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In this paper, we report a detailed study on the de-excitation of the 46Ti compound nucleus populated by means of four different reactions: 16O + 30Si at 7 and 8 AMeV, 18O + 28Si at 7 AMeV and 19F + 27Al at 7 AMeV. The GARFIELD detection array was used to measure the light charged particles and the heavy fragments emitted. This setup covers a large fraction of the solid angle with high-granularity. Complete events are chosen through total charge (Z TOT = 22) detection. Fusion-evaporation events are selected based on the condition that only one heavy fragment is detected in coincidence with the light charged particles. The analysis of global observables, such as charge distribution and light charged particle multiplicities, is compatible with the formation of a thermalized compound nucleus for all the four reactions. Nevertheless, an enhanced emission of α-particles with respect to a pure statistical picture is observed at very forward angles (α-particles.

Parallel robots with configurable platforms are a class of robots in which the end-effector has an inner mobility, so that its overall shape can be reconfigured: in most cases, the end-effector is thus a closed-loop kinematic chain composed of rigid links. These robots have a greater flexibility in their motion and control with respect to rigid-platform parallel architectures, but their kinematics is more challenging to analyze. In our work, we consider n-RRR planar configurable robots, in which the end-effector is a chain composed of n links and revolute joints, and is controlled by n rotary actuators located on the base of the mechanism. In particular, we study the geometrical design of such robots and their direct and inverse kinematics for n=4, n=5 and n=6, we employ the bilateration method, which can simplify the kinematic analysis and allows us to generalize the approach and the results obtained for the 3-RRR mechanism to n-RRR robots (with n&gt, 3). Then, we study the singularity configurations of these robot architectures. Finally, we present the results from experimental tests that have been performed on a 5&ndash, RRR robot prototype.

The design, realization and operation of a prototype or “demonstrator” version of an active target and time projection chamber (ACTAR TPC) for experiments in nuclear physics is presented in detail. The heart of the detection system features a micromegas gas amplifier coupled to a high-density pixelated pad plane with square pad sizes of 2 × 2 mm 2 . The detector has been thoroughly tested with several different gas mixtures over a wide range of pressures and using a variety of sources of ionizing radiation including laser light, an α -particle source and heavy-ion beams of 24Mg and 58Ni accelerated to energies of 4.0 MeV/u. Results from these tests and characterization of the detector response over a wide range of operating conditions will be described. These developments have served as the basis for the design of a larger detection system that is presently under construction.

SpecMAT is a magnetic active target (AT) for transfer reaction studies with low-intensity radioactive ion beams at the ISOLDE facility (CERN). SpecMAT combines two types of detectors: a gas-filled time projection chamber (TPC), the core detector for tracking charged particles emitted in nuclear reactions, and an array of auxiliary scintillation detectors for in-flight γ -ray spectroscopy . All active target components are optimised for operation in a strong background magnetic field. The TPC has a cylindrical shape. Its electron detector is a bulk Micromegas segmented into 2916 triangular pads for sampling charged particle tracks . The scintillation array is composed of 45 detectors with cubic 48 × 48 × 48 mm 3 CeBr3 crystals. The General Electronics for TPC (GET) is used in SpecMAT to read out both detector types allowing correlation of the detected γ -rays with the TPC events. This article describes the SpecMAT active target and its characterisation with the α -decay of 241Am. A γ -ray spectrum obtained in correlation with 3D tracks left by charged particles in an active target is reported for the first time for such detectors.

Trabajo presentado en el International Conference of IFToMM ITALY, celebrada en Nápoles (Italia) del 9 al 11 de septiembre de 2020, Parallel robots with a configurable platform are a class of parallel robots in which the end-effector is a closed-loop kinematic chain. In n-RRR planar robots the end-effector is a n-bar chain controlled by n actuated RRR chains connected to the base. We solve the direct kinematic problem for 4, 5 and 6-RRR mechanisms by using bilateration, a method that easily lends itself to generalization. Finally, we present the results from experimental tests that have been performed on a 5-RRR prototype., F. Thomas and J. M. Porta were partially supported by the Spanish Ministry of Economy and Competitiveness through projects DPI2017-88282-P and MDM-2016-0656. The support of Dr. Patrick Grosch in building the prototype is gratefully acknowledged.

