The article describes the main achievements of the NUMEN project together with an updated and detailed overview of the related R&D activities and theoretical developments. NUMEN proposes an innovative technique to access the nuclear matrix elements entering the expression of the lifetime of the double beta decay by cross section measurements of heavy-ion induced Double Charge Exchange (DCE) reactions. Despite the two processes, namely neutrinoless double beta decay and DCE reactions, are triggered by the weak and strong interaction respectively, important analogies are suggested. The basic point is the coincidence of the initial and final state many-body wave-functions in the two types of processes and the formal similarity of the transition operators. First experimental results obtained at the INFN-LNS laboratory for the 40 Ca( 18 O, 18 Ne) 40 Ar reaction at 270 MeV, give encouraging indication on the capability of the proposed technique to access relevant quantitative information.The two major aspects for this project are the K800 Superconducting Cyclotron and MAGNEX spectrometer. The former is used for the acceleration of the required high resolution and low emittance heavy ion beams and the latter is the large acceptance magnetic spectrometer for the detection of the ejectiles. The use of the high-order trajectory reconstruction technique, implemented in MAGNEX, allows to reach the experimental resolution and sensitivity required for the accurate measurement of the DCE cross sections at forward angles. However, the tiny values of such cross sections and the resolution requirements demand beam intensities much larger than manageable with the present facility. The on-going upgrade of the INFN-LNS facilities in this perspective is part of the NUMEN project and will be discussed in the article.3

Silicon carbide (SiC) is a compound semiconductor, which is considered as a possible alternative to silicon for particles and photons detection. Its characteristics make it very promising for the next generation of nuclear and particle physics experiments at high beam luminosity. Silicon Carbide detectors for Intense Luminosity Investigations and Applications (SiCILIA) is a project starting as a collaboration between the Italian National Institute of Nuclear Physics (INFN) and IMM-CNR, aiming at the realization of innovative detection systems based on SiC. In this paper, we discuss the main features of silicon carbide as a material and its potential application in the field of particles and photons detectors, the project structure and the strategies used for the prototype realization, and the first results concerning prototype production and their performance.

Abstract:In this paper, we present the status of the line for laser-driven light ions acceleration (L3IA) currently under implementation at the Intense Laser Irradiation Laboratory (ILIL), and we provide an overview of the pilot experimental activity on laser-driven ion acceleration carried out in support of the design of the line. A description of the main components is given, including the laser, the beam transport line, the interaction chamber, and the diagnostics. A review of the main results obtained so far during the pilot experimental activity is also reported, including details of the laser-plasma interaction and ion beam characterization. A brief description of the preliminary results of a dedicated numerical modeling is also provided.

PoS(BORMIO2017)015NURE: An ERC project to study nuclear reactions for neutrinoless double beta decay M. Cavallaro 2 Neutrinoless double beta decay (0νββ) is considered the best potential resource to determine the absolute neutrino mass scale. Moreover, if observed, it will signal that the total lepton number is not conserved and neutrinos are their own anti-particles. Presently, this physics case is one of the most important research "beyond Standard Model" and might guide the way towards a Grand Unified Theory of fundamental interactions.Since the ββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. The 0νββ decay rate can be expressed as a product of independent factors: the phase-space factors, the nuclear matrix elements (NME) and a function of the masses of the neutrino species. Thus the knowledge of the NME can give information on the neutrino mass scale, if the 0νββ decay rate is measured.In the NURE project, supported by a Starting Grant of the European Research Council, nuclear reactions of double charge-exchange (DCE) will be used as a tool to extract information on the ββ NME. In DCE reactions and ββ decay, the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute crosssections can give crucial information on ββ matrix elements. IntroductionDouble charge-exchange reactions (DCE) are processes characterized by the transfer of two units of the isospin component (two protons transformed into two neutrons or vice versa), leaving the mass number unchanged. The initial and final nuclear states involved in DCE reaction and ββ decay are the same and the transfer operators have similar spin-isospin mathematical structure. Namely they both contain a Fermi, a Gamow-Teller and a rank-two tensor term. A relevant amount of linear momentum (of the order of 100 MeV/c) is available in the virtual intermediate channel in both processes. This is a crucial similarity since the nuclear matrix elements strongly depend on the momentum transfer and other processes (single charge-exchange reactions, 2νββ decay etc.) cannot probe this feature. Thus, even if the two processes are mediated by different interactions, the involved nuclear matrix elements could be connected and the determination of the DCE reaction cross-sections could give important information on the ββ matrix elements.One should remind that a proportionality relation is well established at a level of few percent between single β decay strengths and single charge-exchange reaction cross-sections, under specific dynamical conditions. Indeed, single charge-exchange reactions are routinely used as a tool to determine Fermi and Gamow-Teller transition strengths for single β decay, as demonstrated by several works [1][2][3][4][5][6][7]. However, studying the link between ββ-decay strengths and DCE crosssections is a not trivial task and requires a strong effort.Experimental attempts were done in the past to perform DCE reactions [8], [9]. Howeve...

