The following email has been sent to Mr. SAWADA, Ryu:

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Dear Ryu Sawada,

The submission of your abstract has been successfully processed.

Abstract submitted: https://indico.cern.ch/userAbstracts.py?confId=192695.

Status of your abstract: https://indico.cern.ch/abstractDisplay.py?abstractId=47&confId=192695.

See below a detailed summary of your submitted abstract:

Conference: Tipp 2014 - Third International Conference on Technology and Instrumentation in Particle Physics

Submitted by: Mr. SAWADA, Ryu

Submitted on: 28 January 2014 08:27

Title: Upgrade of MEG Liquid Xenon Calorimeter

Abstract content The MEG experiment yielded the most stringent upper limit of the branching ratio of a flavor-violating muon decay $\mu\rightarrow e\gamma$ in 2013. To improve the sensitivity by one order of magnitude, a major upgrade of the detector is planed. The energy and position resolutions of the liquid xenon (LXe) gamma ray detector are limited near the entrance-window by the limited size of the photomultiplier tubes (PMTs). For the upgrade, 2-inch PMTs on the entrance-window are supposed to be replaced by $12\times12$ cm${}^2$ silicon photomultipliers (SiPMs). According to a simulation study, the higher granularity will improve the energy resolution from 2.4% to 1.1% and the position resolution from 5 mm to 2 mm around the entrance-window. To be used in LXe, SiPMs are required to be able to detect vacuum ultra-violet photons (175 nm), be operational in the LXe temperature (165 K) with high enough photo-detection efficiency (PDE) and the gain uniformity. A new type of SiPM is being developed and were tested in LXe. The single-photoelectron detection capability was confirmed, and the PDE for the LXe scintillation light was measured to be 17%. To address an issue of long tail of the pulse due to the large capacitance, a new connection scheme (connecting signal and bias lines in series and in parallel, respectively) was proved to make the pulse shorter. A large prototype of the LXe detector with using $\sim$600 SiPMs will be built in 2014 followed by the construction of the full size detector, where $\sim$4000 SiPMs will be used.

Summary

Primary Authors: Dr. SAWADA, Ryu (ICEPP, the University of Tokyo) sawada@icepp.s.u-tokyo.ac.jp

Co-authors:

Abstract presenters: Dr. SAWADA, Ryu

Track classification: Sensors: 1a) Calorimetry Sensors: 1d) Photon Detectors

Presentation type: --not specified--

Comments: