Between October 2007 and June 2012 I was a PhD student at the Particle and Astroparticle Physics Department of the Royal Institute of Technology (KTH), Stockholm, Sweden.
During my PhD I have been part of the PAMELA Collaboration. For 10 years (2006–2016) the PAMELA satellite experiment (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) provided very interesting measurements of the antiparticle cosmic-ray component. 

My PhD work concerned the extension of the positron fraction and of the positron flux measurement beyond 100 GeV and up to 300 GeV, the maximum energy permitted by the PAMELA design. In order to extend positron measurements to higher energies, I developed an alternative technique for positron identification from the overwhelming proton background. In this context, I characterized the hadronic and leptonic shower profile development inside the electromagnetic calorimeter by producing Geant3 simulations, and looking for the best selection criteria. I then applied these selection criteria to real data. As additional cross-check, a multivariate approach has been applied as well. 

The results of my PhD thesis are a substantial contribution to the evaluation of the systematic errors of the final positron flux spectrum published in O. Adriani et al. Cosmic-Ray Positron Energy Spectrum Measured by PAMELA. Physical Review Letters, 111: 081102, 2013.