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A 10Be beam having intensities up to 3 enA has been accelerated at the Tandem of the Laboratori Nazionali del Sud in Catania. The used 10Be was chemically extracted from a proton irradiated graphite target used for muon production at the Paul Scherrer Institute. In order to maximise the extracted current using a minimum amount of isotope, several preparatory tests, needed to optimise the preparation of the Tandem sputter source cathodes, were performed. The acceleration tests and accelerated beam characteristics will be discussed and examples of beam use for nuclear structure investigations will be presented.

In the framework of the MICADO (Measurement and Instrumentation for Cleaning And Decommissioning Operations) European Union (EU) project, aimed at the full digitization of low- and intermediate-level radioactive waste management, a set of 32 solid state thermal neutron detectors named SiLiF has been built and characterized. MICADO encompasses a complete active and passive characterization of the radwaste drums with neutrons and gamma rays, followed by a longer-term monitoring phase. The SiLiF detectors are suitable for the monitoring of nuclear materials and can be used around radioactive waste drums possibly containing small quantities of actinides, as well as around spent fuel casks in interim storage or during transportation. Suitable polyethylene moderators can be exploited to better shape the detector response to the expected neutron spectrum, according to Monte Carlo simulations that were performed. These detectors were extensively tested with an AmBe neutron source, and the results show a quite uniform and reproducible behavior.

The worldwide need to replace 3He for the neutron detection has triggered R&D on new technologies and methods. A promising one is based on commercial solid state silicon detectors coupled with thin neutron converter layers containing 6Li. After proving the feasibility of this technique, we characterized the behavior of such a detector with different converter layer thicknesses. In this paper we also disentangle other contributions to the overall spectrum shape observed with this kind of detector, proving that its detection efficiency can be made reasonably high and that the gamma/neutron discrimination capability is comparable to the one of 3He tubes., Submitted to Nuclear Instruments and Methods in Physics Research, section A

In the framework of the MICADO (Measurement and Instrumentation for Cleaning And Decommissioning Operations) European Union (EU) project, aimed at the full digitization of low and intermediate-level radioactive waste (radwaste) management, a set of 32 solid state thermal neutron detectors, named SiLiF, and 36 gamma-ray counters based on a scintillating fiber readout at each end by a silicon photomultiplier, named SciFi, have been built and characterized. MICADO project encompasses a complete active and passive characterization of the radwaste drums with neutrons and gamma rays, followed by a longer-term monitoring phase. The detectors described are suitable for the monitoring of nuclear materials and can be used around radioactive waste drums possibly containing small quantities of actinides, as well as around spent fuel casks in interim storage or during transportation. Suitable polyethylene moderators, for the SiLiF detectors, can be exploited to better shape the detector response to the expected neutron spectrum, according to Monte Carlo simulations that were performed. The SciFi detectors were thoroughly tested with a 22Na and a 137Cs gamma-ray sources. Both detectors described were tested with an intense AmBe source of neutron and gamma ray. The results are satisfactory and show a quite uniform and reproducible behavior. The next step will be the test in a real environment.

