| Zugriffsnummer | 11536 |
| Dokumenttyp | Bericht |
| Sprache | Englisch |
| Titel | Working Package 2: Basic physical data in organic gases: total electron scattering cross sections |
| Autor(in); Institution |
Großwendt, Bernd; 6.24, Strahlungstransportgrößen, PTB-Braunschweig
Baek, Woon Yong; 6.24, Strahlungstransportgrößen, PTB-Braunschweig
Henne, Ulrich; 6.24, Strahlungstransportgrößen, PTB-Braunschweig
|
| Quelle/Jahr | Quality assessment based on physical radiation interaction at nanometre level : MID-term report:(1999), 19 - 32 |
| Schriftenreihe | LNL-INFN report: 140 |
| Herausgeber(in) |
Colautti, P.; INFN, Laboratori Nazionali di Legnaro, ITALY
|
| Berichtsnummer | LNL-INFN-REP-140 |
| Verlag | Legnaro, Padova: LNL |
| Zusammenfassung | Total electron cross sections for the molecules of tissue-equivalent gases are of great interest for purposes of track structure analysis in the fields of microdosimetry or nanodosimetry. Here, comprehensive and more accurate measurements are necessary since the known sets of total cross sections either show large deviations among each other or are strongly restricted with respect to the energy range. It was, therefore, the aim of the present work to measure the absolute total scattering cross sections of electrons in the energy range between a few eV and a few keV in molecular nitrogen, carbon dioxide, methane and propane, which are the constituents of the most frequently used tissue-equivalent gas mixtures, and, in addition, also in dimethylether (DME), which might be of interest in the future as tissue-equivalent filling gas in low-pressure proportional-counter experiments. The total electron scattering cross sections were determined by measuring the attenuation of a narrow electron beam at a particular energy as a function of the number density of molecules in a scattering chamber of well defined dimensions using Beer's law but also taking into account the reduction of the attenuation by electrons scattered in the forward direction. The results, which have uncertainties of the order of 1.5%, are given in tabular form. Their comparison with previously published total cross sections showed that the latter are too small by about 10%, at energies greater than 1.0 keV. A detailed analysis of the experimental arrangements used for their determination proved that the rather large deviations were caused in part by an insufficient energy resolution of the measuring devices used by other authors and in part by an inadequate correction of the contribution of electrons scattered elastically in the forward direction. |
| Rechteinformation | 1999, I.N.F.N. |