-Saclay4, Spanish National Research Council5, Goethe University Frankfurt6, University of Manchester7, University of Zagreb8, University of York9, University of Santiago de Compostela10, Polytechnic University of Catalonia11, University of Seville12, University of Edinburgh13, Paul Scherrer Institute14, German National Metrology Institute15, University of Ioannina16, Joint Institute for Nuclear Research17, Instituto Superior Técnico18, Helmholtz-Zentrum Dresden-Rossendorf19, Karlsruhe Institute of Technology20, Japan Atomic Energy Agency21, Charles University in Prague22, National Technical University of Athens23, University of Granada24, University of Vienna25, University of Basel26, Bhabha Atomic Research Centre27, Australian National University28
TL;DR: A considerable amount of (n,\(\gamma \)) reactions has been studied, so far, at the neutron time-of-flight facility n_TOF at CERN as discussed by the authors, which aims at determining and improving cross sections for a number of isotopes relevant to s-process nucleosynthesis.
Abstract: A considerable amount of (n,\(\gamma \)) reactions has been studied, so far, at the neutron time-of-flight facility n_TOF at CERN. The experimental program aims at determining and improving cross sections for a number of isotopes relevant to s-process nucleosynthesis. A brief summary of some physical cases related to the s-process nucleosyntheis is presented in this work together with ongoing experiments and challenging future programs.
Japan Atomic Energy Agency1, CERN2, University of Łódź3, University of Paris-Sud4, Spanish National Research Council5, Vienna University of Technology6, Istituto Nazionale di Fisica Nucleare7, Charles University in Prague8, University of Catania9, University of Manchester10, University of Zagreb11, University of York12, University of Perugia13, University of Santiago de Compostela14, Polytechnic University of Catalonia15, University of Bari16, National Technical University of Athens17, University of Edinburgh18, Paul Scherrer Institute19, University of Ioannina20, Instituto Superior Técnico21, Joint Institute for Nuclear Research22, Goethe University Frankfurt23, Karlsruhe Institute of Technology24, ENEA25, University of Bologna26, University of Trieste27, German National Metrology Institute28, University of Granada29, University of Vienna30, University of Basel31, Bhabha Atomic Research Centre32, Helmholtz-Zentrum Dresden-Rossendorf33, Australian National University34
TL;DR: In this paper, the authors measured the neutron capture cross section with isotopically enriched samples of Cm and Cm provided by JAEA, covering the range from 1 eV to 250 eV in the n_TOF Experimental Area 2 (EAR-2).
Abstract: The neutron capture reactions of the \(^{244}\)Cm and \(^{246}\)Cm isotopes open the path for the formation of heavier Cm isotopes and of heavier elements such as Bk and Cf in a nuclear reactor. In addition, both isotopes belong to the minor actinides with a large contribution to the decay heat and to the neutron emission in irradiated fuels proposed for the transmutation of nuclear waste and fast critical reactors. The available experimental data for both isotopes are very scarce. We measured the neutron capture cross section with isotopically enriched samples of \(^{244}\)Cm and \(^{246}\)Cm provided by JAEA. The measurement covers the range from 1 eV to 250 eV in the n_TOF Experimental Area 2 (EAR-2). In addition, a normalization measurement with the \(^{244}\)Cm sample was performed at Experimental Area 1 (EAR-1) with the Total Absorption Calorimeter (TAC).
01 Aug 2019
TL;DR: In this paper, an accurate measurement of Be(n,p) cross section has been performed at n TOF, with a pure Be target produced by implantation of a Be beam at ISOLDE.
Abstract: One of the most puzzling problems in Nuclear Astrophysics is the “Cosmological Lithium Problem”, i.e the discrepancy between the primordial abundance of Li observed in metal poor halo stars (Asplund et al. in Astrophys J 644:229–259, 2006, [1]), and the one predicted by Big Bang Nucleosynthesis (BBN). One of the reactions that could have an impact on the problem is Be(n,p) Li. Despite of the importance of this reaction in BBN, the cross-section has never been directly measured at the energies of interest for BBN. Taking advantage of the innovative features of the second experimental area at the n TOF facility at CERN (Sabate-Gilarte et al. in Eur Phys J A 53:210, 2017, [2]; Weiss et al. in NIMA 799:90, 2015, [3]), an accurate measurement of Be(n,p) cross section has been recently performed at n TOF, with a pure Be target produced by implantation of a Be beam at ISOLDE. The mesurement started in April 2016 and lasted for two months. The experimental procedure, the setup used in the measurement and the results obtained so far will be here presented.
Spanish National Research Council1, CERN2, University of Łódź3, Université Paris-Saclay4, Vienna University of Technology5, Istituto Nazionale di Fisica Nucleare6, Charles University in Prague7, University of Catania8, University of Manchester9, University of Zagreb10, University of York11, University of Perugia12, University of Santiago de Compostela13, Polytechnic University of Catalonia14, University of Bari15, National Technical University of Athens16, University of Edinburgh17, Paul Scherrer Institute18, University of Ioannina19, Instituto Superior Técnico20, Joint Institute for Nuclear Research21, Goethe University Frankfurt22, Karlsruhe Institute of Technology23, Japan Atomic Energy Agency24, ENEA25, University of Bologna26, University of Trieste27, German National Metrology Institute28, University of Granada29, University of Vienna30, University of Basel31, University of Valencia32, Bhabha Atomic Research Centre33, Helmholtz-Zentrum Dresden-Rossendorf34, Australian National University35
TL;DR: The i-TED detector as mentioned in this paper uses the Compton principle to select events produced in the sample and discard background events, which can be used to distinguish between true capture gamma rays from the sample under study and neutron induced gamma rays generated in the surroundings of the setup.
Abstract: Neutron capture cross section measurements are of fundamental importance for the study of the slow process of neutron capture, so called s-process. This mechanism is responsible for the formation of most elements heavier than iron in the Universe. To this aim, installations and detectors have been developed, as total energy radiation C 6 D 6 detectors. However, these detectors can not distinguish between true capture gamma rays from the sample under study and neutron induced gamma rays produced in the surroundings of the setup. To improve this situation, we propose (Domingo Pardo in Nucl Instr Meth Phys Res A 825:78–86, 2016, [1]) the use of the Compton principle to select events produced in the sample and discard background events. This involves using detectors capable of resolving the interaction position of the gamma ray inside the detector itself, as well as a high energy resolution. These are the main features of i-TED, a total energy detector capable of gamma ray imaging. Such system is being developed at the “Gamma Spectroscopy and Neutrons Group” at IFIC (http://webgamma.ific.uv.es/gamma/es/, [2]), in the framework of the ERC-funded project HYMNS (High sensitivitY and Measurements of key stellar Nucleo-Synthesis reactions). This work summarizes first tests with neutron beam at CERN n _ TOF.