Performance of the H1 fast track trigger - operation and commissioning results

The H1 experiment at the electron-proton collider HERA has built a new fast track trigger to increase the selectivity for exclusive final states, especially those with heavy quarks, and to cope with the higher background rates after the HERA luminosity upgrade. Hits measured in the central jet chamber of H1 are combined to track segments by performing 5 middot 10
¹²
mask comparisons per second using content addressable memories (CAMs). These segments are collected and transmitted via 5 Gbit/s LVDS links to custom made multipurpose processing boards, where they get linked and reconstructed to three dimensional tracks within 20 mus. On the third level resonances are identified in 100 mus by a farm of PowerPC boards. Since 2005 the FTT level one has replaced the existing drift chamber trigger and is the major track trigger of the H1 experiment. In order to further increase the selectivity the second level has started to operate. First analyses of the data show that also the second level fulfills the design specifications