Collision site effect on the radiation dynamics of cytosine induced by proton  

作　　者：Xu Wang Zhi-Ping Wang Feng-Shou Zhang Chao-Yi Qian 王旭;王志萍;张丰收;钱超义(Department of Fundamental Courses,Wuxi Institute of Technology,Wuxi 214121,China;The Key Laboratory of Beam Technology and Material Modification of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China)

机构地区：[1]Department of Fundamental Courses,Wuxi Institute of Technology,Wuxi 214121,China [2]The Key Laboratory of Beam Technology and Material Modification of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China

出　　处：《Chinese Physics B》2022年第6期316-325,共10页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11905160 and 11635003);the‘333’Project of Jiangsu Province,China(Grant No.BRA2020327);the Science Foundation of Wuxi Institute of Technology(Grant No.ZK201903)。

摘　　要：By combing the time-dependent density functional calculations for electrons with molecular dynamics simulations for ions(TDDFT-MD)nonadiabatically in real time,we investigate the microscopic mechanism of collisions between cytosine and low-energy protons with incident energy ranging from 150 e V to 1000 e V.To explore the effects of the collision site and the proton incident energy on irradiation processes of cytosine,two collision sites are specially considered,which are N and O both acting as the proton receptors when forming hydrogen bonds with guanine.Not only the energy loss and the scattering angle of the projectile but also the electronic and ionic degrees of freedom of the target are identified.It is found that the energy loss of proton increases linearly with the increase of the incident energy in both situations,which are14.2%and 21.1%of the incident energy respectively.However,the scattering angles show different behaviors in these two situations when the incident kinetic energy increases.When proton collides with O,the scattering angle of proton is larger and the energy lost is more,while proton captures less electrons from O.The calculated fragment mass distribution shows the high counts of the fragment mass of 1,implying the production of H+fragment ion from cytosine even for proton with the incident energy lower than keV.Furthermore,the calculated results show that N on cytosine is easier to be combined with low-energy protons to form NH bonds than O.

关 键 词：time-dependent density functional theory CYTOSINE proton-induced collision FRAGMENTATION 

分 类 号：Q691[生物学—生物物理学]