Development of the proton beam monitor based on the thin diamond crystal for the COMET Experiment

Y. Fujii, H. Nishiguchi, S. Mihara, Y. Hashimoto

Research output: Contribution to journalArticleResearchpeer-review


In the COMET experiment, it is essential to establish the online monitor that enables to detect few residual protons between consecutive main proton bunches to search for the muon-to-electron([Formula presented]) conversion with a sensitivity below [Formula presented]. A thin diamond based detector is proposed because of its ideal characteristics. To realise the diamond based residual proton monitor, a noise suppression is essential since the number of electron–hole pairs generated by a single proton is relatively small in a thin diamond ([Formula presented]5000 [Formula presented]/[Formula presented]). The prototype detector based on a 0.5 mm thick diamond was developed to evaluate the proton counting capability. The beam test using a 30 GeV proton beam was performed with this prototype and the result is reported in this paper.

Original languageEnglish
Pages (from-to)669-670
Number of pages2
JournalNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
Publication statusPublished - 2019
Externally publishedYes


  • CLFV
  • Diamond detector
  • State solid detectors

Cite this