To design a low-noise high temporal resolution X-ray detector suitable for application in strong radiation environments, a new time dispersion compensation low-noise high-resolution X-ray imaging tube is proposed in this work. This tube is mainly composed of a photocathode, an acceleration electrode, an “S” type time dispersion compensation structure, and a microchannel plate (MCP) electron multiplier tube. By combining pulse modulation technology and an “S”-type time dispersion compensation structure, this tube can not only reduce time dispersion and improve temporal resolution, but also filter high-energy neutron noise, thereby achieving high signal-to-noise ratio detection of signals in strong radiation environments. The effect of pulse modulation voltage slope on time magnification is calculated, and the results show that the time amplification factor increases gradually with the increase of modulation signal slope (1–6 V/ps). This is mainly because when the slope of the modulated pulse signal increases, the rate of change in the electric field between the photocathode and the accelerating mesh increases, resulting in a difference in speed between the photoelectron pulses emitted from the mesh, and the time dispersion effect becomes more pronounced after the same drift length.

The theoretical results show that in the A -B section, with the increase of y, the temporal magnification gradually increases positively, and the uniformity is 7.86%. In the B -C section, with the increase of y, the changes of temporal magnification are minimal, and the uniformity is 1.75%, which realizes temporal dispersion compensation. The effect of the distance d between the MCP electron multiplier and the “S” type time dispersion compensation structure on the spatial magnification is simulated, and the results show that the spatial magnification increases almost linearly with d, making it adaptable to different sizes of MCPs. The effect of MCP working voltage on the electronic gain of X-ray imaging tube is simulated, and the results show that with the increase of MCP working voltage (700–1000 V), the electronic gain of the imaging tube increases sharply, up to 10⁴, but it is an order of magnitude lower than the result of single MCP gain simulation (10⁵), which is mainly attributed to the electromagnetic field distribution of the “S” type time dispersion compensation structure and can make the photoelectrons spiral, and the velocity of the photoelectrons when they reach the MCP input face is not perpendicular to the MCP input face. The new X-ray imaging tube can completely resolve photoelectrons at 5 ps intervals at different MCP operating voltages. Finally, the temporal resolution of photoelectron output pulses at the anode is investigated at an MCP operating voltage of 800 V. The results indicate that the ultimate temporal resolution of the X-ray imaging device is 2 ps. The low-noise and high temporal resolution X-ray imaging tube designed in this work has the following advantages: high temporal resolution, low noise, high signal-to-noise ratio, and large dynamic range, and is expected to be used in strong radiation environments such as inertial confinement nuclear fusion to achieve high-quality diagnosis of ultrafast light pulses.