Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy-ion irradiation

Moribayashi, Kengo

We theoretically study the DNA damage due to the effect of the composite electric field of HO ions produced from the irradiation of a C ion with the energies of a few MeV/u and a proton with the energy of a few 100 keV/u to 1 MeV/u. We develop a new model for heavy particle irradiation in order to treat this composite electric field. We have found that the number of electrons trapped in the composite electric field depends on the cross sections of heavy particle impact ionization. We have also found that a larger number of electrons is produced due to the existence of the composite electric fields in the case of the irradiation of a C ion with the energies of a few MeV/u. This may promote the DNA damage, in particular, cluster DNA damage. The models given in this paper are also important in atomic and molecular elementary processes in electric fields and in the production of plasmas due to heavy particle irradiation.