TEPC gas gain measurements in propane.
Knowledge of the gas gain is important to optimise the design and the operating characteristics of tissue-equivalent proportional counters (TEPCs), especially for simulated sites smaller than 1 µm. TEPC area monitors of the order of centimetres must operate at very low gas pressure to simulate micrometric volumes, consequently the Townsend theory cannot be applied: effects related to the presence of an electric-field gradient become important and must be considered. A detailed description of the electron avalanche formation is complex, but in most practical cases an analytical formula can be used. The so-called gradient-field model includes three characteristic constants of the counting gas, which were already experimentally determined for propane-tissue equivalent (TE) and dimethyl ether (DME) gases. The aim of this work is to measure the gas-dependent parameters for propane gas. Preliminary results obtained with a spherical TEPC are presented.
Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy davide.moro@lnl.infn.it.
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Moro
Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy 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.
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Chiriotti
Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy.
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Colautti
Laboratori Nazionali di Legnaro, INFN-LNL, Legnaro, Italy.
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Conte
D002138:Calibration; D003198:Computer Simulation; D004583:Electrons; D004867:Equipment Design; D005740:Gases; D007700:Kinetics; D018499:Linear Energy Transfer; D008738:Methyl Ethers / Q000737:chemistry*; D009502:Neutrons; D011312:Pressure; D011407:Propane; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results
D005740:Gases; D008738:Methyl Ethers; C033413:dimethyl ether; D011407:Propane