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What Napoleon and Fukushima have in common? Nothing but…a physicist!

Febbraio 3, 2016 Non categorizzato 201 Views

Recent searches in particle and astroparticle physics are based on experiments looking for the so called “rare events” like interactions of neutrinos or of other mysterious particles like those which constitute the invisible “Dark Matter” which permeates our Universe. These events can be simulated by a background of spurious processes produced by cosmic rays and/or by natural radioactivity . While cosmic radiation is strongly suppressed by operating the experiment underground, the real challenge consists in detection and possible eliminations of trace elements which could fake those which we are looking for. A powerful technique to search for these elements is the “neutron activation”. where the sample is bombarded by a flux of neutron which transforms the searched atoms in radioactive ones allowing to detect the consequent radioactivity. A typical example is the past measurement by our group of the presence of Arsenic in the hairs of Napoleon which led to the evidence that the Emperor was not assassinated.This and other techniques have been successfully employed in archaeometry with the typical search on the presence of the isotope ²¹⁰Pb which is present in natural Lead but not in the ancient one since its decay reduces its presence by one half in 22.3 years.Of considerable impact on the public were our measurements of the radioactivity in Milano air due to the Chernobyl and Fukushima nuclear accidents. In the latter case, despite the very large distance from the reactors, our detector could reveal a very low radioactivity even if it was million times less than in Fukushima showing that it was extremely below any possible physical damage in our country.

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ABOUT THE SPEAKER

ETTORE FIORINI

His searches have been mainly addressed to experimental nuclear and subnuclear physics. Among the first results particular relevance had the study on the neutrino properties and the participation of the discovery of weak neutral currents. Later he suggested and carried out the first experiment on double beta decay of ⁷⁶Ge and directed the NUSEX experiment which has yielded the first significant results on the nucleon decay and on the penetrating component of cosmic rays. More recently he has participated with Till Kirsten to the underground Gallex experiment, carried out in the Laboratory Nazionali del Gran Sasso, which was the first to prove of the presence of neutrinos generated by the proton-proton reactions inside the Sun. His present activity is mainly devoted to the use of thermal detectors in the search of rare events., a technique first suggested by him with Tapio Niinikski in 1983. He founded the International experiment CUORE ( for Cryogenic Underground Observatory for Rare Events) whose main aim is the search for neutrinoless double beta decay of 130Te, presently in construction, and of its reduced scale CUORICINO and CUORE0 still among of the most sensitive ones in the international arena. He is also involved in problems of health physics with particular reference to Environmental Radioactivity and in multisciplinary searches in Archaeometry. “Professore emerito” at the Universita’ di Milano-Bicocca and national member of the ‘ Accademia Nazionale dei Lincei and of other Academies, is recipient of the Enrico Fermi Prize of Societa’ Italiana di Fisica, of the medal of “ Benemeriti della Scienza e della Cultura” of the President of the Italian Republic and of the Bruno Pontecorvo Prize by the International Institute of Nuclear Physics (Russia).