Introduction Sleep is an important element of health that can impact daytime performance in brain injury rehabilitation. Actigraphy in a pediatric inpatient setting can pose challenges when there are increased amounts of time spent in a hospital bed. A rest-activity ratio (Duclos et al., 2013) has demonstrated utility in adult brain injury populations, showing sensitivity to improved regulation of the sleep-wake cycle as individuals recover during their hospitalization. The present study sought to examine the utility of this ratio in differentiating children with and without acquired brain injury (ABI). Methods Sixteen individuals, ages 8-16 (M=12.6, SD=2.4) admitted to an inpatient pediatric rehabilitation hospital wore an actigraph over a 7-day period. Eight inpatients were being treated for ABI whereas another 8 inpatients treated for other, non-neurological conditions served as a control. Raw activity counts across the 24-hour period were analyzed to derive a rest-activity ratio. Results Those with ABI had lower average ratios (0.73) compared with patients without ABI (0.84), F(1,14)=4.3, p=0.058. Individuals with ratios of 0.85 or higher were rated by their physical therapists as being more alert during therapy using a 5-point Likert scale, F(1,14)=4.1, p=0.061. While these results were marginally significant, this pilot sample was small, and the effect sizes were large (eta squared = 0.234 and 0.229 respectively). Conclusion The rest-activity ratio successfully distinguished those with ABI from a non-ABI sample. This preliminary evidence in a pediatric sample suggests that this ratio, shown to be sensitive to the effects of brain injury on sleep-wake regulation, may be a useful metric in the inpatient pediatric rehabilitation setting when sleep diaries may be difficult to obtain and patients may be spending more time in bed while awake. Future studies with larger sample sizes are needed to explore the correlates of this ratio with other aspects of rehabilitation after pediatric brain injury. Support This study was funded in part through a generous grant from the Church & Dwight Employee Giving Fund

6 pags., 5 figs. -- 12th International Spring Seminar on Nuclear Physics, IOP Conf. Series. -- Open Access funded by Creative Commons Atribution Licence 3.0, In order to investigate the existence of molecular and/or exotic cluster configurations in Boron and Carbon n-rich isotopes we undertook two experiments: the first experimental study of exotic 9Li+¿ cluster states in 13B using the resonance scattering method at TRIUMF (Canada), and, with the same technique, the measurement of 10Be+¿ scattering at LNS in Catania, where a 10Be radioactive beam was produced for the first time. In order to measure the excitation function in a wide energy range, the beams were stopped in a Helium-flooded chamber. In the case of 13B, the elastic excitation function shows the presence of various peaks in an excitation energy region never explored before. In the case of 14C, our exclusive measurement of elastic scattering data with a high intensity beam, sheds some light on the contradictory previously published results [1, 2].

The Silicon Photomultiplier (SiPM) has become a solid playground for many applications requiring compact and well performing photon detectors. In particular, this is true when the detection of few photons with good time resolution is required. In this paper, we show how the SiPM features can be exploited to set up a compact neutron detector. By coupling two SiPMs to an inorganic scintillator strip, one can discriminate between gamma-rays and neutrons and, at the same time, determine the impact position with millimeter accuracy.

In this work an experimental and theoretical study of gamma-prompt emission has been carried out with the main aim being to understand to what extent this approach can be used during a treatment based on proton-boron fusion therapy. An experimental campaign, carried out with a high purity Germanium detector, has been performed to evaluate the gamma emission from two pure 11B and 10B targets. Furthermore, a set of analytical simulations, using the Talys nuclear reaction code has been performed and the calculated spectra compared with the experimental results. These comparisons allowed us to successfully validate Talys which was then used to estimate the gamma emission when a realistic Boron concentration was considered. Both simulations and experimental results suggest that the gamma emission is low at certain proton energies, thus in order to improve the imaging capabilities, while still maintaining the Boron therapeutic role, we propose the addition of natural Copper bound by a dipyrromethene, BodiPy, to boron atoms. Analytical simulations with Talys suggest that the characteristic spectrum of the copper prompt gamma-rays has several peaks in the energetic regions where the background is negligible.

A cheap and efficient diagnostic system for beam monitoring has been recently developed at INFN-LNS in Catania. It consists of a high sensitivity CCD camera detecting the light produced by an ion beam hitting the surface of a scintillating screen and a frame grabber for image acquisition. A scintillating screen, developed at INFN-LNS and consisting of a 2 μm BaF2 layer evaporated on an aluminium plate, has been tested by using (20)Ne and (40)Ar beams in the keV energy range. The CAESAR ECR ion source has been used for investigating the influence of the frequency and magnetic field tuning effects, the impact of the microwave injected power, and of the focusing solenoids along the low energy beam transport on the beam shape and current. These tests will allow to better understand the interplay between the plasma and beam dynamics and, moreover, to improve the transport efficiency along the low energy beam line and the matching with the superconducting cyclotron, particularly relevant in view of the expected upgrade of the machine.

