Design Of High Spatial Resolution Autoradiography Detector Based On SiPM/Scintillation Crystal Array

Autoradiography is a nuclear imaging apparatus that uses an image of a beta or gamma ray emitted by a radionuclide,which is detected by a nuclear detector and subjected to development,fixing to form an image.It can accurately measures the distribution and quantity of radiotracers.It is based on 2D slice imaging of cells or tissues.The spatial resolution of positron emission autoradiography can reach hundreds of micrometers,which can more accurately judge the distribution of tracer and activity concentration distribution.PET is an order of magnitude higher spatial resolution and is known as the"gold standard"for detecting metabolic distribution.This study aims to introduce the leading edge technology of PET detectors such as Silicon Photomultipliers(SiPM)coupled scintillation crystal detector structure,signal multiplexing method and MVT digitization method into the autoradiography detector to enhance radiation.The sensitivity and spatial resolution of the self-developing instrument,and the detector mode of the inorganic scintillation crystal coupled optoelectronic device were further studied while developing the detector for the autoradiography instrument.In this paper,a high-resolution autoradiography detector is designed using a new photoelectric conversion device—SiPM and digital scintillation pulse acquisition technology.Compared with traditional instruments,the crystal array-coupled SiPM detector design has higher sensitivity,and due to the high gain of the SiPM device,it has the advantage of detecting high-energy gamma photons and more suitable for positron autoradiography.This design introduces multi-threshold voltage pulse sampling method based on prior information and multi-channel multiplexing technology of SiPM into the detector,and completes the digital acquisition system of pulse.In this paper,the electronic design of SiPM detector based on 3mm×3mm~2 and 1mm×1mm~2 effective area is completed.The optimal detector electronic performance environment is determined by evaluating the detector position spectrum quality information:temperature 5°C,SiPM bias voltage 30V,overflow rate 10%@1V.Using a SiPM array with an effective area of 3mm×3mm~2 and an 18×18 inorganic scintillation crystal array,the detector design with an internal spatial resolution of 0.6mm is completed.The detector-level energy resolution can reach 14.6%,which is consistent with the time resolution of 978ps@350keV-650keV,the position spectrum is clearly visible.On this basis,an ultra-fine YSO crystal array with a single crystal size of 0.5mm×0.5mm was introduced,and a 1mm×1mm2 SiPM array was coupled to design the spatial resolution of the detector.After further exploration,macroscopic autoradiography experimental spatial resolution can be achieved...