Links:
General Description:
The CSC Track-Finder is defined to be the collection of electronic boards which are on the receiving end of the optical links sent by the CSC local trigger and which transmit L1 muons to the Global Muon Trigger (GMT). The CSC Track-Finder is implemented as 12 Sector Processors (SP) that identify up to the three best muons in six 60° azimuthal sectors of each endcap. Information is not shared across sector boundaries. Each Processor is a 9U VME card housed in a crate in the counting room of CMS. Three Sector Receiver (SR) cards also in the crate collect the optical signals sent from the Muon Port Cards of one sector and transmit data to a Sector Processor via a custom point-to-point backplane. A maximum of six track segments are sent from the first muon station in one sector, and three each from the remaining three stations.
Each Sector Receiver (SR) receives via optical links the Local Charged
Track (LCT) information for 3 muons from each of two Muon Port Cards (MPCs)
located at the periphery of the CMS detector. This information is then
synchronized and reformatted within the SR (via look-up tables) into angular
variables for the muons: the azimuthal angle (phi), the local slope angle
in phi (phi_b), and the rapidity (eta). These data, along with bits summarizing
muon quality and other diagnostic information are then communicated to
the Sector Processor (SP) and the (barrel muon) DT Track finder in the
(differing) format expected by each. Complete input information is also
stored for readout by the DAQ system for accepted events. In addition,
a VME-readable counter and log of detected hardware errors is included.
The basic elements of the SR are shown below.
Details of the look-up tables for each muon candidate are shown below:
