Author/Authors :
Tomoto، نويسنده , , M and Ohshima، نويسنده , , T and Suzuki، نويسنده , , S and Sugiyama، نويسنده , , A and Yoshida، نويسنده , , K and Matsumoto، نويسنده , , T and Okabe، نويسنده , , T and Ishikawa، نويسنده , , A and Inami، نويسنده , , K and Nagai، نويسنده , , I and Hirose، نويسنده , , M and Fujimoto، نويسنده , , K and Sugi، نويسنده , , A and Akatsu، نويسنده , , M and Sakai، نويسنده , , Y and Uno، نويسنده , , S and Iwasaki، نويسنده , , Y and Suzuki، نويسنده , , J and ، نويسنده ,
Abstract :
We describe the design and performance of a fast Z-trigger system with the BELLE Central Drift Chamber. It utilizes z-position information from the axial/stereo wire hits as well as the cathode strip. This system is essential to reduce the false trigger rate from caused by the spent electrons or positrons interacting with the material around the beam pipe. We tested the performance of the system using cosmic rays in a magnetic field of 1.5 T, provided by a superconducting solenoid. The trigger efficiency was 98% for a single track passing through the interaction region. This trigger was effective in rejecting tracks originating from points more than 10 cm away from the interaction point.
