Summary 500 words
The present CMS Trigger Drift Tube Track Finder (DTTF) fulfills all requirements that were defined in the CMS Trigger Technical Design Report in 2000. One of the design goals was to comply with the latency requirements set by the CMS trigger chain. This, together with the semiconductor technology available at that time required to construct a fully parallel high speed data distribution network. In the usage this network is the least reliable component of the DTTF system. Its maintenance is time consuming and error prone. The other weak point is the control system. Built in seven VME crates the control and monitoring access is slow and complicated. In addition, the present system is exactly suited for the physics requirements of the present CMS Trigger system, there is no possibility to increase its capabilities to accept more or different trigger objects in case of a future detector upgrade.
A new design would allow us to exploit the results of the recent and future developments in electronics. A more compact design using highly reliable internal serial lines for data distribution and traffic could be constructed for a fraction of the original cost. The design framework foreseen is using the uTCA chassis which contains by design those fast serial links necessary for DTTF internal data distribution. The new design similarly to the present one would use Field Programmable Gate Arrays (FPGAs) to implement all required logic functions and processes. The new types of FPGAs also contain all necessary circuitry to include fast serial links. The recent FPGA development made it possible to merge the necessary electronic components for as many as three DT Muon Detector Sector processors into one single chip. As a result the new DTTF System could be composed of two uTCA chassis containing 12 Track Finder boards each. New DTTF boards should be developed that perform this task. The Fast Pipe serial links available in all uTCA systems can serve as a mean of input data distribution and trigger data merging.
The DTTF upgrade activity will be fully synchronized with other upgrade plans of the CMS electronics. We want to use common design units, compatible developments of common services and based on CERN electronics research results. The control of the uTCA system will apply a control software platform to be developed as a joint effort with other groups of the CMS trigger community.
The shutdown planned for 2016-2017 is a perfect time as deadline for the CMS Trigger Drift Tube Track Finder unit upgrade activity. The development plan foresees to perform feasibility studies in order to find the best technology and arrangement. This will be followed by the construction of a technology evaluation prototype that allows us to judge the capacities and limits of the future system. After this a pre-production prototype will be built which performs all functions of the final electronics. The software development will be made in parallel with the hardware activity.