The interesting data from the VHMPID detector in ALICE could be enhanced with a factor forty using a dedicated trigger device. The proposed High PT Trigger Detector (HPTD) would cover the same acceprance as the VHMPID, and could provide L0 and L1 level triggers to the experiment.

It consists of several tracking layers before- and after the Cherenkov module. In the ALICE magnetic field the trajectories will curve, thus from the locally measured inclination at HPTD the particle's momentum can be estimated.

The trigger logics and readout shall be very quick, thus the tracking layers are providins simple binary information (was there a track or not). To achieve good two-track-separation and low occupancy one needs small clusters. We have developed a modified multiwire detector for the requirements of the HTTD: the Close Cathode Chambers (CCC). Besides the small cluster size; CCCs have low material budged, high mechanical tolerance, and nonetheless simple and cost-effective construction procedure.

The bit-pattern of the detected tracklets are compared to the simulated patter-set via and FPGA, which then can send the proper triggers. Besides the trigger information, the trakcing data can be used to enhance the global tracking, and ensure identification of the mid-momentum protons.

Author: Gergő Hamar