Study Of Hundred KeV/u H And Si Ions Interaction With Laser Produced Plasma

High energy density physics is one of the most advanced disciplines in today’s physics,which is closely related to hot fields such as astrophysics,inertial confinement fusion,weapon physics and high pressure new materials.Materials with high energy density generated by heavy ion beam drive have outstanding advantages such as large volume,uniform distribution,variety and precise state control,which provides a new opportunity for systematic experimental research.At present,high energy density physics research has attracted much attention.For example,FAIR facility in Germany and HIAF facility in China under construction both list ion beam driven high energy density physics research as one of the future core research contents.The physical process of the interaction between energy-carrying ions and dense plasma is one of the core problems in the production of high energy density matter driven by ion beam.The density distribution of ion energy deposition directly determines the state of the produced high energy density matter.Based on the comprehensive experiment platform of 320 k V highly charged ions,Institute of Modern Physics,Chinese Academy of Sciences,the following researches were carried out in this paper:（1）A new experimental measuring device for the interaction between ion beam and laser plasma in the 100 keV/u energy region has been established for the high precision study of ion energy loss and charge states.The experimental equipment includes:generation and control of pulsed ion beam（≥200 ns）,preparation of high density(10¹⁷～10²¹ cm^-3)laser plasma target,online diagnosis of laser plasma parameters,high resolution ion measurement system（<1%）,and timing control of experimental measurement.（2）In the new device,the energy loss of the proton beam in the laser Al plasma in the 100 keV/u energy region is measured,and the experimental results of the change of the proton energy loss with the initial energy of the shell ion are obtained.Considering that the coupling strength between the proton beam in the energy region and the plasma free electron under this experimental condition is about 0.2,which is still in the linear interaction region,theoretical models such as Bethe and SSM are used to explain the above experimental results,and it is found that the calculated value of Bethe theory is significantly lower than the experimental value.However,the calculated values of SSMmodel are in good agreement with the experimental results,indicating that the energy loss contribution of bound electrons and the modification of polarization effect should be considered in the incomplete ionized plasma.（3）In addition,the energy loss and charge state distribution of Si⁶⁺ions after passing through the laser Al plasma target of 28～60 keV/u were measured,and the information of energy loss of ions and the evolution of charge state distribution with the initial energy of cannonball ions was obtained.Using Kreussler and Gus’kov theoretical models,the effective charge values of cannonball ions are calculated respectively.A new beam target coupling factoris proposed,and a dividing line is found at5,i.e.5,the effective charge values calculated by Kreussler model and SSM energy loss model are suitable.5,the effective charge value calculated by Gus’kov model combined with SSM energy loss model is more suitable.According to the calculated capture and ionization cross sections,the variation of average charge states with energy is given,which is in good agreement with the experimental results.It is proved that when5,the non-radiative capture and double electron capture effect of shell ion are enhanced,which makes the capture cross section increase suddenly.The applicability of SSM model in beam target linear interaction region is also proved.In this work,an experimental device for interaction between ion beam and laser plasma was built,and high-precision experiments were carried out to measure the energy loss and charge state distribution information of ions in the 100 keV/u energy region in laser Al plasma target.Compared with the existing theoretical model of energy loss,it is found that the energy loss of bound electrons in the incomplete ionized plasma contributes more to the total energy loss.In addition,the polarization effect of the plasma target region also needs to be considered.In comparison with the existing effective charge theory,it is found that the effect of non-radiative capture of bound electrons in shell ions and plasmas on the charge states should be considered in the lower energy region.This study can provide high precision experimental data and technical guidance for the study of the interaction between highly charged ions and dense laser plasma in low energy region.