Comparison of three pulse processing systems for microdosimetry

Three different pulse processing systems coupled to a tissue-equivalent proportional counter were tested in performance for various counting rates. The Tandetron accelerator at the McMaster Accelerator Laboratory was used to produce a mixed neutron-gamma field. Depending on the proton energy, different neutron and gamma dose rates were observed. The proton energy ranged from 1.8 to 2.5 MeV with the current set at 100, 200 and 300 muA. The three pulse height analysis systems used were a Conventional Analogues System (CAS), a Real Time System (RTS) and a Digital Pulse Processing System (DPP). The results have shown consistent microdosimetric spectra. The neutron dose rate was consistent at low energies between the three processing systems. At the higher proton energy and current settings the neutron dose rate values obtained by the three systems were still within error but a slight deviation was observed.