We show the results of some test beams performed on a new monolithic strip silicon detector telescope developed in collaboration with the INFN and ST-microelectronics. Using an appropriate design, the induction on the ΔE stages, generated by the charge released in the E stage, was used to obtain the position of the detected particle. The position measurement, together with the low threshold for particle charge identification, allows the new detector to be used for a large variety of applications due to its sensitivity of only a few microns measured in both directions.

For measuring fusion excitation functions, the activation technique with a stack of targets offers the considerable advantage that several reaction energies may be simultaneously measured by using one beam energy. However, its main drawback is the degradation of the beam quality as it passes through the stack due to statistical nature of energy loss processes and any non-uniformity of the stacked targets. If not taken properly into account, this degradation can lead to a wrong determination of the fusion excitation function. In this contribution some results of the investigation of this problem are reported.

Elastic scattering angular distributions for the weakly bound nucleus $^{7}\mathrm{Li}$ on $^{64}\mathrm{Zn}$ have been measured in a wide angular range at energies around the Coulomb barrier. The present experimental data and our previously measured elastic scattering data for the system $^{6}\mathrm{Li}+^{64}\mathrm{Zn}$ have been analyzed within the continuum-discretized coupled-channels method, where the resonant and nonresonant states of the projectile are taken into account. In this theoretical framework, we have also analyzed our previously measured excitation functions of elastic scattering at backward angles and the corresponding barrier distributions for the same systems. A good agreement between the experimental data and the calculations has been observed. The obtained results, besides confirming the importance of the coupling to the breakup channels in collisions with weakly bound nuclei, show that, in the case of $^{6}\mathrm{Li}$, the inclusion of the resonant states of the projectile produces non-negligible effects.

Fusion barrier distributions for the 20 Ne + 112,116,118 Sn systems have been extracted from quasi-elastic scattering cross sections measured at the Warsaw HIL Cyclotron. Results are compared to coupled-channels calculations performed with the CCFULL code. The overall widths of the distributions are reproduced on taking account of the low-lying collective states of the target and projectile but some puzzling discrepancies in their shapes remain to be explained.

The possibilities presented by the improved portable PIXE system are discussed. Examples are given of applications in the cultural heritage field, and in particular in the characterization of pigments and silver patina on ancient Roman coins. The limitations of the system are also discussed.

For low energy reaction studies involving radioactive ion beams, the experimental reaction yields are generally small due to the low intensity of the beams. For this reason, the stacked target technique has been often used to measure excitation functions. This technique offers considerable advantages since the reaction cross-section at several energies can be simultaneously measured. In a further effort to increase yields, thick targets are also employed. The main disadvantage of the method is the degradation of the beam quality as it passes through the stack due to the statistical nature of energy loss processes and any nonuniformity of the stacked targets. This degradation can lead to ambiguities of associating effective beam energies to reaction product yields for the targets within the stack and, as a consequence, to an error in the determination of the excitation function for the reaction under study. A thorough investigation of these ambiguities is reported, and a best practice procedure of analyzing data obtained using the stacked target technique with radioactive ion beams is recommended. Using this procedure a re-evaluation is reported of some previously published sub-barrier fusion data in order to demonstrate the possibility of misinterpretations of derived excitation functions. In addition, this best practice procedure has been used to evaluate, from a new data set, the sub-barrier fusion excitation function for the reaction Li-6+ Sn-120.

