Method for lowering detecting dose of radiation imaging system

Abstract

The invention discloses a method for lowering detecting dose of a radiation imaging system. The system comprises a ray source, a front collimator and an array detector, wherein a detecting channel for passing through a to-be-detected object is formed between the front collimator and the array detector; the front collimator is used for collimating rays emitted by the ray source into a sheet fan-shaped beam; the sheet fan-shaped beam penetrates through the detecting channel and then is received and imaged through the array detector; the width of a complete shadow area of the sheet fan-shaped beam, when the sheet fan-shaped beam reaches an incident window of each detector in the corresponding array detector, is matched with the width of the ray incident window of the detector. The width of the incident window area of the sheet fan-shaped beam is matched with the width of the ray incident window of the detector through the front collimator, so that not only can the rays of the complete shadow area be effectively utilized to scan and image, reduce useless rays entering the detector and guarantee the image quality, but also the quantity of rays radiated on the detected object can be reduced as much as possible to lower the detecting dose.

Description

technical field [0001] The invention belongs to the field of nuclear technology applications, and specifically relates to a method for reducing the detection dose of transmission radiation imaging systems widely used in customs, airports, wharves, stations, road checkpoints, etc., for goods, trucks, containers, etc. at present. Background technique [0002] Radiation imaging detection systems for goods, trucks, containers, etc. at customs, airports, docks, and stations are usually composed of a ray source, a front collimator, a rear collimator, and a detector. The rays emitted by the ray source pass through the front collimator After being collimated into a sheet fan beam, it passes through the object to be inspected in the detection channel and is received and imaged by the array detector. In order to ensure that the detector can receive radiation reliably, the thickness of the sheet fan beam is often much larger than the width of the detector’s incident window For this...

AI Technical Summary

Problems solved by technology

[0003] Due to the large thickness of the sheet-like rays passing through the detection channel, the detection dose is relatively large. Therefore, when this detection system is working, the personnel on the vehicle must get off the vehicle and pass outside the detection channel, and the vehicle is dragged by the traction mechanism or dragging device. In the detection channel, or when the vehicle is not moving, the detection gantry straddles the vehicle and sweeps over the inspected vehicle. The detection speed is generally 6-18m / min, that is, 0.36-1.08km / h, and the pass rate is about 10-30 vehicles / h, the detection efficiency is low, and the dragging device or door frame guide rail is required, and the equipment is complicated

At the same time, it is also necessary to set up a special rear collimator, and the radiation safety control area on both sides of the gantry is relatively large, and a radiation safety protection structure needs to be added, which further increases the complexity of the equipment and the processing cost

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