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The ASY-EOS experiment at GSI laboratory measured the direct and elliptic flow of neutrons and light charged particles in the reaction 197Au+197 Au at 400 A MeV incident energy. The ratio of elliptic flow of neutrons with respect to that of the light charged particles was used as main experimental observable to probe the density dependence of the symmetry energy term of the nuclear equation of state. Results, obtained by comparison of the experimental data with the UrQMD model predictions, strongly support a moderately soft to linear density dependence of the symmetry energy at suprasaturation densities below 2ρ0.

Two and multi particle correlations from the decay of sources produced in 12C+24Mg and 12C+208Pb collisions at E=35 AMeV have been studied by using the forward part (1° < θlab < 30°) of the CHIMERA multi-detector. Correlations and invariant mass spectroscopy are used to explore simultaneous and sequential decays of resonances in light isotopes with Z∼3-6, produced in peripheral collisions via the break-up of excited quasi-projectiles. Among them we mention 5Li, 6Li, 6Be, 8Be and the astrophysically important state in 12C decaying into three alpha particles. Results and future perspectives at the INFN-LNS will be presented.

The experimental investigation of Heavy Ion reactions at Fermi energies requires an accurate measurement of observables, such as linear momentum and energy of the detected particles. In order to address this problem, dedicated and flexible correlator arrays are useful tools to be coupled with 4π detectors. One of these arrays is FARCOS, presently under construction at the INFN Sezione di Catania and Laboratori Nazionali del Sud (LNS).

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data.

The binary break-up of projectile-like fragments in non central heavy-ion collisions follows different decay patterns, from equilibrated emission towards dynamical (prompt) fission. Recently, comparing two systems with different N/Z in the entrance channel, it has been shown that the dynamical emission cross-section is enhanced for the most neutron rich system while the statistical emission cross-section is independent from the isotopic composition. In order to understand this dependence and disentangle it from the initial size of the nuclei, we have studied the two isobaric systems 124Xe+64 Zn and 124Xe+64 Ni at 35 A MeV (InKiIsSy experiment), in comparison with the previous studied reactions (124Sn +64 Ni and 112Sn +58 Ni) at the same bombarding energy. We present the first results evidencing a striking similar effect in the dynamical decay as a function of the N/Z of the target for equal size systems.

Projectile break-up reactions induced on polyethylene (CH2) target are used in order to study the spectroscopy of 10Be and 16C nuclei. For the present experiment we used 10Be and 16C beams delivered by the FRIBs facility at INFN-LNS, and the CHIMERA 4π multi-detector. 10Be and 16C structures are studied via a relative energy analysis of break-up fragments. The 4He+6He break-up channel allowed us to study the spectroscopy of 10Be; in particular we find evidence of a new state in 10Be at 13.5 MeV excitation energy. The 16C nucleus is studied via 6He-10Be correlation; we find the fingerprint of a possible state at about 20.6 MeV

Introduction: Invasive techniques for objectively measuring intracranial pressure (ICP) pose significant risks including infection, intracerebral hemorrhage, and brain injury (Maniker et al., 2006; Wolfe and Torbey, 2009; Scheithauer et al., 2009). Otoacoustic emissions (OAEs) provide non-invasive indicators of ICP changes, as the OAE phase reflects middle ear transmission, which is influenced by ICP via its connection to intracochlear pressure. A calibration of the technique is based on the ICP and OAE phase data collected by Buki et al. (1996) in patients undergoing controlled ICP changes during neurosurgery. Forward pressure level (FPL) calibration provides additional insight into middle ear transmission, complementing and validating OAE phase measurements. Material and methods: Five International Space Station (ISS) normal-hearing astronauts were tested for distortion product otoacoustic emissions (DPOAEs) pre-flight, in microgravi-ty in-flight conditions, and post-flight. Ground experiments were conducted involving 20 young volunteers, who were DPOAE tested in different body postures. The DPOAE response was time-frequency filtered (Moleti et al., 2012) to unmix the distortion and reflection components. The FPL calibration data provided, as a byproduct, a direct estimate of the load impedance measured in the ear canal, which is related to the middle ear reflectance. Results: Systematic changes associated with microgravity and postural changes were observed for all considered physical quantities, with the DPOAE phase generally yielding the best results. Although physical quantities such as reflectance and load impedance are more directly related to ICP changes than the OAE phase, their numerical evaluation may be more difficult, because it involves ratios between complex quantities that are very sensitive to phase uncertainties. Conclusions: DPOAE measurements with FPL calibration and component unmixing provide effective non-invasive indicators of ICP changes. Future research directions include applications in Glaucoma patients and absolute calibration in neural surgery environments for several types of clinical population such as hydrocephalus and intracranial tumor. [ABSTRACT FROM AUTHOR]

Relatively large yields of various exotic beams produced through in-flight fragmentation are available at LNS. Using the CHIMERA detector, we performed various experiments to study elastic and inelastic scattering, transfer, break-up, and reaction dynamics with targets from proton and deuteron to carbon and heavier. For reactions with relatively light systems we used the kinematical coincidence method to extract high resolution angular distributions of binary reactions from the measured light particle energy spectra. We also used the CsI detectors of CHIMERA to detect gamma rays emitted in the reactions. Some of most recent results are presented together with future perspectives with the coupling of CHIMERA with FARCOS array.