We have measured the angular distributions and the forward recoil range distributions of residues produced in the interaction of, respectively, 151, 228 and 402 MeV 12C ions with 103Rh and the forward recoil range distributions of residues produced in the interaction of 303 MeV 16O ions with 103Rh. These data have been successfully reproduced by a theory which assumes that the dominant mechanisms are complete and incomplete fusion of the projectile with the target and single nucleon transfers from the projectile to the target and predicts that, starting from an incident energy of about 250 MeV, a large fraction of the residues has a mass and charge very close to those of the target nucleus. This is because, at incident energies of a few hundred MeV, a large fraction of the kinetic energy of 12C and 16O is carried away by fast ejectiles which then leave behind the intermediate equilibrated nuclei with a rather small excitation energy and small forward linear momentum.

We developed a technique for thermal neutron detection not making use of 3 He, also suitable for online real time monitoring of CASTOR spent fuel containers. As a neutron converter we used 6 LiF, being the neutron capture cross section of 6 Li very well known and with only an alpha and a triton in the exit channel. We can deposit thin layers of converter onto several different substrates, to be placed on top of solid state detectors or scintillators capable of efficiently detecting the decay products.

At the Istituto Nazionale di Fisica Nucleare Laboratorio Nazionale del Sud of Catania, a K=800 superconducting cyclotron is in operation since 1994. The accelerator beam extraction is accomplished using electrostatic deflectors constituted by HV electrodes generating electric fields to 140 kV/cm in 6 to 8 mm gaps. The electrostatic performance is strongly dependent on the presence of high magnetic fields (up to 5 T) and of high ion energy and intensity of heavy ion beams. The behavior of these systems is mainly determined by the field electron emission effects on the cathode surface, by electron focalization processes due to the magnetic field and by heating effects due to the ion beams. A detailed study of these effects is under development starting with point, the characterization of the electrode surface vs. the material used (Ti, Cu, stainless steel, etc.) and of the best mechanical and chemical treatment available, Moreover, we are studying the electrostatic performance by using titanium surfaces and nitriding over a wide temperature range (300 to 800/spl deg/C). Preliminary results concerning the use of thermal processed polished surfaces are presented and discussed.

Fifty-three excitation functions for the production of radioactive residues in the interaction of 12C with 103Rh have been measured from the Coulomb barrier up to 400 MeV by means of the activation technique. These excitation functions have been analyzed considering complete fusion, incomplete fusion of 8Be and α-particle fragments and, above about 200 MeV, the transfer of either one proton or one neutron from 12C to 103Rh. The emission of pre-equilibrium particles during the thermalization of the excited composite nuclei formed in all these processes and, in the case of 8Be and α incomplete fusion, also the re-emission of α-particles after a mean-field interaction or a few interactions with the target nucleons have been taken into account.

Excitation functions for the production of heavy residues have been measured for the collisions ${}^{6,7}\mathrm{Li}+{}^{64}\mathrm{Zn}$ at energies around and below the Coulomb barrier. The cross sections for heavy residue production have been measured using an activation technique, detecting off-line the characteristic atomic x-rays emitted in the electron capture decay of the reaction products. The experimental relative yields of the residues have been compared with statistical model calculations performed by using the code cascade. Such a comparison suggests that heavy residue production is dominated by complete fusion at above-barrier energies, whereas different processes like incomplete fusion and/or transfer become dominant in the sub-barrier energy region. The heavy residue excitation function ratio between the ${}^{6}$Li- and ${}^{7}$Li-induced collisions shows an increasing trend as the energy decreases below the barrier.

We have measured the excitation functions of several reactions occurring in the fusion of $^{12}\mathrm{C}$ with $^{103}\mathrm{Rh}$ at incident energies up to about 230 MeV. The data can be satisfactorily reproduced by considering the preequilibrium emission of particles during the thermalization of the composite nucleus. The energy evolution of the mean-field interaction is also discussed. \textcopyright{} 1996 The American Physical Society.

