Speaker
Mr
Shinji Ogawa
(The University of Tokyo)
Description
The MEG II experiment is an upgrade of the MEG experiment to search for the
charged lepton flavor violating decay of muon, $\mu^+ \rightarrow e^+ \gamma
$. The performance of the liquid xenon (LXe) γ-ray detector will be greatly
improved with a highly granular scintillation readout realized by replacing
216 photomultiplier tubes (PMTs) on the γ-ray entrance face with 4092 Mult
i-Pixel Photon Counters (MPPCs). For this purpose, we have developed a new t
ype of large area MPPC which is sensitive to the LXe scintillation light in
vacuum ultraviolet (VUV) range, in collaboration with Hamamatsu Photonics K.
K. This MPPC is a discrete array of four $6 \times 6 \, \mathrm{mm^2}$ chip,
and a sufficiently short time constant for a single photoelectron waveform
is achieved by connecting them in series. An excellent performance of MPP
C has been confirmed in our test including high photon detection efficiency
(> 15%) for LXe scintillation light. In this presentation, the performance o
f our VUV-sensitive MPPC obtained from these tests will be reported.
Author
Mr
Shinji Ogawa
(The University of Tokyo)
