Research On The Charge-transfer Of Multiply Charged Ions And Dynamics Of A Trapped Ultra-cold Ions

The study of the ion trap physics and its correlative technology has been the advanced topics of research. With its rapid development and its infiltration and extension in other correlative science, it can be applied in high-tech and basic study field, such as frequency standard, MCI collision processes and quantum information. In this dissertation, we studied the low-energy charge transfer of MCI in a RP trap experimentally and the dynamics of a trapped ultra-cold ion theoretically.First, we produced N²⁺ with e-gun in our ion trap mass spectrometry and study the charge transfer of N²⁺ and N₂, Consequently our experimental apparatus and its ability to measure charge transfer rate coefficient are tested. By laser ablation combined with the technology of crossed ion beams cooling, we produced and trapped selectively Sc³⁺ and Ti³⁺ in RF trap, with the mean energy about 4.15 eV and 4.43 eV respectively, their decay curve in the base vacuum are acquired. Moreover the charge transfer rate coefficient of Sc³⁺ with neutral molecules H₂ and N₂ is measured. To Sc³⁺ and H₂, the value is 1.44(0.39)×l0^-9cm³ ·s^-1 , while the value is 8.18(0.18)×10^-10cm³Â·s^-1 for Sc³⁺and N₂. These values are compared with the theoretical values of Langevin model, which are consistent in order of magnitude. These results can provide important data for the physical research area of fusion plasma and also serve as a testing ground for theory.A simple method is put forward to study the interaction of a trapped ultra-cold ion with laser without rotating wave approximation, in which Maxwell-Bloch equation is used. Firstly, the dynamics of a trapped ultra-cold ion in the standing laser is investigated within the Lamb-Dicke limit and weak excitation. We found there existed many non-period components in the ion motion, not rigid period oscillation under RWA. In the following, we studied the Raman interaction of a trapped ultra-cold ion with two traveling lasers without limitation of the Lamb-Dicke limit and weak excitation, the chaotic behavior of the system is shown in the wide range of the parameter. It is shown that the chaotic behavior is more and more pronounced with the increase of the Lamb-Dicke parameter and Rabi frequency, which is not essential to the detuning. At last, we study the dynamics difference of a trapped ultra-cold ion between the time-dependent potential and pseudo-potential in the absence of the requirement of Lamb-Dicke limit and RWA, where the micro-motion effect is considered. When Lamb-Dicke parameter and Rabi frequency is small, the...