The XTRP crate is one of the core component of the L1 trigger system. The XTRP receives track information from the XFT and distribute the tracks and information derived from the tracks to the Level-1 and Level-2 trigger subsystems.

The XTRP system is compose of 12 DataBoards (DB), a Track Trigger board (TT), a Clock Board and two flavor transition modules.

We have 2 track trigger boards. One called 2TT, which can handle up to 6 tracks and the other called 3TT, which can handle up to 10 tracks. The 3TT can also perform transverse mass trigger which is still under commissioning.

The XTRP performs three main tasks (click here for dataflow diagram).

• extrapolation of the tracks to the central muon systems (CMU/X) and sends information to the L1 MUON trigger. Similarly, extrapolation of the tracks to the central calorimeter and sends information to the L1 CAL trigger.
• select tracks (up to 6 for the 2TT & up to 10 for the 3TT) above given p_T threshold & uses p_T & phi information to define L1 TRACK trigger.
• Once a L1 accept is received, the tracks are lached into the L2 buffers and then delivered to the L2 processor and SVT

Since December 2004, the 3 Track Trigger board (3TT) is in the crate.

Considering the above, if something goes wrong with the XTRP crate, better be fix asap if you want to get some track triggers ... Thank God for us, the XTRP is well behave.

If something goes wrong, click first on the Online Monitoring link to try to determine if the problem comes from the XTRP crate. Then, if it does and it's really serious and no one around knows what to do ... well ... don't panic ... and... page us.

XTRP pager: 218-9513 (dial 9, then #, wait for beeps, enter number you wish victim to call back, hang up)

• Anyes's Office # 3899

• Chris's Office # 3934

• Kevin's pager 630 218 4121