本文介绍一种新型的位置读出方法,用于开发高分辨的小型伽玛相机。该伽玛相机采用小单元的CsI(Na)晶体阵列与位置灵敏光电倍增管(PSPMT)结合的探测器。其位置读出电路的设计把常规的阻抗电荷分配法与多路单通道直接读出法的优点结合在一...本文介绍一种新型的位置读出方法,用于开发高分辨的小型伽玛相机。该伽玛相机采用小单元的CsI(Na)晶体阵列与位置灵敏光电倍增管(PSPMT)结合的探测器。其位置读出电路的设计把常规的阻抗电荷分配法与多路单通道直接读出法的优点结合在一起,由硬件实现局域重心法(Truncated center of gravity)计算读出的位置,取得很好的效果。该伽玛相机的内在分辨率接近1mm,视野(FOV)达探测器的灵敏范围。这种新型的位置读出方法也可用于更高集成度的多阳极的位置灵敏光电倍增管的位置读出。展开更多
A new signal readout method for position-sensitive multi-output detectors,such as those in high-energy spectroscopy measurement and nuclear imaging,was developed by combining the charge division circuit,summing circui...A new signal readout method for position-sensitive multi-output detectors,such as those in high-energy spectroscopy measurement and nuclear imaging,was developed by combining the charge division circuit,summing circuit and charge-to-time conversion(QTC) circuit.The 64 outputs of a Hamamatsu H8500 position-sensitive photomultiplier tube were processed,and three digital pulses were generated.The widths of digital pulses were determined using the time-to-digital converter in an field programmable gate array.The energy and position information of incident y-rays is estimated based on the proportionality between the width of digital pulses and input charge created by y-photons.A prototype was built using discrete components and tested,and the energy and position resolutions were improved compared with that obtained with standard ADCs.This method greatly simplifies the front-end electronics and the digital interface.It enables a compact electronics system and an easy integration into an ASIC.展开更多
The 64 channel flat-panel position-sensitive photomultiplier tube H8500 (manufactured by Hamamatsu) is widely applied to various small and large array detection equipments. It has 12 stages of metal channel dynodes an...The 64 channel flat-panel position-sensitive photomultiplier tube H8500 (manufactured by Hamamatsu) is widely applied to various small and large array detection equipments. It has 12 stages of metal channel dynodes and a single common anode with the total effective area of 49×49 mm2. Each channel has the area of 5.9×5.9 mm2. In order to reduce the cost of the electronics, a predigested readout technique, DPC circuit for processing the signals from 64 channels was developed for our Micro-PET and PET.展开更多
文摘本文介绍一种新型的位置读出方法,用于开发高分辨的小型伽玛相机。该伽玛相机采用小单元的CsI(Na)晶体阵列与位置灵敏光电倍增管(PSPMT)结合的探测器。其位置读出电路的设计把常规的阻抗电荷分配法与多路单通道直接读出法的优点结合在一起,由硬件实现局域重心法(Truncated center of gravity)计算读出的位置,取得很好的效果。该伽玛相机的内在分辨率接近1mm,视野(FOV)达探测器的灵敏范围。这种新型的位置读出方法也可用于更高集成度的多阳极的位置灵敏光电倍增管的位置读出。
基金supported by the National Key Scientific Instrument and Equipment Development Project(No.2011YQ120096)National Instrumentation Program(No.2013YQ030629)the National Natural Science Foundation of China(Nos.11475206,11175200 and11205170)
文摘A new signal readout method for position-sensitive multi-output detectors,such as those in high-energy spectroscopy measurement and nuclear imaging,was developed by combining the charge division circuit,summing circuit and charge-to-time conversion(QTC) circuit.The 64 outputs of a Hamamatsu H8500 position-sensitive photomultiplier tube were processed,and three digital pulses were generated.The widths of digital pulses were determined using the time-to-digital converter in an field programmable gate array.The energy and position information of incident y-rays is estimated based on the proportionality between the width of digital pulses and input charge created by y-photons.A prototype was built using discrete components and tested,and the energy and position resolutions were improved compared with that obtained with standard ADCs.This method greatly simplifies the front-end electronics and the digital interface.It enables a compact electronics system and an easy integration into an ASIC.
文摘The 64 channel flat-panel position-sensitive photomultiplier tube H8500 (manufactured by Hamamatsu) is widely applied to various small and large array detection equipments. It has 12 stages of metal channel dynodes and a single common anode with the total effective area of 49×49 mm2. Each channel has the area of 5.9×5.9 mm2. In order to reduce the cost of the electronics, a predigested readout technique, DPC circuit for processing the signals from 64 channels was developed for our Micro-PET and PET.