The possibility to detect fast neutrons as a distinct signal from that one of γ-rays background is surely of great importance for several topics, spanning from homeland security to radiation monitoring in nuclear physics research plants. Nowadays, Helium-3 based detectors are extremely expensive, while the use of large volume liquid scintillators presents serious concerns related to spillage risks and waste disposal. A very attractive alternative is the use of commercially available solid scintillators, which exploits an aromatic polymer matrix entrapping very high loadings of primary dye, thereby enabling the use of pulse shape analysis (PSA) to discriminate between fast neutrons and γ-rays. In this work, we analyse in detail the optical features of a solid scintillator composed by polymethylphenylsiloxane (PMPS) as base polymer loaded with moderate amounts of 2,5-diphenyloxazole (PPO). Furthermore, fluorescence decay kinetics have been correlated to the observed pulse shape discrimination capabilities of this radiation and thermally resistant scintillator, whose performances have been discussed in terms of conformational features and excimers formation revealed by the optical analyses. The possibility to detect fast neutrons as a distinct signal from that one of γ-rays background is surely of great importance for several topics, spanning from homeland security to radiation monitoring in nuclear physics research plants. Nowadays, Helium-3 based detectors are extremely expensive, while the use of large volume liquid scintillators presents serious concerns related to spillage risks and waste disposal. A very attractive alternative is the use of commercially available solid scintillators, which exploits an aromatic polymer matrix entrapping very high loadings of primary dye, thereby enabling the use of pulse shape analysis (PSA) to discriminate between fast neutrons and γ-rays. In this work, we analyse in detail the optical features of a solid scintillator composed by polymethylphenylsiloxane (PMPS) as base polymer loaded with moderate amounts of 2,5-diphenyloxazole (PPO). Furthermore, fluorescence decay kinetics have been correlated to the observed pulse shape discrimination capabilities of this radiation and thermally resistant scintillator, whose performances have been discussed in terms of conformational features and excimers formation revealed by the optical analyses. ispartof: Scientific Reports vol:9 issue:1 pages:9154-9154 ispartof: location:England status: published

The study of the emitted particles, comparing pre-equilibrium and thermal components, is a useful tool to examine the nuclear structure of emitters. Possible clustering effects, which may change the expected decay chain probability, could be highlighted on the competition between different reaction mechanisms. The NUCL-EX collaboration (INFN, Italy) has carried out an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei. In this framework, the reactions 16O+30Si, 18O+28Si, 19F+27Al at 7 AMeV and 16O+30Si at 8 AMeV have been carried out using the GARFIELD+RCo array at Legnaro National Laboratories. Some anomalies in the α-particle emission channels have been evidenced in the measurement reported above, showing in an exclusive way the observed effects related to the entrance channels. The experimental results are compared to model prediction, for which the same filtering and complete event selection have been applied.

Four α-particles as a final state of 16O* quasi-projectile decayproduced in peripheral 16O+12C reactions at 130 MeV is thoroughly studied. The differentdecay channels leading to the four α-particles final state are reconstructed by carrying out an event-by-event analysis of α correlations in the population of intermediate 8Be and 12C. Although small, a non negligible contribution due to 8Begs evaporation is found.A comparison between predictions of an accurate Hauser-Feshbach decay code and branching ratios of the different decay channels is performed. Significant deviations are observed, among these the Hoyle state population which is considerably lower than the one predicted according to the statistical model, thus suggesting possible structure effects in the Coulomb barrier and/or in the transmission coefficients.

Synthesis of oleic acid stabilized ZnS nanocrystals activated with Mn is pursued. A hydrothermal method where high pressure and temperature are applied to control the nanocrystals growth is adopted. Capping the nanoparticle surface with oleic acid (OA) improved light output. Samples loaded with both the phosphor and the neutron sensitizer have been produced and tested in a preliminary test as alpha particle detectors and secondly as thermal neutron detectors. The results support further development for siloxane-based scintillator detectors employing ZnS (Mn) nanoparticles.

Measurements have been performed with scintillation crystals of LaBr3:Ce coupled to an array of Silicon Photomultipliers (SiPMs) in a 3 T magnetic field. The SiPMs were read out by digital data acquisition systems, including the GET electronics system. Inside of the B-field, energy resolution values of 3.82% FWHM at 661.7 keV are reported for a 1.5′′ cubic LaBr3:Ce crystal coupled to a 6 × 6 array of 6 × 6 mm2 SiPMs. No measurable degradation in energy resolution due to the presence of the strong magnetic field was observed.

