| Zugriffsnummer | 15070 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Ionization-cluster distributions of α-particles in nanometric volumes of propane: measurement and calculation |
| Autor(in); Institution |
De Nardo, L.; University of Padova, Physics Department, Padova, ITALY
Colautti, P.; INFN Laboratori Nazionali di Legnaro, Legnaro, Padova, ITALY
Conte, V.; INFN Laboratori Nazionali di Legnaro, Legnaro, Padova, ITALY
Baek, Woon Yong; 6.002, Grundlagen der Dosimetrie, PTB-Braunschweig
Großwendt, Bernd; 6.002, Grundlagen der Dosimetrie, PTB-Braunschweig
Tornielli, G.; University of Padova, Physics Department, Padova, ITALY
|
| Quelle/Jahr | Radiation and Environmental Biophysics: 42 (2002), 235 - 256 |
| ISSN | 0301-634X |
| Verlag | Berlin [u.a.]: Springer |
| Freie Schlagworte | Track structure of 5,4 MeV α-particles in propane ; structural microdosimetry ; formation of ionization clusters |
| Zusammenfassung | The probability of the formation of ionization clusters by primary α-particles at 5.4 MeV in nanometric volumes of propane was studied experimentally and by Monte Carlo simulation, as a function of the distance of the centre line of the particle beam from the target volume. The volumes were of cylindrical shape, 3.7 mm in diameter and height. As the investigations were performed at gas pressures of 300 Pa and 350 Pa, the dimensions of the target volume were equivalent to 20.6 nm or 24.0 nm in a material of density 1.0 g/cm3 The dependence of ionization-cluster formation on distance was studied up to values equivalent to about 70 nm. To validate the measurements, a Monte Carlo code was developed which allows the experimental arrangement and the interactions of α-particles and secondary electrons in the counter gas to be properly simulated. Apart from a mathematical formulation of cluster- size formation in nanometric targets, the main results of our study are (i) that the mean ionization cluster size in the δ-electron cloud of an α-particle track segment decreases as a function of the distance of the centre line of the α-particle beam from the centre of the SV with the power of 2.6, and (ii) that the mean cluster size and the ionization quality of a δ-electron are invariant at distances greater than about 20 nm. We expect that the ionization-cluster formation in nanometric gaseous volumes will in future provide the basis for the radiation quality in the field of radiation monitoring and radiation action theory. |
