Enhanced damage induced by secondary high-energy electrons

Abstract

A new kind of radiotherapy scheme based on the resonant Auger-interatomic Coulombic decay mechanism (RA ICD) was proposed in the work of Gokhberg et al. [Nature 505, 661 (2014)], which may effectively reduce the overall radiation dose in traditional x-ray radiotherapy. An electron produced in this scheme carries most of the energy of the primary x-ray photon. Through the present experiment using an energetic electron impact on a NeAr dimer, we demonstrate that three processes, namely, the interatomic Coulombic decay triggered by a Ne 2s electron ionization, ICD triggered by Ar+* (3p(4)nl >= 5d), and charge transfer in the Ar2+ Ne ion, can take place and enhance the yields of slow electrons and ions. Therefore, energetic secondary electrons make the x-ray RA ICD scheme more toxic in radiotherapy.