Performance of the MCP-PMTs for the TOP counter in the Belle II experiment

5 Jun 2014, 16:30
20m
Berlagezaal (Beurs van Berlage)

Berlagezaal

Beurs van Berlage

Oral Sensors: 1d) Photon Detectors I.d Photon

Speaker

Mr Takuya Yonekura (Nagoya university)

Description

We developed the micro-channel-plate (MCP) PMT for the Time-of-Propagation (TOP) counter, which is a novel Cherenkov counter to be used for particle identification in the Belle II experiment. The developed MCP-PMT has excellent performance for single photon detection; a timing resolution of about 40ps (sigma, including readout jitter), a nominal gain as high as 2 x 10^6, and a position sensitivity of about 5mm with 4 x 4 anode. In the Belle II TOP counter, 512 MCP-PMTs are used under a magnetic field of 1.5T. The performance details were inspected with and without the magnetic field. The gain on each anode was found to vary up to a factor of two over the 16 anodes in some of the MCP-PMTs. We will discuss on this issue. The gain was dropped by 20-80% in a 1.5T magnetic field. The reason is considered that the secondary electrons can be localized and the electron amplification can be saturated. The rate of the gain drop seems to have a correlation with the high-voltage applied to obtain the nominal gain. We will discuss on the gain drop and its rate. The photon detection efficiency was also measured in a 1.5T magnetic field. The results on about 300 MCP-PMTs will be reported. Regarding the lifetime of the MCP-PMT, we succeeded in extending the lifetime significantly by introducing the atomic layer deposition technique on MCP coating. The results of the lifetime measurements will be reported.

Primary author

Mr Takuya Yonekura (Nagoya university)

Co-authors

Mr Daiki Furumura (Nagoya university) Dr Kazuhito Suzuki (Nagoya university) Dr Kenji Inami (Nagoya university) Dr Kodai Matsuoka (Nagoya university) Mr Shigeki Hirose (Nagoya university) Dr Tomokatsu Hayakawa (Nagoya university) Prof. Toru Iijima (Nagoya university) Mr Yuhei Ito (Nagoya university) Dr Yuji Kato (Nagoya university) Dr Yutaro Sato (Nagoya university)

Presentation Materials