The 32S(3He,d)33Cl one-proton transfer reaction is a powerful tool to investigate the spectroscopy of low-lying states in the proton-rich 33Cl nucleus. However, the extraction of firm differential cross-section data at various angles to benchmark and constrain theoretical models is made challenging by the presence of competitive reactions on target contaminants. In this paper we report on a recent measurement using a new generation hodoscope of silicon detectors, capable to detect and identify emitted deuterons down to energies of the order of 2 MeV. The high angular segmentation of our hodoscope combined with a suitable target to control possible contaminants, allowed to unambiguously disentangle the contribution of various states in 33Cl, in particular the 2.352 MeV state lying just few tens of keV above the proton separation energy.

Transfer reactions have always been of great importance for nuclear structure and reaction mechanism studies. So far, in multinucleon transfer studies, proton pickup channels have been completely identified in atomic and mass numbers at energies close to the Coulomb barrier only in few cases. We measured the multinucleon transfer reactions in the 40Ar+208Pb system near the Coulomb barrier, by employing the PRISMA magnetic spectrometer. By using the most neutron-rich stable 40Ar beam we could populate, besidesneutron pickup and proton stripping channels, also neutron stripping and proton pickup channels. Comparison ofcross sections between different systems with the 208Pb target and with projectiles going from neutron-poor to neutron-rich nuclei, as well as between the data and GRAZING calculations, was carried out.Finally, recent results concerning the measurement of the excitation function from the Coulomb barrier to far below for the 92Mo+54Fe system, where both proton stripping and pickup channels were populated with similar strength, will be discussed.

The work describes the development of a new class of liquid scintillators based on polysiloxane liquid compounds. These materials are characterized by low toxicity, chemical inertness, very low volatility and low flammability, allowing their use without concerns even at high temperatures in vacuum. In this view different polysiloxane based liquids have been tested, with variable content and distribution of phenyl lateral substituents and added with suitable dyes, namely 2,5-diphenyloxazole (PPO) and Lumogen Violet (LV). Absorption and fluorescence spectroscopy have been used in order to study the emission feature of the various compounds and to investigate the spectral matching between siloxane solvents and dissolved primary dyes. Scintillation efficiency towards 60Co and 137Cs gamma rays, relative to commercial liquid scintillator (EJ-309), has been measured and the results have been related to the energy transfer and energy migration mechanism from monomer and excimer forming sites in liquid siloxanes.

A new modular and high versatility hodoscope , OSCAR, has been developed and characterized. The aim of this hodoscope is to work as an ancillary detector of present large acceptance heavy ion detectors in specific angular regions where low thresholds and high granularities are needed. We discuss the capabilities of OSCAR in the Δ E–E identification of very low energy light particles, providing a precise map of the thickness uniformity of the Δ E (SSSSD, 20 μ m ) stage and showing how the thickness gradient affects the identification of particles. Energy spectra of light identified particles produced in Ca+Ca collisions at 35 AMeV are used to investigate isospin transport phenomena involving the emission of low energy particles from the quasi-target (QT) source in semi-peripheral nuclear collisions. The possibility to explore particle–particle correlations are also discussed.

The response of silicon-silicon-CsI(Tl) telescopes, developed within the FAZIA collaboration, to fragments produced in nuclear reactions 84 Krþ 120-124 Sn at 35 A MeV, has been used to study ion identification methods. Two techniques are considered for the identification of the nuclear products in the silicon stages. The standard DEE one requires signals induced in two detection layers by ions punching through the first one. Conversely, the digital Pulse Shape Analysis (PSA) allows the identification of ions stopped in the first silicon layer. The capabilities of these two identification methods have been compared for different mountings of the silicons, i.e. rear (particles entering through the low electric field side) or front (particles entering through the high electric field side) side injection. The DEE identification method gives exactly the same results in both configurations. At variance, the pulse shape discrimination is very sensitive to the detector mounting. In case of rear side injection, the identification with the ''energy vs. charge rise time'' PSA method presents energy thresholds which are significantly lower than in the case of front side injection. & 2012 Elsevier B.V. All rights reserved.

