Tag Archives: Evento scientifico

A new design of thermal neutron irradiation facility, called HOTNES (HOmogeneous Thermal NEutron Source), was prototyped within the INFN-LNF / ENEA-Frascati collaboration. HOTNES is a polyethylene assembly, with about 70 cm × 70 cm square section and 100 cm height, including a large, cylindrical cavity with diameter 30 cm and height 70 cm. The facility is supplied by a 241Am-B source located on the cavity bottom. A specially studied combination of reflecting and attenuating parts produces constant values of fluence rate over irradiation planes as large as 30 cm in diameter. By varying the irradiation plane, the thermal fluence rate can be varied from about 700 cm-2 s-1 to 1000 cm-2 s-1. The facility design, previously optimized by Monte Carlo simulation, was experimentally verified. The main features of the HOTNES facility and the neutron field characterization will be presented.

The HOmogeneous Thermal NEutron Source (HOTNES) is a new type of thermal neutron irradiation assembly developed by the ENEA-INFN collaboration. The facility was fully characterized in terms of neutron field and dosimetric quantities, by either computational and experimental methods. The results of the first “HOTNES users program”, carried out in 2016, and covering a variety of thermal neutron detectors such as scintillators, solid-state, single crystal diamond and gaseous detectors will be presented and the future perspectives outlined.

A selection of the most recent results from the CMS experiment will be presented. The results are based on the analysis of the proton-proton (pp) collision data delivered by the LHC in year 2016, at an energy of 13 TeV in the pp centre of mass system, corresponding to an integrated luminosity of about 40/fb. The LHC and CMS performance will be briefly described. The latest updated results on the standard model (SM) precision measurements for the scalar and top sectors will be first presented. It includes the new H scalar property measurements from the 4 lepton decay channel and the 3 sigma evidence for the ttH coupling, in the multi lepton final states. In the second part, the latest results on the searches for new physics beyond the SM will be presented, including searches for dark matter particles.

The $eta$ meson is almost unique in the particle universe since it is a Goldstone boson and the dynamics of its decay are strongly constrained. Because the eta has no charge, decays that violate conservation laws can occur without interfering with a corresponding current. The integrated eta meson samples collected in earlier experiments have been less than ~$10^8$ events, limiting considerably the search for such rare decays. Only recently, WASA-at-Cosy produced about 10^9 eta, starting to breach into new physics. A new experiment, REDTOP, is being proposed to the scientific community with the intent of collecting more than $10^{13}$ triggers/year for studies of rare $eta$ decays. Such statistics are sufficient for investigating several symmetry violations, and for searches for new particles beyond the Standard Model. The physics program, the accelerator systems and the detector for REDTOP will be discussed during the colloquium.

Open Day Imprese 15 giugno 2017 INFN-LNF Auditorium Bruno Touschek Il trasferimento tecnologico dalla ricerca alla rete imprenditoriale I Laboratori Nazionali di Frascati dell’INFN, in collaborazione con le Sezioni INFN romane e con il Patrocinio della Regione Lazio, organizzano per il 15 giugno un Open day per le imprese, per avviare potenziali collaborazioni finalizzate all’accesso ai prossimi bandi pubblici di finanziamento che prevedano un partenariato tra Enti di Ricerca e Aziende. Il programma prevede una sessione di interventi legati ad iniziative di trasferimento tecnologico in atto, ed una tavola rotonda per la discussione; per chi è interessato nel primo pomeriggio ci sarà una visita alle infrastrutture di ricerca tecnologica dei Laboratori Nazionali di Frascati. Comitato Organizzatore R. Ammendola – INFN Roma Tor Vergata A. Budano – INFN Roma Tre C. Cantone – INFN LNF M.Cestelli Guidi – INFN LNF (Chair) A. Lonardo – INFN Roma Sapienza Segreteria Organizzativa D. Ferrucci – INFN LNF Web Support G. Basso – INFN LNF

Ion beams, after over 50 years of exploitation and optimization, have grown to be a key tool in modern tumour treatment. Currently over 50 ion therapy centres are in operation worldwide, next few tens are under construction. However, despite decades of experience, lack of in-vivo and in-situ monitoring methods disables full exploitation of excellent physical and biological properties of hadron beams. In my talk I will briefly remind the idea and the history of ion beam therapy. I will review methods of online range monitoring being developed by different group in the world, and focus on the Krak?w-Aachen-Katowice project.

