Primary radicals production from water fragmentation by heavy ions

Abstract

The importance of fragmentation of water molecules by heavy ions is discussed for several different physical environments, including tumor treatment, planetary sciences and fi ssion reactors. The characteristics of the fragmentation yields by electrons, protons and photons are presented and compared with fragmentation yields of water molecules by C 3+ and O 5+ ions at energies corresponding to the Bragg peak. It is shown that for low energy electron loss and high energy electron capture, the water molecules essentially blow-out, releasing a much larger fraction of O q+ ions as compared with electrons, protons and photons.

Free-electron production from nucleotides upon collision with charged carbon ions

“…5(c), thereby further implicating the location of the Bragg peak to be around 0. study. The deviations in the present results are likely due to the fact that the nucleotide pair is not a continuous medium, as opposed to the earlier assumptions [27], where the bulk water was investigated. The difference in the total charge of the projectile is also affecting the discrepancies between earlier estimates and the present result.…”

“…The effective interaction distance between the C 4+ ion and the CYT+GUA pair used to compute the stopping power of the C 4+ ion is estimated to be x eff = 2 ± 0.5Å based on the van der Waals radius for atoms being 1-2Å. Figure 7 shows that the stopping power obtained from simulations peaks at ∼0.12 MeV/u, indicated by the blue arrow, thereby differing by a factor of 2 compared to the curve measured in bulk water [27], for which the peak is around ∼0.24 MeV/u as indicated by the orange arrow. The comparison of the two curves suggests that they are shifted one with respect to another, overestimating the stopping power of lower kinetic energies as compared to a previous result [27] but otherwise reproducing the same trend.…”

“…The net release of electrons after the collision seems to depend on the initial kinetic energy, and similarly for the impact parameter; see also the supporting video S4 in the SM [25]. Comparison of the stopping power of the C 4+ ion in the CYT+GUA pair collisions (squares) with the stopping power of C 3+ ion in water (orange line) [27]. The effective interaction distance of the C 4+ ion with the CYT+GUA pair is assumed to be 2 ± 0.5Å based on the van der Waals radius, leading to a spread out distribution highlighted by a green color.…”

Radiation influence on the temperature-dependent parameters of fluids

“…Over the past few decades numerous studies of the influence of irradiation on different physical systems have appeared in the literature [1][2][3][4][5]. In most of the papers devoted to the physical mechanisms involved in the interaction the solid state is concerned [6][7][8][9], but only few of them are devoted to studies of the physical mechanisms the irradiation affects the liquid matter.…”