The study of nuclear cluster states bound by valence neutrons is a field of recent large interest. In particular, it is interesting to study the pre-formation of α-clusters in α-conjugate nuclei and the dynamical condensation of clusters during nuclear reactions. The NUCL-EX collaboration (INFN, Italy) is carrying out a research campaign studying preequilibrium emission of light charged particles and cluster properties of light and medium mass nuclei. For this purpose, a comparative study of the three nuclear reactions: O 16 + Si 30 , O 18 + Si 28 and F 19 + 27Al, has been recently carried out using the GARFIELD+RCo 4π setup. After a general introduction on the experimental campaign, the preliminary results for the three systems are presented.

International audience; The study of nuclear cluster states bound by valence neutrons is a field of recent large interest. In particular, it is important to study the pre-formation of α-clusters in α-conjugate nuclei and the dynamical condensation of clusters during nuclear reactions [1–5]. The NUCL–EX collaboration has recently initiated an experimental campaign of exclusive measurements of fusion–evaporation reactions with light nuclei as interacting partners. In collisions involving light systems, the low expected multiplicity of fragments increases the probability of achieving a quasi-complete reconstruction of the event. In particular the formation and decay modes of an excited 24Mg system have been studied through two different reactions, 12C (95 MeV)+ 12C and 14N (80.7 MeV)+ 10B, which have been used to produce fused systems with nearly the same mass and excitation energy (~60 MeV). In particular, even the de-excitation of the Hoyle state in 12C have been studied, both in peripheral (projectiles de-excitation) and in central collisions (six α-particles channel). Moreover, a research campaign studying pre-equilibrium emission of light charged particles and cluster properties of light and medium-mass nuclei has been carried out. For this purpose, a comparative study of the three nuclear systems 18O+28Si, 16O+30Si and 19F+27Al has been recently studied using the GARFIELD+RCo 4π setup [6]. The experimental data are compared with the predictions of simulated events generated with the statistical models (GEMINI++ and HFl) and through dynamical models like Stochastic Mean Field (SMF) and Antisymmetrized Molecular Dynamics (AMD) and filtered with a software replica of our apparatus in order to take into account the experimental conditions.

Pre-equilibrium emissions affect the production of excited systems in nuclear reactions, thus modifying their properties which enter as input parameters in the comparison with statistical models. In this contribution, we discuss this subject referring to recent results from experiments performed at Legnaro National Laboratories (Italy) with the GARFIELD apparatus complemented with other detectors. ispartof: Acta Physica Polonica B vol:48 issue:3 pages:635-639 ispartof: location:Zakopane: POLAND status: published

International audience; Clustering structural properties in medium-mass systems have been investigated studying the competition between the evaporation and pre-equilibrium particle emission in central collisions. At variance with light nuclei, in the case of heavier nuclei there are no experimental evidences of such structure effects, since the determination of pre-formed clusters within nuclear matter is less obvious.The two systems 16O + 65Cu and 19F + 62Ni, leading to the same compound system 81Rb*, have been studied at the same beam velocity (16 AMeV). The experiments have been performed using the GARFIELD + RCo multi-detection system at the Legnaro National Laboratories.Recent results of the data analysis and of the comparison of the experimental data with different statistical and dynamical model calculations are reported in this contribution.

Aiming at the fabrication of elastomeric organic scintillators for the detection of ionizing particles and neutrons with good light yield, mechanical robustness and radiation resistance, several samples of polysiloxane added with suitable amounts of fluorophores, such as 2,5-diphenyloxazole (PPO) and Lumogen Violet (LV), have been herein produced starting from either the copolymer polydiphenyldimethylsiloxane with 22 mol% of diphenyl groups or from blends of this precursor with different amounts of the homopolymer polymethylphenylsiloxane, thereby ultimately obtaining, after room temperature vulcanization (RTV), siloxane scintillators bearing different amounts of phenyl side groups. The scintillators have been characterized as for optical properties by excitation and fluorescence spectroscopy, while their performances as radiation detectors have been derived from light yield measurements upon irradiation with α particles. Ion beam-induced luminescence (IBIL) has been also applied using a proton beam of 2 MeV to compare the behavior of the different compositions by observing the in-situ degradation rate of the emitting species under ion irradiation. The samples and commercial scintillators (EJ-212 and EJ-200) used as a standard underwent heavy irradiation with γ-rays from a 60Co source at different doses, up to 54 kGy. Then, the ex-situ light yield toward α particles for each scintillator was collected twice again: immediately after the irradiation stage and after one month, in order to characterize the stability and the radiation hardness of scintillators produced with the different blends. © 2012 Elsevier B.V. All rights reserved.

