Acquisition of non-vibration ICF cryogenic target interference pattern

In characterizing the fuel layer in ICF cryogenic target by the interferometry, it is inevitable that the target vibrates due to the vibration of the mechanically-cooling and vacuum-pumping system. This leads to different interference patterns of the cryotarget with different states at different times, which is called the interferogram vibration. A method based on the digitalimage-processing technology to eliminate this vibration is introduced. By capturing the position and interference images simultaneously by two identical CCDs, the position image is used to determine the vibration degree of targets for processing the interference at a defined state. Four algorithms, frequency estimation, projection demarcation, feature match, and full match are developed to determine the position of the target. The corresponding digital-image-processing methods, instead of upgrading the system hardware, which can largely improve the experimental results from the interference pattern, are introduced. (authors)