摘要
In collisions between energetic highly charged ions and atoms,the ions could remove the electrons of the target atoms,or be excited into high-level states.In the first case,the target electrons not only be captured into ground and excited states of the projectile ions,but also be ionized to free.Non-radiative capture(NRC)and radiative electron capture(REC)are two competing mechanisms in fast collisions[1].NRC means electron transfer from a bound state of the target to a bound states of the projectile without the emission of radiation;REC is produced with simultaneous the emission of photon for satisfying energy and momentum conservation laws.The physical essence is the competition between the“electron-nucleus”interaction and the“electron-vacuum”interaction.NRC is dominant in collisions of high-Z ions with heavy target atoms at moderate energies.REC entirely determine the electron capture channel for high collision velocities and light targets[1].Measuring the relative strength of the projectile x-ray emission associated with electron capture could determine state-selective population,angular distribution of single capture Ly 1 or double capture Kα1 and Kα2,would provide new detailed information on the dynamics of ion-atom collisions and atomic structure studies[1].