An alpha source which consists of 1 mCi of 210Po electro-deposited on 1 μm thin Ag foil attached to a ceramic backing has been prepared. The overall geometry exhibits a truncated-conical shape. The source has been coupled to a standard 10 mm diameter Si(Li) X-rays detector connected to a portable electronic system (ORTEC-NOMAD). The analysed area of the exposed samples is 16 mm in diameter. Preliminary results state that medium-light elements, like Ca, Ti, Fe, Co, Cr, Ni and Cu can be easily analysed at concentrations of some per cent. Lighter elements determination is affected by the enhancing presence of X-rays generated in the Ag foil and by some chlorine impurities. PIXE measurements of attic greek pottery sherds are discussed.

A new version of the portable polonium source, named L-PIXE (large-particle induced X -ray emission), to be used for the non-destructive analysis in the Cultural Heritage field, was realised in the framework of a collaboration between the Italian LNS-INFN (Laboratori Nazionali del Sud-Istituto Nazionale di Fisica Nucleare) and IBAM-CNR (Istituto per i Beni Archeologici e Monumentali-Consiglio Nazionale delle Ricerche). The new source presents a compact geometry and it was designed to operate with large area SDD (silicon drift detector) detectors. In particular, the L-PIXE source was coupled to a 50 mm² SDD detector and tested by measuring geochemical reference materials. Results evidenced a gain factor, in terms of counting statistics in the measured X -ray spectra, equal to 11–12 with respect to the previous versions of the source. A preliminary evaluation of the MDL (minimum detection limit) of the new experimental set-up evidenced the possibility of using the new L-PIXE source for identifying the presence of minor and, in some cases, trace elements composing samples under investigation.

Fusion cross sections for the 6Li+120Sn and 7Li+119Sn systems have been measured. We aim to search for possible effects due to the different neutron transfer Q-values, by comparing the fusion cross sections for the two systems below the barrier. This experiment is the first step of a wider systematic aiming to study the above problems in collisions induced by stable and unstable Li isotopes on tin all forming the same compound nucleus.

The excitation functions for production of 21 isotopes and isomers of Au, Pt, Ir, Os and Re in the interaction of12C with181Ta from 54 to 98 MeV incident energy have been measured by the activation technique. The analysis of these data allows one to estimate the reaction cross-section and the cross-sections for complete fusion of12C and the incomplete fusion of8Be and α fragments with tantalum.

A facility of the Italian Laboratorio Nazionale del Sud , used for systematic investigation of heavy ion reactions with activation techniques since October 1991, is described.

New fusion data for the {sup 4}He+{sup 64}Zn system at sub-barrier energies are measured to cover the same energy region of previous measurements for {sup 6}He+{sup 64}Zn. Aim of the experiment was to compare the fusion excitation functions for the two system to investigate on the effects of the {sup 6}He neutron-halo structure on the fusion reaction mechanism at energies around the Coulomb barrier. The fusion cross section was measured by using an activation technique. Comparing the two systems, we observe an enhancement of the fusion cross section in the reaction induced by {sup 6}He, at and below the Coulomb barrier.

The excitation functions for production of nineteen isotopes of At, Po, Bi, Pb, and Tl in the interaction of $^{12}\mathrm{C}$ with $^{197}\mathrm{Au}$ between 57 and 97 MeV incident energy have been measured with the activation technique. The analysis of these data allows one to estimate the cross sections for complete fusion of $^{12}\mathrm{C}$ and incomplete fusion of $^{8}\mathrm{Be}$ and \ensuremath{\alpha} fragments with gold, and shows the presence of preequilibrium emissions at incident energies only slightly higher than the Coulomb barrier acting between $^{12}\mathrm{C}$ and $^{197}\mathrm{Au}$.

In this paper is presented the new LAB-alfa laboratory of the LNS-INFN, a facility devoted to manipulate heavy radionuclide for the production of portable non contaminant 210-Po sources for application in the cultural heritage field.

