Development Of Differential Vacuum System Used For Cluster Interaction And Study On The Mechanism Of Cluster Collisions

Study on the structure and physical properties of the clusters, is an important research subject of atomic and molecular physics. On micro clusters (atomic number from a few to tens) on the research of the structure and physical properties, whether in theory or has experiment obtained good results. However, for large scale clusters (atomic number reached a few thousand to twenty thousand) study, the results obtained are rarely. This is mainly because the number of large scale clusters of atoms is numerous, complicated structure, the theory also does not has the mature methods to describe the circumstances; Experiments, on the formation of gas phase of large scale clusters have been published, but the structure of large scale clusters and physical characteristics is rarely reported。This study proposes a new method:using micro clusters as a probe, and large scale cluster as a target, through interaction can get the structure and physical properties of indirect measurement of large scale clusters。The cluster micro ion experiment (H2+), through the gas phase of large scale clusters (Ar), for the collecting and analyzing collision products using electrostatic analyzer (mainly the energy spectrum analysis of proton). The experimental requirements for vacuum pumping system with gas velocity high pumping (produce, cluster target to jet will instantly lead to pressure chamber), and the target chamber with high vacuum stability. In order to achieve the above requirements, we designed a multistage differential vacuum system (acquisition and monitoring system with vacuum), and the vacuum system is tested, found that the test result is good, meet the cluster collision experiments. The cluster interaction mechanism research, introduced the plasma model (turbulence model in Plasma Physics), the micro clusters with large scale cluster interaction process theory, and gives the results of computer simulation and analysis.This paper is divided into four chapters, the first from the experimental device of telling, then elaborated the theoretical aspects.The first chapter, research status of the application of nuclear technology direction based on differential pumping system is introduced briefly, then the cluster physics research progress at home and abroad and the research history.The second chapter, firstly introduces the research objective differential pumping system, research methods, and the difference principle of system design. Secondly, described the structure characteristics of the multistage poor experimental design system, introduced the numerical differential vacuum measuring instruments and recording monitoring system of vacuum system. Finally, the differential vacuum system to practical test results are analyzed and discussed. Test results show that the numerical system, vacuum target chamber vacuum stable after about 10-4Pa, analog pulse injection process, target chamber vacuum recovery quickly and target chamber vacuum always changes within the needed range, the continuation of the system can ensure experiment, vacuum the differential system fully meets the requirements of the cluster collision experiment. The reason of difference numerical vacuum system vacuum end part changes to do the analysis, found the roots pump vacuum pump is lower than the limit of the molecular cause of vacuum fluctuations, some suggestions are proposed to improve the direction of the vacuum system.The third chapter introduces the basic concept of plasma, Coulomb explosion and description method. Found that the shock model in plasma physics, is very suitable for describing ion micro clusters through large scale cluster process large scale clusters in the outer electron to ion micro clusters. The mathematical formula of vibration model of the applicability of transformation, derived from the Coulomb explosion cases, expression of protons through the target in the process of stress conditions of mathematics. At the end of this chapter for large scale cluster physics experiment method are briefly described。Introduces the principle of micro clusters and large scale cluster interaction established theoretical model, can be used for the computer simulation of the process of the collision, the collision process is a mathematical description. The use of computer, the numerical calculation of theoretical model, the calculation results are analyzed and discussed. Theoretical calculation shows, in microcluster through large scale cluster process, both the strong interaction of protons, Coulomb explosion microcluster the spectrum response was split the wake effect.