The Design Of Dual-mode Readout Electronics System Based On Silicon Drift Detector And Scintillation Crystal

Gamma-ray bursts are a phenomenon in which the intensity of gamma-rays in a certain direction instantaneously increases and then decreases rapidly in the process of stellar-level celestial explosions on the cosmological scale,revealing the origin of cosmological distances.And now,the detection of gamma-ray bursts is one of the most active directions of current astronomical research.There are two core requirements for gamma ray detection,one is to improve the position resolution capability on the premise of ensuring a larger field of view,and the other is to improve the energy resolution capability.The improvement of these detection requirements has made the gamma-ray detection technology gradually evolve towards a large-scale and high-integration direction,which also puts forward new requirements for the matching readout electronics.In this paper,a dual-mode readout electronics system based on scintillation crystals and silicon drift detectors is designed.The whole electronic system consists of two sub-systems.One is the position readout electronics system matched with the largearea scintillation crystal detector array.The other is an energy readout electronics system matched to a silicon drift detector.The simultaneous monitoring of the two can take into account the effective area,angular resolution and energy resolution of gammaray burst observations.The main research contents and work of the thesis are as follows:1.Design and implementation of position readout electronics:The readout electronics system is designed and optimized for a large-area biplane high-resolution position detector composed of a scintillation crystal array and a silicon photomultiplier(Si PM).The preamplifier is designed according to the output characteristics of the silicon photomultiplier tube;the threshold circuit is designed to ensure the accuracy of the detection information and the requirement of screening the trigger signal,and the analog-to-digital conversion circuit is designed according to the digitization requirements;ZYNQ is selected as the single-plane readout Control the processing center,detect the status of each channel unit on the plane at the same time,and report the real trigger events in the form of custom frame format data packets through the high-speed Ethernet interface;according to the characteristics of the silicon photomultiplier tube The silicon photomultiplier tube bias voltage is fine-tuned according to the ambient temperature to ensure stable gain.In order to solve the problem of dual-plane clock synchronization,a clock synchronization control circuit is designed,which provides synchronous clocks for the two-layer detection planes,and realizes synchronous start-stop control for the two-layer detection planes at the same time according to the instructions of the host computer.After the development of the position readout system,sufficient experimental tests have been carried out.The test results show that the position detection resolution is2cm2,the detection area is 1m2,the trigger resolution is 3.2n C,the minimum bias voltage adjustment is 10 m V,and the number of readout channels is 400 channels..Improved ray position resolution.2.Design and implementation of energy readout electronics:In view of the small size and many readout channels of silicon drift detectors,advanced application specific integrated circuit(ASIC)chips are used to replace traditional discrete components,and a readout electronics with ASIC+ZYNQ as the core is designed and produced.System,including hardware circuit implementation and ASIC drive logic design.Accurate collection of 32-channel energy signals is achieved,and the collected data is uploaded through the high-speed Ethernet interface.After the development of the energy readout system,sufficient experimental tests have been carried out.The test results show that the readout system can realize the readout of detector signals from 0 to 50 f C,the energy resolution is 0.1f C,the noise baseline of each channel is 50 m V,and the integral non-The linearity is better than 4%,and the channel consistency is good.The system has excellent energy detection capability.