Study of charged particles interaction processes on Ar in the 0.2 - 2.0 GeV energy range through combined information from ionization free charge and scintillation light

The Thesis paper will report an overview on the commissioning and MC studies for the LArIAT experiment. LArIAT stands for Liquid Argon Time Projection Chamber In A Testbeam. The LArIAT experiment is part of the LArTPC Neutrino program at Fermilab. Main purpose of the experiment is to perform a precise ``calibration” of the Liquid Argon TPC detector. The main goal is the optimization of the offline algorithms for Particle IDentification and calorimetric reconstruction for Liquid Argon detector technology, both TPC wires signals and LAr scintillation light collection. LArIAT experiment aims to study of all the particle types emerging from (neutrino,Ar) interaction, for neutrino energies of few GeV, typical of the SBN and LBN programs, by means of charged particles of defined species (mainly pions, protons, muons, electrons, kaons...), momentum (0.2 - 2.0 GeV/c range) and sign provided by a dedicated TestBeam line. One of the goals of the LArIAT experiment will be the experimental measurement of charged pion cross section on Ar in the 0.2 to 2.0 GeV energy range. The goal of a dedicated pion run with LArIAT is to develop pion identification algorithms based on their interaction modes in Argon and to exploit direct and precise measurement of the pion-nucleus cross-sections to reduce the uncertainty on the hadron interaction models adapted in MC simulations for Ar target. A study of charged pion interactions in Liquid Argon target and the development of a routine to evaluate the total interaction cross section, that could be later applied to real data from the TPC, has been the first and software oriented topic of my Thesis. Another goal for the LArIAT experiment will be the development, test and characterization of dedicated devices for LAr scintillation light collection. LAr scintillation light is now used only for triggering purposes; the aim is to extend its use for calorimetric energy reconstruction to improve the energy resolution of this detector technology. Actually two different light collection syst! ems have been implemented in LArIAT cryostat, two PMTs and three SiPM readout boards. The development and test of LAr light collection optical devices, especially dedicated cold front-end electronics for SiPM devices, for LArIAT has been the second and hardware oriented topic of my Thesis.