Boron doped polysiloxane scintillators have been produced with different concentrations of boron and their scintillation yields have been studied as a function of the boron content under α, γ and fast and thermal neutrons irradiation. Their response has been compared with standard commercial plastic scintillators, namely EJ-212 as plastic scintillator and EJ-254 as boron doped scintillator. The produced samples exhibited a scintillation yield similar to EJ-212. The effect of boron on the energy transfer mechanism and on the polymer radiation hardness has been investigated by means of fluorescence and ion beam induced luminescence (IBIL) measurements. Detection efficiencies for thermal neutrons higher than commercial plastic scintillators have been attained with boron doped samples.

We present selected results recently obtained in the study of heavy ion transfer reactions at energies close to the Coulomb barrier by employing the large solid angle magnetic spectrometer PRISMA. We discuss the production of neutron-rich heavy nuclei via multinucleon transfer processes and the related effects of secondary processes, in particular nucleon evaporation, studied in a high resolution kinematic coincidence experiment. We also present the recent results in the studies of neutron-neutron correlations for closed shell and superfluid systems.

Polysiloxane-based scintillators are promising for employment in harsh environments, owing to their outstanding radiation resistance and thermal properties over the traditional plastics (polyvinyltoluene and polystyrene). In this work, cross-linked polydimethyl-co-diphenylsiloxane (PMPS) scintillators with 22% molar percentage of diphenylsiloxane units have been synthesised. 2,5-Diphenyloxazole and Lumogen Violet (BASF) were employed as primary and secondary fluor, respectively. Thermal neutrons sensitivity was achieved through the addition of 3% wt of ortho-carborane. Scintillation yield measurements were made by exciting with (241)Am alpha source samples with different concentrations of dye molecules. PMPS-based scintillators with ∼50% light yield as compared with the commercial plastic scintillator EJ212 were produced. The scintillation yield of the B-loaded samples under thermal neutrons was tested with a moderated Am-Be source and compared with the commercially available EJ254 (5% wt B). 2.2 MeV neutrons were produced by irradiating with a 4.0 MeV proton beam an LiF target, thus exploiting the reaction (7)Li(p,n)(7)Be. Time-of-flight measurements were performed to distinguish pulses due to neutrons or gamma. A similar test was performed with an EJ254 commercial scintillator for comparison. Using the same set-up, polyethylene bricks were used as a moderator to produce low-energy neutrons for testing B-loaded samples.

The radiation hardness of polysiloxane based scintillators has been measured by ion beam induced luminescence (IBIL). The light intensity as a function of the irradiation fluence with an He+ beam at 1.8 MeV (1.0 μA/cm2) has been measured on undoped polymers synthesized with different amounts of phenyl units and on polysiloxanes doped with two different dye molecules (BBOT and Lumogen Violet) sensitizing the scintillation yield.

Mass and charge identification of light charged particles detected with the 180 CsI(Tl) detectors of the GARFIELD apparatus is presented. A “tracking” method to automatically sample the Z and A ridges of “Fast–Slow” histograms is developed. An empirical analytic identification function is used to fit correlations between Fast and Slow, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products. A summary of the advantages of the proposed method with respect to “hand-based” procedures is reported.

Polysiloxane rubbers have been produced with different concentrations of phenyl groups and of dye molecules in order to find the best synthesis conditions for reaching a high light yield. In particular, two different polymer compositions were examined, namely with 15% and 22% of phenyl units in the starting resin. 2,5-Diphenyl oxazole (PPO) as a primary dopant and Lumogen F Violet 570 as secondary dopant were dispersed in the polysiloxane. Ion beam induced luminescence (IBIL) technique was employed for studying radioluminescence and radiation hardness properties. The α and γ scintillation yields were analyzed by measuring the pulse height spectra from 241Am and 60Co radioactive sources. First tests on the suitability of these materials to the detection of fast neutrons were also performed with a TOF procedure. Preliminary results indicate that these materials exhibit a scintillation yield comparable with NE102 plastic scintillator.

