Microchannel plate-based modulated X-ray generation device and method

Abstract

The invention discloses a microchannel plate-based modulated X-ray generation device and method. The microchannel plate-based modulated X-ray generation device comprises a photocathode, a microchannelplate, two mesh electrodes, an anode target, a vacuum system and a high-voltage power supply, wherein a front plate and a back plate of the microchannel plate provide deflection voltage; the back plate of the microchannel plate and one mesh electrode form a field-free region; the mesh electrode and the other mesh electrode form an uniform electric field; the anode target is used for bombarding electrons accelerated by the uniform electric field and then generating X-rays; the photocathode, the microchannel plate, the mesh electrodes and the anode target are arranged in the vacuum system; thehigh-voltage power supply provides the microchannel plate, the mesh electrodes and the anode target with electricity; and modulation of the X-rays is achieved through adjusting the deflection voltage,the uniform electric field and voltage of the anode target. According to the microchannel plate-based modulated X-ray generation device and method, large-area array modulated X-rays with large dynamic ranges and uniform photon flux density can be generated.

Description

technical field [0001] The invention relates to the fields of precision opto-mechanical and aerospace technologies, in particular to a modulating X-ray generating device based on a micro-channel plate. Background technique [0002] In the research of X-ray single-photon coincidence measurement technology, high-precision time and position of X-rays are simultaneously measured by multi-channel position-sensitive X-ray single-photon detectors. In order to test and calibrate the performance indicators of this type of X-ray single-photon detector, it is required that the test and calibration equipment has the ability of large-area X-ray radiation with large dynamic range, high time resolution, and uniform photon flux density. [0003] In order to test and calibrate the technical indicators of multi-channel position-sensitive X-ray single-photon detectors in the ground laboratory, verify the key technology of multi-channel position-sensitive X-ray single-photon detectors, and test...

AI Technical Summary

Problems solved by technology

The mechanical modulation method uses the modulation disc to realize the modulation of the X-ray intensity, the achievable output pulse frequency range and its stability are limited, and the time resolution is also poor; the grid modulation method is based on the traditional cathode and anode X-ray tubes. On the basis, increasing the modulation grid to control the number of electrons bombarding the metal target can realize pulse modulation X-ray with high stability. However, the output power has no linear relationship with the modulation voltage, and the time resolution is not good enough. X-ray Irradiation area and uniformity are poor

Neither of these two modulation methods is suitable for large area array X-ray radiation with large dynamic range, high time resolution, and uniform photon flux density.

[0006] In addition, there is a commonly used X-ray generation method using a photocathode as an electron emission source. Due to the low quantum efficiency of the photocathode, the X-ray intensity generated is limited.

At present, the quantum efficiency can be improved by using multi-alkali photocathode, but this type of photocathode has a short life, and requires ultra-high vacuum packaging, cannot be exposed to air, generally cannot be replaced, and is not suitable for generating X-ray radiation with large arrays

[0007] In the ground test and calibration test of the multi-channel position-sensitive X-ray single-photon detector, the diameter of the multi-channel position-sensitive X-ray single-photon detector is 50cm, the time resolution is 40ns, the energy detection range is 0.3-1.5keV, and it can detect The position and time of X-rays are measured at the same time. It is difficult to generate such large-area X-ray radiation with such a large dynamic range, high time resolution, and uniform photon flux density based on traditional filament cathode or photocathode X-ray generation methods.

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