A new portable system that performs simultaneous particle induced x-ray emission and x-ray fluorescence analysis is described. It is based on the use of a 244Cm radioactive source as α-particle and x-ray emitter, coupled to a Si drift detector. Particular care has been devoted to the choice of the materials surrounding the source. X-ray fluorescence spectra are presented, showing high detection efficiency for elements from Na (K lines) to Pb (L and M lines). The system can be used as a qualitative tool for ‘fingerprint’ analysis and, in some cases, as a quantitative one. Examples are presented and discussed. Copyright © 2007 John Wiley & Sons, Ltd.

An oven for the feed of vapors from solid materials in the Superconducting Electron cyclotron Resonance ion SourcE (SERSE) has been designed, built and tested at the Laboratorio Nazionale del Sud. It is based on an electrically heated tungsten filament. In order to have a correct temperature distribution in the whole system and to lower the heating power, a finite elements code has been used for the design of busses and thermal shielding. A crucible temperature of 2000 °C has been measured by a pyrometer and a W/Re thermocouple. The tungsten filament as well as the other components have shown no significant damage, confirming the robustness and reliability of the system. Satisfactory Ni evaporation rates have been measured.

Intermediate energy heavy ion collisions are unique probes to study the properties of nuclei far away from the nuclear ground state. The CHIMERA detector is a powerful second generation 4/spl pi/ array conceived to study nuclear reactions at intermediate energies. The array has 1192 detection cells covering almost 95% of total solid angle. The CHIMERA device operated at the Laboratori Nazionali del Sud in Catania in four campaigns in 2000, 2003, 2004 and 2005, showing very good performances in the detection and identification capabilities. Experimental results are presented, together with the improvement in progress to extend further the detection and identification capabilities.

International audience; The present paper concerns the study of reactions induced by radioactive beams of halo and weakly bound nuclei at energies around and above the Coulomb barrier. The results obtained for the reaction induced by the halo nucleus 6He on 64Zn have been compared with the results for the reaction induced by 4He on the same target. The results of the reaction induced by the weakly bound unstable 13N on the weakly bound 9Be have been compared with those for the reaction 10B + 12C.

A new portable XRF spectrometer which allows control of the energy and the intensity stability of the emitted x-ray beam has been designed and built. The control is obtained by measuring the x-ray fluorescence generated by a double Ag/Ba thin target when crossed by the x-ray beam during a measurement. The silver and barium fluorescence K lines are detected by an ancillary Si-PIN detector and analysed by software developed at the LNS/INFN laboratories. The new portable spectrometer, the beam stability control method, the evaluation of the system and some quantitative applications of interest in the cultural heritage field are presented and discussed. Copyright © 2004 John Wiley & Sons, Ltd.

“In situ” non-destructive characterization of the blue pigments present in the ceramic glazes of Della Robbia sculptures have been carried out at the Bargello museum in Florence. PIXE and XRF portable systems have been used to determine the matrix composition and the trace-elements, respectively. The results indicate that the arsenic is present as trace-element only after 1520.

In the 1996 the feasibility of a portable PIXE has been demonstrated and a system has been realized thanks to a collaboration between the Laboratori Nazionali del Sud of Catania and the CEA-DIMRI of Saclay. The 210Po alpha-emitter of 37 MBq was used as a source for X-ray fluorescence excitation of the chemical elements present in the sample. More recently important improvements have been introduced: the actual system is able to detect elements as light as Na, to reach good energy resolution (140 eV at 5.9 keV) and to obtain good statistics in a reasonable measurement time (typically 15 min) for major elements when a freshly produced source is used. Due to the stability of the experimental parameters (incident energy, beam intensity, geometry), measurements are very reproducible and absolute values of the concentration are easily obtained by using reference standard calibration samples. The GUPIX code is used in the alpha-particle option. Accuracy and precision are obtained by using repeated measurements on different reference standards. Recent applications concern: the analysis of the bleu glazes of the Della Robbia terracotta at the National Museum of Bargello in Florence, the pigments characterization of a Pontificale of the XII century, the characterization of the silver patina in ancient coins. Some applications in the determinations of the S and Cl content in building stone materials and preliminary data in atmospheric pollutants are also presented.