Polysiloxane based scintillators with high light yield have been synthesized. The polymer consists in cross-linked polydimethyl-co-diphenylsiloxane with different molar percentages of phenyl units. 2,5-diphenyl oxazole (PPO) and 2,5-bis(5-ter-butyl-2-benzoxazolyl)thiophene (BBOT) have been dispersed in the polymer as dopants. The energy transfer and scintillation capabilities have been investigated, for two different amounts of phenyl groups in the polymer network and for different concentrations of dye molecules, by means of fluorescence spectroscopy, ion beam induced luminescence (IBIL) and scintillation yield measurements with ? particles from an 241Am source. The luminescence features and the scintillation yields have been correlated to the composition of the scintillators.

The recently developed Cs2LiYCl6:Ce (CLYC) crystals are interesting scintillation detectors not only for their gamma energy resolution (

The time response of a recently developed polysiloxane based liquid scintillator has been analyzed for the first time: a special focus on the pulse shape discrimination capability of this material, which is characterized by low toxicity and low volatility, has been addressed. Fluorescence lifetime and scintillation pulses have been studied at different primary dye concentrations, with the aim of optimizing the neutron/gamma discrimination, connecting the results to the energy transfer and to the formation of excimers inside the scintillating solution. Pulse shape analysis performed during the irradiation of the samples with a pulsed neutron beam allowed the definition of a figure of merit as an indicative parameter for the neutron/gamma discrimination. The dependence of this parameter from radiation energy and PPO concentration has been analyzed in order to optimize the performances of the material in view of its possible use in environments with high gamma-ray radiation background.

A Single-crystal Diamond (SD) detector prototype was installed at Joint European Torus (JET) in 2013 and the achieved results have shown its spectroscopic capability of measuring 2.5 MeV neutrons from deuterium plasmas. This paper presents measurements of the SD response function to monoenergetic neutrons, which is a key point for the development of a neutron spectrometer based on SDs and compares them with Monte Carlo simulations. The analysis procedure allows for a good reconstruction of the experimental results. The good pulse height energy resolution (equivalent FWHM of 80 keV at 2.5 MeV), gain stability, insensitivity to magnetic field, and compact size make SDs attractive as compact neutron spectrometers of high flux deuterium plasmas, such as for instance those needed for the ITER neutron camera. ispartof: Review of Scientific Instruments vol:87 issue:11 ispartof: location:Madison: WI status: published

The application range of neutron detectors covers many topics, not only involving experimental research, but spanning tens of industrial, health, transport, cultural heritage fields of interest. Several studies focus on new scintillating materials where the light response, under fast and slow neutrons exposure, is triggered by proton recoil or by the presence of neutron capture materials as 10B, 6Li or 157Gd. Neutron monitors, where the robustness of silicon-based detectors can be fully exploited by coupling with suitable neutron absorber/converter materials, have recently proved their outstanding performances. Discrimination between neutron signals from other radiations, such as $ \gamma$ - or cosmic rays, is achieved through timing techniques or with pulse shape analysis. Furthermore, the choice of the detection/discrimination techniques depends on the type of application the detector will be used for. An example is Radiation Portal Monitors (RPM) for cargo inspection or luggage control that are required to satisfy specific international standards for $ \gamma$ and neutron detection efficiencies. This paper is an overview of some of the National Institute of Nuclear Physics (INFN) activities in the field of neutron detection, involving novel technologies. We will describe the most recent advances related to scintillators and silicon-based detectors coupled with thin films of suitable converters for neutron detection and we will discuss applications in the field of nuclear security.

