摘要
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.
A new signal readout method for position-sen-sitive 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 γ-rays is estimated based on the pro-portionality between the width of digital pulses and input charge created by γ-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 inte-gration into an ASIC.
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)
