Distribution of the Timing, Trigger and Control Signals in the Endcap Cathode Strip Chamber System at CMS

This paper presents the implementation of the Timing, Trigger and Control (TTC) signal distribution tree in the Cathode Strip Chamber (CSC) sub-detector of the CMS Experiment at CERN. The key electronic component, the Clock and Control Board (CCB) is described in detail, as well as the transmission of TTC signals from the top of the system down to the front-end boards

Radiation Testing of Electronics for the CMS Endcap Muon System

The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the inner-most portion of the CMS detector, with 8900 rad over ten years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment

Commissioning of the CSC Level 1 Trigger Optical Links at CMS

The Endcap Muon (EMU) Cathode Strip Chamber (CSC) detector at the CMS experiment at CERN has been fully installed and operational since summer of 2008. The system of 180 optical links connects the middle and upper levels of the CSC Level 1 Trigger chain. Design and commissioning of all optical links present several challenges, including reliable clock distribution, link synchronization and alignment, status monitoring and system testing. We gained an extensive experience conducting various tests, participating in local and global cosmic runs and in initial stage of the LHC operation. In this paper we present our hardware, firmware and software solutions and first results of the optical link commissioning

Design Considerations for an Upgraded Track-Finding Processor in the Level-1 Endcap Muon Trigger of CMS for SLHC operations

The conceptual design for a Level-1 muon track-finder trigger for the CMS endcap muon system is proposed that can accommodate the increased particle occupancy and system constraints of the proposed SLHC accelerator upgrade and the CMS detector upgrades. A brief review of the architecture of the current track-finder for LHC trigger operation is given, with potential bottlenecks indicated for SLHC operation. The upgraded track-finding processors described here would receive as many as two track segments detected from every cathode strip chamber comprising the endcap muon system, up to a total of 18 per 60° azimuthal sector. This would dramatically improve the efficiency of the track reconstruction in a high occupancy environment over the current design. However, such an improvement would require significantly higher bandwidth and logic resources. We propose to use the fastest available serial links, running asynchronously to the machine clock to use their full bandwidth. The work of creating a firmware model for the upgraded Sector Processor is in progress; details of its implementation will be discussed. Another enhancement critical for the overall Level-1 trigger capability for physics studies in phase 2 of the SLHC is to include the inner silicon tracking systems into the design of the Level-1 trigger