The observation of $^{26}$Al gives us the proof of active nucleosynthesis in the Milky Way. However the identification of the main producers of $^{26}$Al is still a matter of debate. Many sites have been proposed, but our poor knowledge of the nuclear processes involved introduces high uncertainties. In particular, the limited accuracy on the $^{25}$Mg($\alpha$,n)$^{28}$Si reaction cross section has been identified as the main source of nuclear uncertainty in the production of $^{26}$Al in C/Ne explosive burning in massive stars, which has been suggested to be the main source of $^{26}$Al in the Galaxy. We studied this reaction through neutron spectroscopy at the CN Van de Graaff accelerator of the Legnaro National Laboratories. Thanks to this technique we are able to discriminate the ($\alpha$,n) events from possible contamination arising from parasitic reactions. In particular, we measured the neutron angular distributions at 5 different beam energies (between 3 and 5 MeV) in the \ang{17.5}-\ang{106} laboratory system angular range. The presented results disagree with the assumptions introduced in the analysis of a previous experiment., Comment: 9 pages, 9 figures - accepted by EPJA

"Beta Beams" produce collimated pure electron (anti-) neutrino beams by accelerating beta active ions to high energies and having them decay in a race track shaped storage ring of 7 km circumference, the Decay Ring. EUROnu Beta Beams are based on CERN infrastructures and existing machines. Using existing machines may be an advantage for the cost evaluation, however, this choice is also constraining the Beta Beams. The isotope pair of choice for the Beta Beam is 6He and 18Ne. However before the EUROnu studies one of the needed isotopes, 18Ne, could not be produced in rates that satisfy the needs for physics reach of the Beta Beam. Therefore, studies of alternative beta emitters, 8Li and 8B, with properties interesting for a Beta Beam have been proposed and have been studied within EUROnu. These alternative isotopes could be produced by using a small storage ring, in which the beam traverses a target, creating the 8Li and 8B isotopes. This Production Ring, the injection Linac and the target system have been evaluated. Measurements of the cross-section of the reactions to produce the Beta Beam isotopes show interesting results. A device to collect the produced isotopes from the target has been developed and tested. However, the obtained rates of the 8Li and 8B, using the Production Ring for production of 8Li and 8B, is not yet, according to simulations, giving the rates of isotopes that would be needed. Therefore, a new method of producing the 18Ne isotope has been developed and tested giving good production rates. The baseline presented for the Beta Beam is therefore now to use the 6He and 18Ne isotopes for neutrino production. A 60 GHz ECRIS prototype, the first in the world, was developed and tested with contributions from EUROnu. The Beta Beam has to take into account the modifications of the injectors planned in view of LHC-upgrades. The Decay Ring lattices for the 8Li and 8B have been developed, the lattice for 6He and 18Ne has been optimized also to ensure the high intensity ion beam stability.

The goal of the FAZIA Collaboration is the design of a new-generation 4π detector array for heavy-ion collisions with radioactive beams. This article summarizes the main results of the R&D phase, devoted to the search for significant improvements of the techniques for charge and mass identification of reaction products. This was obtained by means of a systematic study of the basic detection module, consisting of two transmission-mounted silicon detectors followed by a CsI(Tl) scintillator. Significant improvements in ΔE-E and pulse-shape techniques were obtained by controlling the doping homogeneity and the cutting angles of silicon and by putting severe constraints on thickness uniformity. Purposely designed digital electronics contributed to identification quality. The issue of possible degradation related to radiation damage of silicon was also addressed. The experimental activity was accompanied by studies on the physics governing signal evolution in silicon. The good identification quality obtained with the prototypes during the R&D phase, allowed us to investigate also some aspects of isospin physics, namely isospin transport and odd-even staggering. Now, after the conclusion of the R&D period, the FAZIA Collaboration has entered the demonstrator phase, with the aim of verifying the applicability of the devised solutions for the realization of a larger-scale experimental set-up.

The detection of the 1809 keV emission line associated with the decay of 26 Al in the interstellar medium provides a direct evidence of recent nucleosynthesis events in our galaxy. 26 Al is thought to be mainly produced in massive stars, but in order to have a quantita- tive understanding of the 26 Al distribution, the cross section of all the nuclear reactions involved in its production should be accurately known. A recent sensitivity study demonstrated that the 25 Mg( ,n) 28 Si is the reaction with the strongest impact on the synthesis of 26 Al during explosive Neon and Carbon burning (4). In order to improve the experimental knowledge of the 25 Mg( ,n) 28 Si cross section, a new direct measurement has been performed at Legnaro National Laboratories. The experimental setup, the data analysis and preliminary results are discussed.

