Design And Implementation Of Precision Timing In PET System

High time resolution precision is one of the important indicators of the PositronEmission Tomography (PET). An improved scheme of constant fraction discriminatorelectronic circuit, which is responsible for temporal information extraction on theexisting PET’s coincidence system, is proposed by this thesis and the problem of lowtime resolution precision in the system has been resolved. The study has significantengineering application value.After carefully analyzing the development and the key constraint factors of thetime coincidence resolution for PET, the time readout system is designed to measuretime with high accuracy by combining FPGA and high speed ADC technique. Toachieve the golden, the main circuits, including analog circuit module, clock module,FPGA configure module, network transmission module, cPCI interface module and soon, are designed and the PCB layout is completed and the logic of FPGA is developed.High performance FPGA with the MAC core is used as the control device, andGigabit Ethernet and cPCI bus are used as the transmission media, realized theperformances of high speed acquisition, high precision time information acquisitionand data transmission, etc.The test shows that the time resolution of this time measurement scheme studiedby this thesis is720ps. So this design can meet the time measurement requirement forPET system.