A study on ion initiated photomultiplier afterpulses

Nural Akchurin, Heejong Kim

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Ions originating from the ionization of the gas impurities by the electrons inside the photomultiplier tube are generally responsible for the delayed pulses that arrive several hundred nanoseconds after the main pulse. These afterpulses are studied in detail for a Hamamatsu PMT (R7525). Their timing, amplitude, rate and high-voltage dependence are measured and monitored in a helium-rich environment for an extended period. The afterpulse rate due to helium is determined to be 5-10 × 10- 4 per ppm per photoelectron. The characteristic afterpulse features are that their rate linearly depends on the main pulse charge but the afterpulse charge itself is essentially independent of it. We discuss the timing distribution and the origin of these afterpulses.

Original languageEnglish
Pages (from-to)121-126
Number of pages6
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Issue number1
StatePublished - Apr 21 2007


  • Afterpulse
  • Helium ion
  • Photomultiplier tube


Dive into the research topics of 'A study on ion initiated photomultiplier afterpulses'. Together they form a unique fingerprint.

Cite this