Radiation Chemical Studies with Cyclotron Beams, (I)

Abstract

Systematic studies on the LET effect in the radiolysis of organic liquids have been initiated using various types of heavy ions accelerated by cyclotron. First, the effects of differences in irradiation conditions, in particular beam current, stirring speed and concentration of solutes have been examined. Aerated aqueous ferrous sulfate solutions (Fricke solutions) were subjected to irradiation by protons and He ions of various energies, to take advantage of the well-established reaction mechanism of the system. Experimental results obtained under various conditions were analyzed on the basis of the diffusion kinetics model. It was revealed that meticulous care must be taken to control the experimental conditions in studying radiolysis with heavy ions. The oxidation yields of ferrous ions were also determined as a function of linear energy transfer.

Chemical Dosimetry during Alpha Irradiation: A Specific System for UV-Vis <i>in Situ</i> Measurement

“…Moreover, the curve slope varies with the α beam intensity set down in the irradiation cell. These results are consistent with the literature data which take into account the intensity in the G(Fe 3+ ) determination [6]. These authors have shown that higher is the intensity higher is the G(Fe 3+ ) value.…”

“…It thus assumes that, under our experimental conditions, the use of a Faraday cup is quite satisfactory. The dependence of G(Fe 3+ ) with the energy of the α particles was already observed in the literature [6,8]. This dependence can be explained qualitatively by track theory.…”

“…This difference was already observed in the literature and could be explained, at least in part, like resulting from a better contribution of reaction (3) in the concentrated solution [6,8]. In our case, this can also be partially explained by a lack of experimental data for the lower doses.…”

“…The analysis of the literature data shows that, for an α radiation, no G(Fe 3+ ) value is available for energies higher than 40 MeV [3][4][5][6][7]9,10]. The Copyright © 2012 SciRes.…”

“…It is considered as reliable and easily to apply in many cases. However, in the case of α irradiation, the radiolytic yield of ferric ion (G(Fe 3+ )) value is studied in the literature for an ion beam energy value until 40 MeV [3][4][5][6][7][8][9] but the G (Fe 3+ ) values are unknown for higher energy. Since a few months, a new irradiation facility is available (Saint-Herblain, France): ARRONAX cyclotron, providing α and proton beams, with energy up to 67 MeV.…”