Evaluation of novel KEK/HPK n-in-p pixel sensors for ATLAS upgrade with testbeam

R. Nagai, J. Idárraga, C. Gallrapp, Y. Unno, A. Lounis, O. Jinnouchi, Y. Takubo, K. Hanagaki, K. Hara, Y. Ikegami, N. Kimura, K. Nagai, I. Nakano, R. Takashima, S. Terada, J. Tojo, K. Yorita, S. Altenheiner, M. Backhaus, M. BombenD. Forshaw, M. George, J. Janssen, J. Jentzsch, T. Lapsien, A. La Rosa, A. MacChiolo, G. Marchiori, C. Nellist, I. Rubinsky, A. Rummler, G. Troska, P. Weigell, J. Weingarten

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


A new type of n-in-p planar pixel sensors have been developed at KEK/HPK in order to cope with the maximum particle fluence of 1-3×1016 1 MeV equivalent neutrons per square centimeter (neq/cm2) in the upcoming LHC upgrades. Four n-in-p devices were connected by bump-bonding to the new ATLAS Pixel front-end chip (FE-I4A) and characterized before and after the irradiation to 2×1015 neq/cm2. These planar sensors are 150μm thick, using biasing structures made out of polysilicon or punch-through dot and isolation structures of common or individual p-stop. Results of measurements with radioactive 90Sr source and with a 120 GeV/c momentum pion beam at the CERN Super Proton Synchrotron (SPS) are presented. The common p-stop isolation structure shows a better performance than the individual p-stop design, after the irradiation. The flat distribution of the collected charge in the depth direction after the irradiation implies that the effect of charge trapping is small, at the fluence, with the bias voltage well above the full depletion voltage.

Original languageEnglish
Pages (from-to)78-83
Number of pages6
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Publication statusPublished - Jan 21 2013

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Instrumentation


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