Device and method for CT (Computed Tomography) scanning of low-temperature sample

Abstract

The invention provides a device and a method for CT (Computed Tomography) scanning of a low-temperature sample and belongs to the technical field of non-destructive testing. The device is used for cooling a sample to be scanned in a closed X-ray shielding room to realize low-temperature fidelity of the sample. In order to reduce absorptive attenuation of X rays, liquid nitrogen which is easy to gasify at a room temperature and a room pressure is used as a refrigerating agent; a gasification spraying head is used for spraying the sample from top to bottom; the low temperature and a lot of gasification latent heat of the liquid nitrogen are utilized to realize refrigeration. The liquid nitrogen spraying power is gas pressure of a high-pressure nitrogen bottle and the refrigeration amount is controlled by liquid nitrogen spraying pressure and flow. In order to prevent the situation that the inner parts of an X-ray emission device and a CT room are dewed due to a great temperature difference, a semi-closed separation box is designed above a CT objective table and the liquid nitrogen is used for carrying out temperature control on the sample in the separation box; meanwhile, the gasified liquid nitrogen is discharged out of the CT room by a pipeline below the separation box. A vacuum heat-insulating pipe is adopted as a liquid nitrogen conveying pipeline so that the liquid nitrogen is not gasified in a conveying process and is prevented from being dewed.

Description

technical field [0001] The invention relates to a device and method for CT scanning of low-temperature samples, belonging to the technical field of non-destructive testing. Background technique [0002] X-ray CT (X-ray Computed Tomography) technology is a computerized tomography non-destructive testing technology. The X-rays are emitted by the X-ray generating device to penetrate the sample to be scanned, and the difference in the attenuation and absorption of X-rays by substances with different densities is used to calculate and process the ray intensity signal received by the ray receiving device through a computer to obtain the sample to be tested. Tomographic or 3D images. This technology has played a huge role in clinical diagnosis, internal structure analysis, non-destructive flaw detection and other fields. However, when performing structural analysis on some special samples that require a low-temperature environment, such as natural gas hydrate, a low-temperature e...

AI Technical Summary

Problems solved by technology

For X-ray CT scanning, liquid nitrogen also has the problem of affecting the imaging effect, and it cannot be adjusted for the temperature control range

At present, the liquid nitrogen spray refrigeration system suitable for X-ray CT equipment is still blank

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