Two-Dimensional Ultrafast X-ray Imager for Inertial Confinement Fusion Diagnosis

A two-dimensional ultrafast X-ray imager (UXI) composed of a time-dilation device, an electron-beam imaging unit, a gated microchannel plate (MCP) framing tube, and a pulser was developed. The time-dilation device extends the time spread of the electron signal generated by the pulsed photocathode (PC), and the electron-beam imaging unit images the electron pulse from PC to MCP. Finally, the gated MCP framing tube samples the dilated electron pulse. The time resolution and image size of the UXI were measured with an X-ray generated by a terawatt laser targeting device. When a driving pulse with a 2 V/ps slope is applied to the PC, the measured time resolution is 21 ps, and the image size is 12 mm x 3.9 mm. Furthermore, the image size varies with the time resolution. The results show that as the time resolution improves, the image size decreases. The use of two opposite-transmission PC driving pulses could improve the image size. Moreover, the measured UXI spatial resolution is 5 1p/mm, and the spatial resolution will be worse with the increasing off-axis distance.

Automated summary

A two-dimensional ultrafast X-ray imager (UXI) consisting of a time-dilation device, an electron-beam imaging unit, a gated microchannel plate (MCP) framing tube, and a pulser was developed. The UXI measured the time resolution and image size using an X-ray generated by a terawatt laser targeting device. The results showed that improving the time resolution decreased the image size, and using two opposite-transmission pulse driving pulses improved the image size. However, the spatial resolution worsened with increasing off-axis distance.