This workshop is organized in the framework of the Foundational Questions Institute, FQXI, project: “Events” as we see them: experimental test of the collapse models as a solution of the measurement problem, and is sponsored by INFN. The aim of the workshop is to discuss the possible limits of validity of quantum mechanics, the collapse models and, more generally,  theories which go beyond the standard quantum mechanics, as well as experiments aiming to test them. Also, in this context, the role that gravity may play will be discussed. From the theoretical point of view, since the Einstein-Bohr debate, quantum mechanics never stopped raising questions about its meaning. In particular, the transition from the microscopic world, where systems are observed in a superposition of different quantum states, to the macroscopic world, where systems have well defined positions (the so-called “measurement problem”), never stopped to puzzle the scientific community. For this reason, scientists are pushed to look for theories beyond the standard quantum formulation. From the experimental point of view, quantum mechanics is the best verified available theory. It is therefore a very compelling challenge to look for possible small violations predicted by alternative quantum theories. The aim is either to put stronger observational bounds on the new theories, i.e. on model's parameters, or, much more exciting, to find a violation of standard quantum mechanics when compared with the new theories' predictions. In this framework, a deeper understanding of the possible limits of validity of the quantum superposition principle is an interesting …

Heavy-ion collisions offer a unique possibility to explore in the laboratory the hot and dense deconfined phase of strongly-interacting matter: the Quark Gluon Plasma (QGP). In this context, measurements performed in smaller systems, such as proton–proton and proton–nucleus collisions, provide the reference data for the interpretation of the heavy-ion collision results. However, measurements obtained in high-multiplicity pp{} and pPb{} collisions at the LHC have exhibited features that are similar to what was observed in PbPb{} collisions, where they are usually interpreted as signs of collective behaviour. These observations warrant a comprehensive study of the production of identified particles which are important probes to investigate the dynamics of the small systems. Thanks to the excellent particle identification performance of the ALICE detector the measurement of identified particles is possible over a wide range of transverse momentum ($pt{}$). In order to discuss the similarities between the different collision systems, the results obtained in pp{}, pPb{} and PbPb{} collisions will be reviewed.

Photocathode technology in accelerator science is an exciting and growing field of research and development. Prior to the first implementation of a photocathode in the RF gun operated at Los Alamos National Laboratory in 1985, thermionic cathodes were typically used in electron guns. Switching from the thermionic cathode to a laser driven photocathode offered a monumental improvement in the overall beam quality. With the advent of the photoinjector, the emittance reduced by over a factor of 10, compared with a thermionic injector. Photocathode research is increasingly important to meet the demands of modern accelerators. In linear accelerator driven 4th generation Free Electron Lasers, the final beam quality is set by the linac and ultimately by its photoinjector and photocathode. Therefore, to deliver cutting-edge beam characteristics, linac based sources have stringent requirements particularly with respect to the photocathode used in the photoinjector. Understanding how surface properties of materials influence photocathode properties such as Quantum Efficiency (QE) and intrinsic emittance is critical for such sources. Metal cathode R&D at Daresbury Laboratory (DL) is driven by our on-site accelerators VELA (Versatile Electron Linear Accelerator) and CLARA (Compact Linear Accelerator for Research and Applications); the Free Electron Laser test facility at DL. Metals offer the advantage of a fast response time which enables the generation of short electron pulses. Additionally, they are robust to conditions within the gun cavity. In this work, the effect of different preparation procedures on the surface composition, work function and QE was investigated for a range of metal photocathode …