Characterization of a new digital acquisition system for microdosimetry usign at tissue equivalent proportional counter (TEPC): Master thesis of CHIAVACCI, GERARDO

Microdosimetry studies the probability distribution of the imparted energy when an ionizing particle crosses site size in order of the μm. The Tissue Equivalent Proportional Counter (TEPC) is a microdosimetric instrument that measures radiation dose and dose equivalent in complex radiation fields (fields containing a mixture of particle types). The signal processing chain convert the signal from the TEPC in a pulse signal and measure the pulse height distributions which correspond to an energy deposition distribution in the simulated microscopic volume of the detector. The aims of this work are: • To perform a systematic investigation with a new digital acquisition system: by testing the resolution, input counting rate, dynamic range, stability and reproducibility. • To optimize the electronic chain. • To perform microdosimetric measurements with a TEPC with gamma and neutron sources. Lineal energy distributions for neutrons and gamma rays were measured using a TEPC with three different preamplifiers and with both acquisition systems, Inspector from Canberra and the DT5780 from CAEN. A series of measurements were performed with the counter filled with propane-based tissue equivalent gas at operating gas pressure corresponding to a site size of 2.0 μm in diameter.