My research work concerns the study of cosmic ray flux and solar activity variations in the past. For this study we use information registered in meteorites; more precisely we measure the activity of suitable cosmogenic radioisotopes produced in meteorites by nuclear interaction with cosmic rays. As cosmic ray flux is modulated by solar activity, it is possible to reconstruct the solar activity variations at different time scales by studying cosmogenic radioisotopes of different half lives. The main advantage of meteorites lies in the fact that information on solar activity isn't influenced by terrestrial phenomena, unlike other kind of archives such as sea sediments or ice cores.
Since many years, at the Underground Research Station of Monte dei Cappuccini, our group has been studying meteorites, obtained from various museums, by using highly selective gamma-ray spectrometers. Recently we set up a new spectrometer with higher efficiency and resolution, consisting of a HPGe detector (~3 kg), working in coincidence with an active shielding of NaI(Tl) scintillator (~90 kg). With the aim of improving detector stability and accuracy, I worked on the optimization of the electronic chain , as well as the study and characterization of the Ge-NaI coincidence system. The recent measurements of Albareto (fallen near Modena in 1766), Dergaon (India, 2001) and Allegan (Michigan, USA, 1899) have confirmed the system's effectiveness.
As the activity of certain radioisotopes, notably the 44Ti for studying centennial scale solar modulation, is very low, it is necessary to do measurements extending over a long period of time (up to several months). It is therefore fundamental that the spectrometer remains stable during the entire measurement. For this purpose I'm working on the set up of a new data acquisition electronics chain which will guarantee better apparatus stability. Accordingly we mean to develop a new data analysis system. With this new detecting system we aim to measure more meteorites in order to reveal the solar activity modulations in the past with better accuracy.
In parallel our group is studying Earth irradiation in the past and paleoclimatology by means of the measurement of various indices in sea sediments. We investigate the correlation between sediment information and the solar activity variations obtained by the previously described study on meteorites.
Galactic cosmic ray flux decline and periodicities in the interplanetary space during the last three centuries revealed by 44Ti in meteorites; C. Taricco, N. Bhandari, D. Cane, P. Colombetti, N. Verma; J. Geophys. Res., 111, No. A8, A08102
Experimental set-up and optimization of a new gamma-ray spectrometer for the measurement of cosmogenic radionuclides in meteorites; C.Taricco, N.Bhandari, P. Colombetti, N. Verma, G. Vivaldo; Nuclear Instruments and Methods in Physics Research A (in press)
Ottimizzazione di uno spettrometro HPGe+NaI per la misura di radioisotopi cosmogenici in meteoriti; C. Taricco, N . Bhandari, P. Colombetti*, N. Verma, G. Vivaldo; XCII Congresso Nazionale SIF, Torino, Italy, settembre 2006.
Variazioni del flusso dei raggi cosmici galattici negli ultimi 250 anni da misure di radioisotopi cosmogenici in meteoriti; C. Taricco, N . Bhandari, P. Colombetti, N. Verma* and G. Vivaldo; XCII Congresso Nazionale SIF, Torino, Italy, settembre 2006.
Cosmic ray flux variation during mid-19th century revealed by low 44Ti activity in Allegan meteorite; C. Taricco, N. Bhandari, P. Colombetti, N. Verma* and G. Vivaldo; 69th Annual Meeting of the Meteoritical Society, ETH Zurich, Switzerland, August 2006.
44Ti in meteorites and Galactic Cosmic Ray flux over the past 235 years; C. Taricco, N. Bhandari*, D. Cane, P. Colombetti, N. Verma, G. Vivaldo; COSPAR 06 (Committee on Space Research), Beijing, China, July 2006.
Experimental set-up and optimization of a new gamma-ray spectrometer for the measurement of cosmogenic radionuclides in meteorites; C.Taricco, N.Bhandari, P. Colombetti*, N. Verma, G. Vivaldo; X Pisa Meeting – Frontier Detectors for Frontier Physics; La Biodola, Isola d’Elba, Italy, May 2006
Variabilità climatica millenaria rivelata negli ultimi 20000 anni in sedimenti del Mar Tirreno; C. Taricco, S. Alessio, C. Battigelli*, P. Colombetti, N. Verma; XCI Congresso Nazionale della Società Italiana di Fisica, 26 settembre - 1 ottobre 2005, Catania, Italy, (2005) 14
Heliospheric modulation of cosmic rays based on 44Ti in stony meteorites over the past 250 years; C.Taricco, N.Bhandari, P. Colombetti, N. Verma*; Proceedings of the 29th ICRC (International Cosmic Ray Conference), August 2005, Pune, India, 2 p. 195-198
Attività del 44Ti nelle meteoriti: testimone della diminuzione del flusso di raggi cosmici galattici nello spazio interplanetario a partire dal 1700; G. Cini Castagnoli*, C.Taricco, C. Tubiana, P. Colombetti, N.Bhandari, N. Verma; XC Congresso Nazionale della Società Italiana di Fisica, ottobre 2004
* Presenter