Alpha-particle fluence in radiobiological experiments.
Two methods were proposed for determining alpha-particle fluence for radiobiological experiments. The first involved calculating the probabilities of hitting the target for alpha particles emitted from a source through Monte Carlo simulations, which when multiplied by the activity of the source gave the fluence at the target. The second relied on the number of chemically etched alpha-particle tracks developed on a solid-state nuclear track detector (SSNTD) that was irradiated by an alpha-particle source. The etching efficiencies (defined as percentages of latent tracks created by alpha particles from the source that could develop to become visible tracks upon chemical etching) were computed through Monte Carlo simulations, which when multiplied by the experimentally counted number of visible tracks would also give the fluence at the target. We studied alpha particles with an energy of 5.486 MeV emitted from an 241Am source, and considered the alpha-particle tracks developed on polyallyldiglycol carbonate film, which is a common SSNTD. Our results showed that the etching efficiencies were equal to one for source-film distances of from 0.6 to 3.5 cm for a circular film of radius of 1 cm, and for source-film distances of from 1 to 3 cm for circular film of radius of 2 cm. For circular film with a radius of 3 cm, the etching efficiencies never reached 1. On the other hand, the hit probability decreased monotonically with increase in the source-target distance, and fell to zero when the source-target distance was larger than the particle range in air.
Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong.|Faculty of Science, University of Kragujevac, Kragujevac, Serbia.
Dragoslav
D
Nikezic
Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong.|State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong.
Kwan Ngok
KN
Yu
D000512:Alpha Particles; D006018:Glycols / Q000737:chemistry; D055620:Optical Phenomena; D011336:Probability; D011853:Radiobiology
D006018:Glycols; C013925:diallyl glycol carbonate
CR-39; PADC; SSNTD; alpha particle; fluence; solid-sate nuclear track detector