Feb 18 – 22, 2019
Vienna University of Technology
Europe/Vienna timezone

Full System of Positron Timing Counter Having Time Resolution under 40 psec with Fast Plastic Scintillator Readout by SiPMs

Feb 18, 2019, 5:30 PM


Talk Plenary 2


Dr Miki Nishimura (KEK)


A positron timing counter (TC) required 30-40 ps time resolution for ~50 MeV/c positron by the MEG II experiment has been developed. We employed the high segmented design with 512 scintillator plates ($120 \times 40 \times 5$ mm$^3$ and $120 \times 50 \times 5$ mm$^3$) attached 6-SiPM-array at the both ends. Pile up is reduced by the segmented design, and multi-counter measurement improves the overall timing resolution.
All the single counters were assembled and their resolutions were under 100 psec in pre-test with Sr source. The construction and installation was also completed in 2017. An engineering run was performed in the end of 2017 at the $\pi$E5 muon beam line in PSI, which supplies most intense muon beam ($7 \times 10^7$ stops/s on a target) in the world. We successfully operated the full system of TC in the MEG II environment and achieved the time resolution under 40 ps with more than 8 counter hits.
The overall resolution for the signal positrons is estimated to be 38.5 ps by weighting with the number of hits distribution of the signal positrons obtained by MC. The time resolution of TC is improved by a factor of 2 from the MEG experiment.

Primary author


Felix Anton Berg (PSI - Paul Scherrer Institut) Michele Biasotti (INFN Sezione di Genova, dDipartimento di Fisica, Universit`a degli Studi di Genova) Gianluigi Boca (Universita' di Pavia and INFN) paolo walter cattaneo (INFN) Matteo De Gerone (INFN - National Institute for Nuclear Physics) Marco Francesconi Luca Galli (INFN) Flavio Gatti (University and INFN of Genova) Ueli Hartman (Paul Scherrer Institut PSI) Zachary Hodge (Universität Bern) Peter-Raymond Kettle (Paul Scherrer Institut PSI) Mitsutaka Nakao (University of Tokyo (JP)) donato nicolo (pisa university) Wataru Ootani (ICEPP, University of Tokyo) Angela Papa Stefan Ritt (Paul Scherrer Institut (CH)) Massimo Rossella (Universita e INFN, Pavia (IT)) Elmar Schmid (Paul Scherrer Institut PSI) Dr Yusuke Uchiyama (The University of Tokyo) Masashi Usami (ICEPP, The University of Tokyo)

Presentation materials