Development of a non-delay line constant fraction discriminator based on the Pade approximant for time-of-flight positron emission tomography scanner

S. Y. Kim, G. B. Ko, S. I. Kwon, J. S. Lee

Research output: Contribution to journalArticle

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In positron emission tomography, the constant fraction discriminator (CFD) circuit is used to acquire accurate arrival times for the annihilation photons with minimum sensitivity to time walk. As the number of readout channels increases, it becomes difficult to use conventional CFDs because of the large amount of space required for the delay line part of the circuit. To make the CFD compact, flexible, and easily controllable, a non-delay-line CFD based on the Pade approximant is proposed. The non-delay-line CFD developed in this study is shown to have timing performance that is similar to that of a conventional delay-line-based CFD in terms of the coincidence resolving time of a fast photomultiplier tube detector. This CFD can easily be applied to various positron emission tomography system designs that contain high-density detectors with multi-channel structures.

Original languageEnglish
Article numberP01005
JournalJournal of Instrumentation
Issue number1
StatePublished - 16 Jan 2015


  • Analogue electronic circuits
  • Coronary ct angiography (CTA)
  • Front-end electronics for detector readout
  • Gamma camera

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