PDF《2017》

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4 Direct Observation of Interatomic Relaxation Processes in neon Dimers by Electron-impact Yan Shuncheng, Zhang Pengju, Shen Lili and Ma Xinwen We carry out an experimental investigation of Ne dimer fragmentation following a

380 eV electron impact. By detecting the Ne+ ?Ne+ cation pair and one of the emitted electrons in coincidence, the ?ngerprint of the interatomic Coulomb Decay (ICD)[1,2] process initiated by the innervalence ionization of Ne is obtained. It is also observed that most of the low-energy electrons resulting from reactions leading to the fragmentation of the neon dimers in two Ne+ ions are produced by the ICD[3] Fig. 1. Because the collision between an ionizing particle and the molecules comprising biological medium produce intermediate-energy secondary electrons [4] , and these electrons further collide with and ionize the molecules in the environment;

our results suggest that the ICD evoked by such a secondary electron is an e?cient source for low-energy electrons responsible for radiation damage. We also clari?ed that the radiative charge transfer (RCT) caused by the double ionization of Ne are the important relaxation mechanisms leading to the dimer fragmentation into Ne+ + Ne+ in the intermediate-energy electron-impact processes.