A gamma ray time detection device and its detector manufacturing method

Abstract

The invention discloses a gamma ray time measurement device and a method for manufacturing the detector thereof. The device comprises: a detector, a timing discrimination circuit, an amplification and shaping circuit, a single-channel pulse analyzer, a delay circuit, a time-amplitude conversion circuit, and a coincidence circuit and multi-channel analyzers. The present invention uses BaF2 crystal, POPOP, and silicone rubber as materials to make a composite scintillator with a special process, and process it into a honeycomb shape to form a detector, which can convert the fluorescence of 220nm wavelength emitted by BaF2 crystal into visible light with a wavelength of about 420nm, without A photomultiplier tube with a quartz window is needed, which greatly expands its application range; the structural design of the honeycomb shape increases the surface area of ​​the scintillator, so that part of the scintillation light can propagate in the air medium and reach the photodetector after refraction. The time of the photodetection device is shortened, so that the initial stage of the signal rises faster, which is beneficial to the timing of the timing discriminator, thereby improving the timing accuracy of the gamma ray time measuring device.

Description

technical field [0001] The invention belongs to the technical field of radiation detection, and in particular relates to a gamma ray time detection device and a method for manufacturing the detector. Background technique [0002] The time measurement of γ-rays is an important aspect of radiation detection technology, which can be used in many fields such as positron annihilation lifetime measurement and positron tomography. [0003] The usual time measurement method is to use a time detector composed of a plastic scintillator coupled with a photomultiplier tube to measure time. The luminescence decay time of the fast-response plastic scintillator is on the order of 1ns, which has excellent time resolution performance and can also match a variety of silicon A variety of photoelectric conversion devices such as boron glass photomultiplier tubes, photodiodes, and avalanche diodes form a time detector. However, due to the low atomic number of the time detector, the stopping pow...

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Problems solved by technology

BaF 2 The fast luminescent component of the crystal is in the ultraviolet band, which does not match with many photoelectric conversion devices (such as photodiodes, avalanche diodes, silicon photomultiplier tubes, and borosilicate glass photomultiplier tubes), so they cannot be used with these devices to form time detectors, such as The sensitive waveband of borosilicate glass photomultiplier tube Hamamatsu R9800 is from 300nm to 650nm, and its peak is at 420nm. For BaF 2 The luminescent fast component of the crystal hardly responds, so BaF cannot be used 2 Crystal and Hamamatsu R9800 photomultiplier tube form a high-performance time detector

There are very few types of photomultiplier tubes for quartz windows, the price is expensive, and the volume is much larger than that of photodiodes, avalanche diodes, and silicon photomultiplier tubes. These are problems that affect their widespread use.

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