Long Pulse Krf Laser Acceleration Double Flyer

Equations of state (EOS) at high pressure is a fundamental subject to inertial confinement fusion (ICF), astrophysics, geophysics, materials science, space technology, weapon physics and other related fields. Since the birth of laser technology, high power laser system has been a new tool for EOS research. Many kinds of research have been taken up such as relative measurements (match-impedance method), absolute measurements, indirect or direct laser drive. This paper introduces the experimental research in double-layer flyer acceleration using a KrF laser system with a long pulse duration and a numerical simulation.In chapter one, an introduction about EOS study is given firstly, then, the history of the EOS research works is reviewed. laser's characteristic as a shock wave drive and the advantages of KrF laser are explained. Finally, the progress at home and abroad is enumerated.In chapter two, the basic principle of the EOS study is introduced. Specially, the impedance mismatch effect of the double-layer flyer is mentioned here. It is the primary theoretical basis of this paper.In chapter three, a one-dimension, three-temperature hydrodynamic code HYADES is introduced briefly. it is used to make a qualitative analysis about how the thickness of ablator affect the flyer velocities and stability.In chapter four, the experimental setup is described.In chapter five, the results of the experiments are analysed, we draw a conclusion that the thickness of ablator should try to reach the critical thickness.We deduce the formula of the critical thickness of ablator, and put forward the rule of how the thickness of ablator affect the velocities and the stability of flyer. Then, the numerical simulation is used to research it, and the same verdict is given. Finally, we test the velocities of three flyers with ablator of different thickness, the result indicates that we can measure the velocities of flyer which can further calculate the released particle velocities, and validate the verdict of theory and simulation. To improve the precision ofthe experiment, we should improve the stability of laser and make perfect the real-time inspection of the changes of the laser quality, otherwise we should improve the technics of the fabrication of the target.At last, the results of the theory, the numerical simulation and the experiments are summarized. It is concluded that the thickness of the ablator should try to reach the critical thickness.