A Real Time Trigger System for Belle II CDC Detector
Jing-Ge Shiu1*, Belle II CDCTRG team2,3,4
1Department of Physics, National Taiwan University, Taipei, Taiwan
2KEK, Japan
3Korea University, Korea
4NTU/NUU/FJU/NCU, Taiwan
* presenting author:徐靜戈, email:physjg@hep1.phys.ntu.edu.tw
I will introuce the trigger system for the Belle II central drift chamber (CDC). The Belle II experiment at the KEK High Energy Accelerator Research Organization in Japan is a B factory aiming at high precision measurements. A real-time track trigger system for CDC is developed to differentiate the physics events from beam background at high luminosity at 8x1035 cm-2s-1. The CDC detector is composed of 14 thousand channels in 9 super-layers. The trigger system collects and pipelines the hit information through a multi-layer trigger system to perform various track finding algorithms: the 2–dimensional tracking for track counting and the 3-dimensional tracking for a sophisticated z-vertex trigger at 1 cm precision. Gigabit optical serial links are used for the data transmission between layers. A user defined protocol is developed to reduce the total latency below 5 microseconds. The design and current status of this system will be presented.


Keywords: Belle II, trigger , real time, CDC