Study of avalanche photodiodes for soft X-ray detection below 20 keV

Y. Yatsu*, Y. Kuramoto, J. Kataoka, J. Kotoku, T. Saito, T. Ikagawa, R. Sato, N. Kawai, S. Kishimoto, K. Mori, T. Kamae, Y. Ishikawa, N. Kawabata

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


The performance of the large area reach-through avalanche photodiode (APD), manufactured by Hamamatsu Photonics, K.K. as a high resolution X-ray detector is presented. The mentioned APD has an area of 3 mm ∅, a fast time response for signal carrier collection and its thick depletion layer of 130 μ m shows a potential to be used as an effective X-ray absorber below 20 keV. Having a capacitance of ∼ 10 pF and a low dark current of 5 nA for a gain of 15, at room temperature, this APD had demonstrated one of the best energy resolutions within this kind of devices: 6.4% (FWHM) for 5.9 keV photons with a minimum detectable energy of 0.3 keV, measured at - 20 {ring operator} C. The experiments for the timing property were made in a synchrotron beam facility using an 8 keV X-ray beam; the reached count rate was above 108 counts/s, corresponding to a very short dead time of 4.5 ns/pulse. In order to test the radiation hardness of the APD, the device was irradiated at a Ring Cyclotron Facility with a 53.5 MeV proton beam. The total dose was of 11.3 krad and no fatal damage was found in the APD, although the dark current of the APD had shown an increase of one order of magnitude. Finally, the obtained results allow us to affirm that the reach-through APD has the potential to become an excellent X-ray detector, especially in the space mission application.

Original languageEnglish
Pages (from-to)134-143
Number of pages10
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Issue number1
Publication statusPublished - 2006 Aug 1
Externally publishedYes


  • Avalanche photodiode
  • X-ray detector

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation


Dive into the research topics of 'Study of avalanche photodiodes for soft X-ray detection below 20 keV'. Together they form a unique fingerprint.

Cite this