Analyzing implosion symmetry based on fringe shifts of wide-angle velocity interferometer system for any reflector

A recording design of wide-angle velocity interferometer system for any reflector (VISAR) fringe that loading shaped optical fiber panel or ring-to-line fiber bundle in front of the streak camera is presented, and the coordinates of recording position are located at a certain circle on pellet. To realize implosion symmetry analysis, the phase of wide-angle VISAR fringes is obtained by using coordinate transformation, Fourier transformation and Legendre expansion, and its feasibility is verified by examples. The diagnostic characteristics, optical design, equipment development and data processing of the method are discussed, and the development direction of implosion symmetry diagnosis based on wide-angle VISAR is introduced. Using this method to record and analyze the wide-angle VISAR fringe data can make implosion symmetry diagnosis accurate, intuitive and vivid, and can provide support for studying laser plasma instability and fluid instability in inertial confinement fusion research.