A gated microchannel plate soft X-ray imaging system for a laser plasma experiment

A picosecond soft X-ray imaging system for a laser plasma experiment which is convenient for practical use is developed. The system, based on a gated microchannel plate (MCP) with four 6-mm-wide stripline cathodes is capable of capturing multiframe soft X-ray images at time resolution of 60-100 ps and spatial resolution of 15 lp/mm. During design and construction of the system, emphasis was placed on reliability and operating convenience. The four gating pulses for each stripline were generated by a single avalanche transistor circuit, ensuring a steady time sequence and the same waveform for each pulse. The transmission characteristics of the four striplines were adjusted to be identical by monitoring the time domain reflectometry (TDR) of each stripline. The construction of the pulser and striplines in this manner allowed for both timing and sensitivity consistency of the gating for the four striplines. A pinhole system was equipped in front of the imager with precise control and flexible pinhole illumination, making the alignment and adjustment of the pinhole array very easy. The system was used in a high-power laser plasma experiment and results were obtained both with the pinhole and pinhole grating array.