X-Ray Imager With a 20 mm Width Microstrip Line for the Extreme Ultraviolet Spectrometer

A time-resolved x-ray imager based on the gated microchannel plate (MCP) technology is reported. The single MCP microstrip line with a width of 20 mm is formed to improve the spatial resolving capability. The microstrip line cathode coated on the MCP is driven by four gating pulses simultaneously. Each gating pulse has an amplitude of −1.7 kV and a width of 160 ps. The temporal resolution of the imager is demonstrated by utilizing an ultraviolet (UV) laser pulse and a fiber bunch optics. A measured temporal resolution of 68 ps is achieved, while the photocathode is applied with the four gating pulses plus a -200 V DC bias. Moreover, the gain uniformity of the imager is charactered at the Shenguang-III (SG-III) laser facility. An x-ray with 3 ns width is used to irradiate the microstrip line cathode uniformly. Then, the gating pulses travel along the microstrip line cathode with a gradually reduced amplitude, which lead to a decreasing gain. The measured results show that the MCP gain is dropped to 30% along the gating pulse traveling direction, and a perpendicular gain variation of 4% is obtained.