title: Equivalence of pure propane and propane TE gases for microdosimetric measurements.
abstract: A tissue-equivalent proportional counter (TEPC) simulates micrometric volumes of tissue if the energy deposited in the counter cavity is the same as that in the tissue volume. Nevertheless, a TEPC measures only the ionisations created in the gas, which are later converted into imparted energy. Therefore, the equivalence of the simulated diameter (Dρ) in two gases should be based on the equality of the mean number of ions pairs in the gas rather than on the imparted energy. Propane-based tissue-equivalent gas is the most commonly used gas mixture at present, but it has the drawback that its composition may change with time. From this point of view, the use of pure propane offers practical advantages: higher gas gain and longer stability. In this work, microdosimetric measurements performed with pure propane, at site sizes 0.05 mg cm(-2) ≤ Dρ ≤ 0.3 mg cm(-2), demonstrate that the response of a propane-filled detector in gamma and in neutron fields is almost the same if an appropriate gas density is used.
authors.affiliation: Belgian Nuclear Research Centre, SCK•CEN, Mol, Belgium Center of Molecular Imaging, Radiotherapy and Oncology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain (UCL), Brussels, Belgium Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy scalvare@sckcen.be.
authors.forename: S
authors.initials: S
authors.lastname: Chiriotti
authors.affiliation: Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Moro
authors.affiliation: Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Colautti
authors.affiliation: Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Conte
authors.affiliation: Guest at LNL-INFN, Legnaro, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Grosswendt
mesh_terms: D002138:Calibration; D003198:Computer Simulation; D055616:Microtechnology / Q000379:methods*; D009502:Neutrons; D011407:Propane / Q000032:analysis* / Q000737:chemistry*; D011522:Protons; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*
chemical_list: D011522:Protons; D011407:Propane