Readout electronics for the central drift chamber of the Belle II detector

The Belle II detector is designed for a high luminosity upgrade of the Belle detector and the KEKB accelerator at High Energy Accelerator Research Organization (KEK), Japan, to study flavor physics. A design luminosity is about 40 times higher than the KEKB, 8×10³⁵ cm^-2s^-1. The number of readout channels of the drift chamber is 14392 chs. In order to reduce the number of cables between the readout electronics and an electronics hut, the readout electronics is designed to locate at near an endplate of the chamber. The electronics consists of 300 modules having four interface cables: system interfaces, a trigger system interface, and a data acquisition system interface. We tested the electronics with a test detector and have confirmed that the test results meet the requirements from the Belle II experiment.