Neutron detectors are extensively used at many nuclear research facilities across Europe. Their application range covers many topics in basic and applied nuclear research: in nuclear structure and reaction dynamics (reaction reconstruction and decay studies); in nuclear astrophysics (neutron emission probabilities); in nuclear technology (nuclear data measurements and in-core/off-core monitors); in nuclear medicine (radiation monitors, dosimeters); in materials science (neutron imaging techniques); in homeland security applications (fissile materials investigation and cargo inspection). Liquid scintillators, widely used at present, have however some drawbacks given by toxicity, flammability, volatility and sensitivity to oxygen that limit their duration and quality. Even plastic scintillators are not satisfactory because they have low radiation hardness and low thermal stability. Moreover organic solvents may affect their optical properties due to crazing. In order to overcome these problems, phenyl-polysiloxane based scintillators have been recently developed at Legnaro National Laboratory. This new solution showed very good chemical and thermal stability and high radiation hardness. The results on the different samples performance will be presented, paying special attention to a characterization comparison between synthesized phenyl containing polysiloxane resins where a Pt catalyst has been used and a scintillating material obtained by condensation reaction, where tin based compounds are used as catalysts. Different structural arrangements as a result of different substituents on the main chain have been investigated by High Resolution X-Ray Diffraction, while the effect of improved optical transmittance on the scintillation yield has been elucidated by a combination of excitation/fluorescence measurements and scintillation yield under exposure to alpha and \(\upgamma \)-rays.

We report on the first prototypes of hybrid detectors for neutrons from the INFN HYDE project. Devices consist of 3D silicon sensors coupled to PolySiloxane-based converters. The sensor design and fabrication technology are presented, along with initial results from the functional characterization of the devices in response to radioactive sources and neutron beams of different energies.

An upgraded GARFIELD + Ring Counter (RCo) apparatus is presented with improved performances as far as electronics and detectors are concerned. On one side fast sampling digital read out has been extended to all detectors, allowing for an important simplification of the signal processing chain together with an enriched extracted information. On the other side a relevant improvement has been made in the forward part of the setup (RCo): an increased granularity of the CsI(Tl) crystals and a higher homogeneity in the silicon detector resistivity. The renewed performances of the GARFIELD + RCo array make it suitable for nuclear reaction measurements both with stable and with Radioactive Ion Beams (RIB), like the ones foreseen for the SPES facility, where the Physics of Isospin can be studied., Comment: 13 pages, 19 figures - paper submitted to Eur. Phys. J. A

The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams., 8 pages, 2 figures, Contribution to conference proceedings of the 25th International Nuclear Physics Conference (INPC 2013) Journal-ref: 25th International Nuclear Physics Conference (INPC 2013), Firenze : Italy (2013)

Dissipative 12C+12C reactions at 95 MeV are fully detected in charge with the GARFIELD and RCo apparatuses at LNL. A comparison to a dedicated Hauser-Feshbach calculation allows to select events which correspond, to a large extent, to the statistical evaporation of highly excited 24Mg, as well as to extract information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain. Residual deviations from a statistical behaviour are observed in \alpha yields and attributed to the persistence of cluster correlations well above the 24Mg threshold for 6 \alpha's decay.

Isospin mixing in the hot compound nucleus ${}^{80}$Zr was studied by measuring and comparing the $\ensuremath{\gamma}$-ray emission from the fusion reactions ${}^{40}\text{Ca}+{}^{40}\text{Ca}$ at ${E}_{\text{beam}}=200$ MeV and ${}^{37}\text{Cl}+{}^{44}\text{Ca}$ at ${E}_{\text{beam}}=153$ MeV. The $\ensuremath{\gamma}$ yield associated with the giant dipole resonance is found to be different in the two reactions because, in self-conjugate nuclei, the E1 selection rules forbid the decay between states with isospin $I=0$. The degree of mixing is deduced from statistical-model analysis of the $\ensuremath{\gamma}$-ray spectrum emitted by the compound nucleus ${}^{80}$Zr with the standard parameters deduced from the $\ensuremath{\gamma}$ decay of the nucleus ${}^{81}$Rb. The results are used to deduce the zero-temperature value, which is then compared with the latest predictions. The Coulomb spreading width is found to be independent of temperature.

International audience; The reactions 32S+58,64Ni are studied at 14.5 A MeV. Evidence is found for odd-even effects in isotopic observables of the decay of a projectile-like source. The influence of secondary decays on the staggering is studied with a correlation function technique, showing that odd-even effects are due to interplay between pairing effects in the nuclear masses and in the level densities.