Go to the Final-FED
9U VME ProjectWelcome to the CMS Tracker Front-End Driver public pages. If you have any comments or suggestions on their contents please contact John Coughlan These pages were last updated on 24 February 2005.
Go to the Final-FED
9U VME Project
(FED ser 001 prior to fitting of OptoRx modules)
Go to the FED-PMC
Project 
The CMS experiment is due to begin operating at the Large Hadron Collider facility (LHC) at CERN in Geneva Switzerland in 2006. A key component of the CMS detector is the silicon microstrip tracker which is designed to provide robust particle tracking and vertex reconstruction within a strong magnetic field in the high luminosity environment of the LHC.
The microstrip tracker readout system consists of 10 million detector channels and, at expected track occupancies, will generate up to 70% of the final data volume at CMS. The tracker readout system is clocked at the LHC bunch crossing rate of 40.08 MHz and is designed to operate at Level 1 trigger rates of up to 100 kHz. Microstrip signals are amplified and stored in analogue pipeline memory chips (APV) located on the detector. After some elementary signal processing and multiplexing the signals are transferred (over approx 60m) to the experimental counting room via analogue optical links.
In the counting room the analogue optical data are converted back to electrical signals and digitized on Front End Driver (FED) cards. Each ADC channel processes data serially from a total of 256 microstrips (constituting an APV frame). The FEDs provide digital signal processing, including cluster finding to drastically reduce the data rate, before storing the data in local memory buffers until required by the higher levels of the CMS data acquisition system.
The FED is being provided for CMS by the Instrumentation Department of the CLRC Rutherford Appleton Laboratory in the UK in collaboration with Imperial College, London.
A FED prototype has been implemented as an 8 ADC channel PCI Mezzanine Card (PMC). The design of the FED-PMC has been optimized for use in laboratory set-ups and for test beam work. This prototype has electrical inputs and reads out raw data. More than 70 FED-PMC's are now in use by the tracker community. A further production of 40 PMCs is now in progress. First deliveries at CERN are expected by June 2003.
The Final FED which will be installed at CMS will be a 9U format VME card comprising 96 ADC channels with optical inputs. There will be about 450 FED's in the final system. The first 5 boards FEDv1 are now being tested at RAL and Imperial College.
The Tracker Electronics Meetings page (maintained by Geoff) provides a fuller description of the microstrip tracker electronics system and includes minutes and presentations from the regular tracker electronics "systems" meetings.
The Tracker Controls pages (maintained by Sandro) provides additional tracker systems information.
The Tracker DAQ Installation Guide (XDAQ version) provided by Laurent Mirabito.
The APV25 Front-End Pipeline chip was designed by the RAL Instrumentation Microelectronics group.
The TRIDAS project is responsible for co-ordinating the Trigger and Data Acquisition systems (including XDAQ) of CMS.
The pages describing the Tracker Test Beam activities at CERN in 1999 and 2000.
