Dr. Giussepe Viesti (giuseppe.viesti@pd.infn.it). Istituto Nazionale di Fisica Nucleare, e Dipartimento di Fisica della Università di Padova, Italia.
El Prof. Viesti es un invitado de la USB financiado por el DID, Ciencias Básicas. Es parte de una colaboración entre la USB y la Universidad de Padua, Italia.
Seminario Titulado: Material recognition using neutron/gamma interrogation with time tagged fission sources. Mayo 2009.
Abstract: Material recognition by measuring simultaneously transmission of neutron and gamma ray from a spontaneous fission source has been studied and the average atomic number resolving power determined.
In addition, the possibility of deriving direct signatures able to identify light elements (C,N,O) using the measured transmission versus neutron time of flight is demonstrated. This allows one to determine the relevant elemental ratios (C/O and C/N) that are normally used to identify threat organic materials as explosives and drugs.
On the heavy element side, it is proposed that the discrimination between different materials might also by optimized by implementing the measurement of the average absorption coefficient for gamma rays as a function of the energy. This can be measured exploiting the wide energy range of the fission gamma rays. A tomography system based on this technique is under development.
Possible applications e are discussed.