The results concerning the study of 6 Li+ 120 Sn and 7 Li+ 119 Sn systems are presented. These two sistems are characterised by very similar structures of the interacting nuclei and by different Q-value for oneand two- neutron transfer. Our aim is to disentangle the possible effects due to the different n-transfer Q-values, at sub-barriers energies, by comparing the two fusion excitation function. In these experiments the fusion cross section has been measured by using a stack activation technique. No particular differences in the two fusion excitation functions have been observed. The influence of transfer channels on fusion cross-section has been object of investigations in the last years. In particular, the possible dependence of the fusion cross-section on the sign of the neutron transfer Q-value has been much debated in literature. The systematic approach used for the study of the Ca+Zr systems [1] provided relatively clear evidence of the relation between sub-barrier-cross section and the sign of the neutron transfer Q-value, in a model-independent way. According to experimental

In this paper, a new version of the LNS portable PIXE-alpha system is presented. This version allows to perform measurements on small dimension (few millimetres) artefacts. As the previous one, the present system is particularly suited for the elemental characterization of thin layers (2-3 ?m) and is made up by a 1 mCi 210-Po alpha source, coupled to a germanium detector having an energy resolution of 130 eV at 5.9 KeV and a 8 ?m Be window. With this system it is possible to evidence the K-lines of low and medium atomic number elements (from Mg to Zn) and to well separate the L and M-lines of high atomic number elements.

Da qualche anno i pigmenti di rivestimento delle ceramiche Robbiane sono stati oggetto di caratterizzazione e di studio da parte dei gruppi di Firenze e di Genova adoperando la tecnica PIXE con acceleratori. In particolare si è cercato di determinare la presenza di arsenico in quanto tale elemento risulta utile alla datazione delle opere essendo presente solo a partire da una certa data in poi. Molte indagini sono state così effettuate, anche nel quadro della collaborazione europea COST G8, su frammenti trasportabili presso i laboratori di analisi. Recentemente presso i LNS a Catania sono state sviluppate tecniche di analisi elementare (PIXE ed XRF) con strumenti portatili. Si è potuto cosi intervenire direttamente sulle opere Robbiane conservate presso il Museo del Bargello e caratterizzare sul posto i pigmenti dei rivestimenti. In una prima campagna di misure effettuate accoppiando le tecniche PIXE ed XRF si è determinata tramite il PIXE la matrice (Na, Mg, Al, Si, K, Ca, Pb) e tramite XRF gli elementi in traccia caratterizzanti (Fe, As, Ni, Co, Cu). I dati ottenuti sono di tipo quantitativo (ovviamente nell'ipotesi che i rivestimenti analizzati siano di composizione omogenea). Si presentano gli strumenti e i risultati ottenuti.

In this paper, a new version of the LNS portable PIXE-alpha system is presented. This version allows to perform measurements on small dimension (few millimetres) artefacts. As the previous one, the present system is particularly suited for the elemental characterization of thin layers (2-3 ?m) and is made up by a 1 mCi 210-Po alpha source, coupled to a germanium detector having an energy resolution of 130 eV at 5.9 KeV and a 8 ?m Be window. With this system it is possible to evidence the K-lines of low and medium atomic number elements (from Mg to Zn) and to well separate the L and M-lines of high atomic number elements.