No abstract

In this contribution, we will illustrate the main results of the R&D activities related to the Silicon Carbide detectors associated with NU-MEN project. NUMEN PhysicsThe NUMEN project [1][2][3][4] proposes an innovative technique to access the nuclear matrix elements entering the expression of the half-life of the double beta decay by relevant cross sections measurements of heavy-ion induced double charge exchange (DCE) reactions, ( 18 O, 18 Ne), ( 20 Ne, 20 O) and ( 12 C, 12 Be). DCE reactions will be investigated at the INFN-LNS laboratory with incident energies ranging from 10 to 60 MeV/A. A key aspect of the project is the use of the MAGNEX [5-6] large acceptance magnetic spectrometer to detect the ejectiles produced in the nuclear collisions [7]. With

Background: Double Charge Exchange (DCE) nuclear reactions have recently attracted much interest as tools to provide experimentally driven information about the Nuclear Matrix Elements of interest in the context of neutrino-less double beta decay. In this framework a good description of the reaction mechanism and a complete knowledge of the initial and final state interactions is mandatory. Presently, not enough is known about the details of the optical potentials and nuclear response to isospin operators for many of the projectile-target systems proposed for future DCE studies. Among these, 20 Ne + 76 Ge DCE reaction is particularly relevant due to its connection with 76 Ge double beta decay. Purpose: Characterization of the initial state interaction for the 20 Ne + 76 Ge reactions at 306 MeV bombarding energy: determination of the optical potential and exploration of the role of the couplings between elastic channel and inelastic transitions to the first low-lying excited states. Methods: Determination of the experimental elastic and inelastic scattering cross section angular distributions. Comparison of the theoretical predictions adopting different models of optical potentials with the experimental data. Evaluation of the coupling effect through the comparison of the Distorted Wave Born Approximation calculations with the Coupled Channels ones. Results: Optical Models fail in the description of the elastic angular distribution above the grazing angle (∼ 9.4 • ). A correction in the geometry to effectively account for deformation of the involved nuclear systems improves the agreement up to about 14 • . Coupled channels effects are crucial to obtain a good agreement at large angles in the elastic scattering cross section. Conclusions: The analysis of elastic and inelastic scattering data turned out to be a powerful tool to explore the initial and final state interaction in heavy ion nuclear reactions also at high transferred momenta. * Electronic address: alessandro.spatafora@lns.infn.it † Electronic address: cappuzzello@lns.infn.it

In this work we present the response of a new large volume 4H Silicon Carbide (SiC) detector to 14 MeV neutrons. The device has an active thickness of 100 μm (obtained by epitaxial growing) and an active area of 25 mm 2 . Tests were conducted at the ENEA-Frascati Neutron Generator facility by using 14.1 MeV neutrons. The SiC detector performance was compared to that of Single-Crystal Diamond (SCD) detectors. The SiC response function was successfully measured and revealed a very complex structure due to the presence in the detector of both Silicon and Carbon atoms. Nevertheless, the flexibility in the SiC manufacturing and the new achievements in terms of relatively large areas (up 1x1 cm 2 ) and a wide range of thicknesses makes them an interesting alternative to diamond detectors in environments where limited space and high neutron fluxes are an issue, i.e. modern neutron cameras or in-vessel tokamak measurements for the new generation fusion machines such as ITER. The absence of instabilities during neutron irradiation and the capability to withstand high neutron fluences and to follow the neutron yield suggest a straightforward use of these detectors as a neutron diagnostics.