The Study Of ~9Li Cluster Stucture

In recent years,with the development of heavy ion accelerator technology and particle detection technology,the establishment and operation of radioactive nuclear beam devices,people can study the inner structure of the nucleus,especially the cluster structure of the nucleus.The phenomenon of cluster in nuclei is an important phenomenon in studying nuclear multi-body problems,and there are many stable nucleis have cluster structures,especially the neutron-rich nuclei and weakly-binding nuclei,and it inspire more and more people to pay attention to the structure of atomic nuclei.In recent years,cluster structures have been found in many unstable nucleus.At present,the experimental studies of cluster structure mainly focus on the light and drip line nucleus near N=Z.However,there are few studies on the cluster structure of radioactive nuclear bundles,of which?cluster structures are the most common.The cluster structures will form nuclei with different cluster shapes under different conditions.Through the investigation,it has been found that there are many studies on the structure of ⁹Li clusters in these years.Most of them are about theoretical calculations.From experimental aspects,⁹Limainly focuses on elastic scattering reactions,quasi-elastic scattering reactions,inelastic scattering reactions,and transfer reactions.The experimental study of cluster structure is basically absent.Through the investigation,we found that a cluster structure exists in the ⁹Li nucleus based on AMD theoretical model calculations.Due to analyzing of the data of ⁹Li breakup reaction,to find the ⁹Li cluster structure,we must calibrate all the detectors used in this experiment.The calibration of the detector is very important,and the calibration of the detector directly affects the later analysis of experimental data.The data analysis of this experiment is mainly based on the experimental data analysis of the ⁹Li fracture reaction.The calibration methods of TOF-?E detector system,parallel plate avalanche detector,double-sides silicon detector and CsI?Tl?array detector,and we mainly introducing these calibration methods.The experiment was completed on the RIBLL experiment terminal.The ¹²C main beam with an energy of 60MeV/u reacted on the primary target Be target to generate secondary fragments,which passed through the RIBLL.With the choice of two secondary magnets,a ⁹Li secondary beam of target energy can be acquired.The?E-TOF-B?detector system was used to identify the secondary beam particles,and after the secondary target,the PPAC detector was used to monitor the track of the secondary beam to determine the position information and direction information of the beam.The selected target secondary beam ⁹Li react on a natural secondary C target and its thickness is 1mm.A double-sides silicon strips detector with 16 silicon strips on positive and negative is placed behind the secondary target and an an array of CsI?Tl?crystal detectors which consists of 8×8 CsI?Tl?crystal covers the angle?from 0⁰ to10⁰.So we can identifies and measures the reaction product particles after the secondary target.The analysis of data obtained from the experiment is based on the ROOT software and depended on C++programming,combined with Lise++simulation.By reading each signal from each detector and selecting effective events,we can get rid of useless events,select appropriate events to analysis and process,and finally,we calibrate each detector used in the experiment.It laid a good foundation for the later data analysis of the ⁹Li experiment.