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au, 96Zr+96Zr and 96Ru+96Ru collisions at 400 MeV/nucleon with the Large Area Neutron Detector LAND as part of a setup with several additional detection systems used for the event characterization. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data.

The systems 124Sn+64Ni and 112Sn+58Ni at 35 AMeV were analyzed in previous experiments, by using the 4π multi-detector CHIMERA in order to investigate the time-scale and mechanisms of fragments formation. By comparing the two systems, effects that have been correlated to Isospin transport in reaction dynamics and symmetry energy term of nuclear equation of state at sub-saturation density were found. Recently, in order to disentangle the Isospin effects from size effects the 124Xe+64Ni reaction was investigated at the same beam energy of 35 AMeV.

Nuclear matter under extreme conditions can be studied in the laboratory with heavy-ion collisions. In this case one can indeed vary the incident energy and explore different impact parameter and rapidity regions to access densities that extend above and below saturation. This opportunity allows one to learn about the nuclear equation of state and its implications in astrophysics phenomena such as supernovae explosions and neutron stars properties. All these phenomena involve time scales that need to be accessed with two- and multi-particle correlation measurements. In this contribution a brief report of the FARCOS array will be presented. In particular, tests with alpha sources and beams and preliminary results from a recent experiment INKIISSY performed using a FARCOS prototype made of four telescopes will be presented.

Accessing dynamics in heavy-ion collisions represents a priority in nuclear physics, due to its links to the isospin dependence of the nuclear Equation of State and the space-time properties of systems under extreme conditions produced during the reaction. By means of particle-particle correlations it is possible to probe such space-time properties, allowing one to learn about the space-time properties of the source of particle emission. In this poster presentation we show an application of imaging techniques to study the two-proton source function at the dynamical stage of the reaction.

Semi-peripheral collisions of 64Ni + 124Sn in direct and inverse kinematics, at 35 A MeV incident energy, are studied to characterize the dynamical origin and align-ments properties of fragments emission at midrapidity. This emission is partly due to the fragmentation of a transient neck joining the projectile and target in the early stages of the reaction. Recently we exploited observable from neck fragmentation to constraint the density dependence of the symmetry energy. In this contribution we focus on the density evolution of the mid-rapidity source. An experimental survey is suggested to check if data are consistent with the formation of neck fragments in a dilute density region in contact with the projectile-like and target-like spectators at normal saturation density.

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy-ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. The results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model simulations favoured a moderately soft symmetry term, but suffer from a considerable statistical uncertainty. These results have been confirmed by an independent analysis based on the Tübingen QMD simulations. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration. The present status of the data analysis is reported

The construction of a new array to study femtoscopy and multi-particle correlations in heavy ion collisions at intermediate energies (E=20-1000 AMeV) has been started at the INFN. The project, named FARCOS (Femtoscope ARray for COrrelations and Spectroscopy) is aimed at developing of a detection system with high pixelation capabilities in order to perform precision measurements of particle correlations for nuclear dynamics and spectroscopy. We present first detection simulations for FARCOS and first results related to the commissioning of CsI(T1) crystals, an important detection stage of each telescope.

The elliptic-flow ratio of neutrons with respect to protons in reactions of neutron rich Heavy-Ion at intermediate energies has been recently proposed as an observable sensitive to the strength of the symmetry term in the nuclear equation of state (EOS) at supra-saturation densities. The recent results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate of the symmetry term of the EOS but suffer from a considerable statistical uncertainty. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration in May 2011.

Correlations between two or more particles can be used as a tool to explore the space-time features of nuclear reactions as well as spectroscopic properties of produced unbound clusters. In order to have new options to study the mentioned correlations, FARCOS (Femtoscope ARray for COrrelations and Spectroscopy) has been conceived as a compact high resolution array, composed of square telescopes. In this work the main features of FARCOS array as well as part of the physics cases are described.

The recent intensity upgrade of the LNS fragmentation beam is discussed. The available beams, the tagging procedures and details on the beam quality are reported. The experimental program started with the CHIMERA detector using such beams is also discussed with preliminary results and future perspectives.

Effects related to the neutron to proton ratio (N/Z) degree of freedom in 40,48Ca+40,48Ca reactions at 25 MeV/nucleon have been investigated. Isotopic effect and even-odd staggering characterize the emission of light fragments at forward angles. The study of isobaric ratio 7Li/7Be for quasi-projectile source in semi-peripheral event of reactions allows moreover to investigate isospin diffusion effects in heavy ion collisions.

We will discuss results concerning the fate of hot nuclear systems populated in 40,48Ca+40,48Ca reactions at 25 MeV/nucleon. Due to the complexity of events, we used the Chimera 4π device as detection system. By selecting central events of reaction, we found that the interplay between binary-like and evaporation residue emissions is strongly sensitive on the N/Z of the entrance channels. In particular, evaporation residue emission increases at increasing the neutron content of colliding system. By comparing or data with CoMD-II model calculations, we can extract information about the density depend part of Symmetry Potential in the Nuclear Equation of State at near-saturation densities.