AC-LGAD Detector R&D for the EIC ePIC Experiment

The Time of Flight (ToF) subsystem is a key device of particle identification at the EIC ePIC experiment, especially in the low transverse momentum region up to a few GeV/c. The flight path for the ToF in the central barrel is less than 70 cm due to the compact design of the whole detector. It hence requires an exceptionally good timing resolution of ~30 ps, as well as a fine segmentation to supplement the tracking and a thin material budget for the detectors behind. The technology choice is AC coupled Low Gain Avalanche Diode (AC-LGAD).

We have engaged in the design and development of the ToF subsystem, with a current focus on assurance of the AC-LGAD sensor performance. A newly established “world premier initiative (WPI)” institute at Hiroshima University will be the hub of the work, collaborating with the US ePIC team and other institutes in Japan including Nara Women’s U., RIKEN, Shinshu U., U. Tokyo, and more. The latest status and plans of the R&D of the AC-LGAD ToF subsystem will be discussed with a focus on the activities in Japan and Asia.