Because of its high radiation hardness, diamond can be used better than other materials in the intense radiation field characterizing the interior region of a particle beam in an accelerator. In effect, the measurements reported here were carried out by placing diamond detectors under continuous irradiation in the 26-MeV proton beam of the 15-MV TANDEM accelerator of Southern National Laboratory (LNS) of INFN in Catania. The diamond detectors were built in the Rome Tor Vergata Laboratory. Diamond films were deposited by microwave plasma enhanced chemical vapor deposition on silicon substrates. A four-pixel beam monitor prototype was then realized by depositing four titanium gold contacts on the diamond surface. The signal was found to be stable and reproducible. The collected charge in DC mode was more than 20 000 electrons/protons for a diamond thickness of 65 μm, thus exhibiting a gain of approximately 10 4 with respect to the Faraday cup. For the measured samples, both response and release times of approximately 1 s were observed in the above experimental conditions. An analysis of the relative sensitivity between pixels was also performed. No differences of the detector current and Faraday cup current ratio were observed for different pixels, indicating the homogeneity of the beam monitor response.

A new version of the LNS portable PIXE-alpha system is presented. This version allows to perform measurements on small dimension (few millimeters) details of artefacts. By the use of a He flux it is possible to reduce the air absorption of low energy X-rays and to evidence the presence of light mass number elements as well as of silver patina thanks to the Ag L-lines detection.

Fusion excitation functions have been measured for the 6 Li+120 Sn and 7 Li+119 Sn systems at energies around the Coulomb barrier, to investigate the effects of neutron transfer and breakup on the fusion process. At energies above the barrier, a suppression of the complete fusion excitation function with respect to the prediction of the 1D - Barrier Penetration Model has been observed, in both cases. At energies below the Coulomb barrier, no significant difference between the two excitation function, imputable to the different neutron transfer Q-values of the two systems has been observed.

A semiconductor detector coupled with a neutron converter is a good candidate for neutron detection, especially for its compactness and reliability if compared with other devices, such as 3He tubes, even though its intrinsic efficiency is rather lower. In this paper we show a neutron detector design consisting of a 3 cm × 3 cm silicon pad detector coupled with one or two external 6LiF layers, enriched in 6Li at 95%, placed in contact with the Si active surfaces. This prototype, first characterized and tested at INFN Laboratori Nazionali del Sud and then at JRC Ispra, was successfully shown to detect thermal neutrons with the expected efficiency and an outstanding gamma rejection capability.

Background Crohn’s disease (CD) is a chronic intestinal disorder characterized by overproduction of inflammatory cytokines and recurrent abdominal pain. Recently, brain morphological abnormalities in the pain matrix were found in patients with chronic pain disorders including irritable bowel syndrome. To investigate potential structural brain changes associated with CD, we used magnetic resonance imaging (MRI). Furthermore, we tested whether in patients gray matter (GM) volumes correlated with disease duration. Methods Eighteen CD patients in remission and 18 healthy controls underwent structural MRI. Voxel-based morphometry (VBM) is a fully automated technique allowing identification of regional differences in the amount of GM enabling an objective analysis of the whole brain between groups of subjects. VBM was used for comparisons and correlation analysis. Key Results With respect to controls, CD patients exhibited decreased GM volumes in portion of the frontal cortex and in the anterior midcingulate cortex. Disease duration was negatively correlated with GM volumes of several brain regions including neocortical and limbic areas. Conclusions & Inferences Crohn’s disease is associated with brain morphological changes in cortical and subcortical structures involved in nociception, emotional, and cognitive processes. Our findings provide new insight into the brain involvement in chronic inflammatory bowel disorders.

During a period of 23 years, 57 patients who had an initial neck node biopsy elsewhere, with the diagnosis of metastatic squamous cell carcinoma established, underwent curative resection by our department after the site of head and neck primary was found. Ten patients free of disease died of other causes, leaving 47 patients who were eligible for at least 3 years of follow-up. Nineteen patients are aliye after 3 or more years. The incidence of recurrence in the neck was 57% (27/47). The 3-year survival in this group of Stage III was 40% (19/47) and 5-year survival was 34% (16/47). Compared with historical data, it appears from the present study that a previous biopsy of a neck node did not adversely affect the incidence either of neck recurrence or survival when appropriate surgery is performed.