View - HEPHY

Figure 4.3: Overview of the DT local trigger [22].reduction by requiring coincident tracks.Cathode Strip Chamber Local TriggerThe cathode strip chambers also detect separate track candidates in the two coordinatesη and φ. While both views produce Locally Charged Track (LCT) segments, theanode readout electronics are optimized to provide precise bunch crossing informationby measuring the coincidence of hits on multiple layers, while the cathode readout isoptimized to provide a precise measurement of the φ coordinate.In the φ view, hit information is generated from cathode strip signals digitized athalf-strip precision. To suppress the considerable background in the endcap regions,the hit distribution is then converted to track candidates by requiring coincidencebetween multiple layers compatible with predetermined muon hit patterns. If a matchis found, a cathode local charged track (CLCT) is generated and sent to the triggermotherboard (TMB).For the θ coordinate, signals from wire groups consisting of about 10 anode wiresform the primary hit information. A pattern comparison similar to that for CLTCs isperformed and the resulting anode locally charged tracks are sent to the TMB. TheTMB then correlates θ and φ information and forwards the resulting LCT informationto a muon port card (MPC), which receives LCT information from nine TMBs and40