[en] Experiments have been carried at INFN-LNS to measure the production rates of ⁷Be, ¹⁸F, ^22,24Na produced in the reaction: ¹⁹F (48 MeV/amu) + ¹²C. In this paper the experimental technique, data analysis and error calculation are reported. The estimated intensities of the secondary beams deliverable to the users vary from 10⁷ to 10⁸ pps/pμA for acceleration at 300 keV and from 10⁵ to 10⁶ pps/pμA for post-acceleration as negative ions into the INFN-LNS tandem

[en] We report our results on the development of astatine negative ion beams free of contaminants

[en] The EXCYT facility (EXotics with CYclotron and Tandem) at the INFN-LNS is under completion and its commissioning with ⁸Li as the first radioactive beam is foreseen by the beginning of 2005. In the following, we report the work done with an emphasis on the expected experimental lithium rates deduced from the tests at GANIL-SIRa and at ORNL-HRIBF. (author)

[en] A new version of integrated target-ion source unit (ionising target) has been developed for the on-line production of radioactive single-charged ions. The target is able to withstand temperatures up to 2500 C and acts also as an ion source of the surface and laser ionisation. Off-line and on-line experiments with the ionising target, housing tantalum foils as a target material, have been carried out at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron) facility. The off-line surface ionisation efficiency measured for stable atoms of Li, Rb and Cs was correspondingly 6%, 40% and 55% at the target temperature of 2000 C and 3-10% for atoms of rare-earth elements Sm, Eu, Tm and Yb at a temperature of 2200 C. The off-line measured values of the ionisation efficiency for stable Gd and Eu atoms by the laser beam ionisation inside the target were 1% and 7%, respectively. The radioactive beam intensities of neutron-deficient rare-earth nuclides from Eu to Lu produced by the integrated target-ion source unit have been measured at a temperature of 2500 C. The results of the integrated target-ion source unit use for on-line laser resonance ionisation spectroscopy study of neutron-deficient Gd isotopes have been also presented. (orig.)

[en] With regard to the ISOL technique, the dependence of intermediate mass (80-160A) production on target and proton beam features has been investigated by means of hadronic transport Monte Carlo codes. The analysis of the target material (mechanism of production), dimensions (length and width) and composition as well as the proton beam energy has shown that in principle, regardless of technological difficulties, the production of neutron-rich isotopes of intermediate mass (80-160 A) can be successfully achieved with proton beams of low-medium energy into uranium thick targets. The power density in uranium targets bombarded by low-medium energy protons has been analyzed too

[en] Ion beams of halogens can be produced either positively or negatively charged, depending on the employed ion source. At CERN-ISOLDE, although positively charged fluorine and astatine can be obtained from a hot plasma ion source, they are often contaminated by isobars and molecular sidebands. This has generated a request from the scientific community for fluorine and astatine negative ion beams free of contaminants. The high selectivity ensured by the surface ionisation process also makes negative beams of chlorine, bromine and iodine highly attractive. However, the efficiency figures for negative surface ionisation of fluorine and astatine were lower than the ones from the hot plasma. Here we report our R and D on new surface ion sources suitable for the production of negative halogen beams.

[en] The EXCYT facility at the INFN-LNS aims to the production of radioactive ion beams to be post-accelerated by a 15 MV Tandem. The primary stable heavy-ion beam (up to 80 MeV/amu, 1 pμA) is supplied by a K-800 Superconducting Cyclotron, which has been operating in a stand-alone mode, by means of the new axial injection beam line, since December, 1999. The magnets of the primary beam line have been aligned and most of the components of the mass separator have been purchased. Different types of Heavy Ion Target-Source (HITS) systems have been built and are here described; in particular, a microwave ion source fully designed and manufactured at LNS has been assembled and successfully tested. Finally, low-intensity beam diagnostics is also ready and reliability tests are under way

[en] The EXCYT facility (EXotics with CYclotron and Tandem) at the INFN-LNS is based on a K-800 Superconducting Cyclotron injecting stable heavy-ion beams (up to 80 MeV/amu, 1 eμA) into a target-ion source assembly to produce the required nuclear species, and on a 15 MV Tandem for post-accelerating the radioactive beams. Since December 1999 the Superconducting Cyclotron operates in a stand-alone mode by means of the new axial injection beam line. The primary beam line has been already mounted and tested. The part of mass separator on the two high-voltage platforms together with low intensity diagnostics is already installed while the ancillary items along with the part of mass separator at ground potential will be installed during the next stop of accelerator operations. The target-ion source unit has been successfully tested on-line at GANIL. The goal of such efforts will be represented by the test of the mass separator with stable beams planned at LNS by the end of the year. The commissioning of the EXCYT facility is foreseen in 2004 together with the start of nuclear experiments program

[en] The mechanobiology is providing novel perspectives in the study of cancer and is contributing to evaluate the cancer responses, from a biophysical point of view, to classical therapeutic approaches- radiotherapy and chemotherapy. Here we have explored the effects of two doses (4 and 8 Gy) of 6 MeV photons on spreading, focal adhesions, migration and mechanical properties of BALB/c 3T3 and their SV40 transformed equivalent, SVT2. Cell biophysical responses to 4 and 8 Gy were analysed and compared with those reported in previous published work when lower doses (1 and 2 Gy) were administered Panzetta et al. (Effects of high energy X-rays on cell morphology and functions. Proc. Book 2017;16:116). We observed that the range of sensitivity to ionising radiations profoundly changes depending on the patho-physiological state of cells. In particular, we found that X-rays induce morphological and functional variations in both cell lines (decreased motility, increased adhesion and increased cytoskeleton stiffness). These changes were slightly dependent on doses in the case of SVT2 cells and may indicate a possible mechanical normalisation in their phenotype. Nevertheless, the responses of BALB/c 3T3 were negligible only for the low dose of 1 Gy and increased significantly in a dose-dependent manner with higher doses. We believe that the characterisation of X-rays effects on the cell mechanobiology could shed new light in the design and customisation of radiotherapy treatments. (authors)

[en] The ternary oxide ceramic system UO₂-ZrO₂-FeO is a refractory system that is of great relevance to the nuclear industry as it represents one of the main systems resulting from the interaction of the Zircaloy cladding, the UO₂ fuel and the structural elements of a nuclear reactor. It is particularly the high temperature properties that require investigation; that is, when substantial overheating of the nuclear core occurs and interactions can lead to its degradation, melting and result in a severe nuclear accident. There has been much work on the UO₂-ZrO₂ system and also on the ternary system with FeO but there is still a need to examine 2 further aspects; firstly the effect of sub-oxidized systems, the UO₂-Zr and FeO-Zr systems, and secondly the effect of Fe/Zr or Fe/U ratios on the melting point of the U-Zr-Fe oxide system. Samples of UO₂-Zr and UO₂-ZrO₂-FeO were fabricated at ITU and then characterized by optical microscopy (OM) and X-ray diffraction to determine the ceramic's structure and verify the composition. Thereafter the samples are to be melted by laser flash heating and their liquidus and solidus temperatures determined by pyrometry. This programme is currently ongoing. The frozen samples, after testing, were then sectioned, polished and the molten zone micro-analytically examined by OM and SEM-EDS in order to determine its structure and composition and to compare with the existing phase diagrams. Examples of results from these systems will be given. Finally, a reacted Zr-FeO thermite mixture was examined, which had been used to generate high temperatures during tests of reactor melt-concrete interactions. The aim was to assess the reaction and estimate the heat generation from this novel technique. These results allow verification or improvement of the phase diagram and are of primary importance as input to models used to predict materials interactions in a severe nuclear accident.