ATLAS Tile Calorimeter Read Out  

(CERN, Stockholm University, Universitat de València, University of Chicago)



It is planned to transmit data from the ATLAS Tile Calorimeter front-end electronics to the Readout Driver (ROD) modules by optical S-LINK. The front-end electronics is housed in 256 3-m-long drawers located on the detector. A partially retracted drawer from the Module 0 version of the detector is shown in the photo. Although the S-LINK source card (LSC) is not visible in the photo, it will be a mezzanine card similar to the ones shown mounted on the drawer mother board. In this location the expected radiation dose is about 20 Gy (2 KRad) over the lifetime of the experiment. In addition, the S-LINK will be used to send data from the RODs to the Readout Buffer (ROB) modules.

Chicago and Stockholm are preparing the front-end electronics and Valencia the RODs.

The first demonstration of the system using Fibre Channel S-LINK took place in the CERN H8 test beam in July 1998. A group of 30 channels was equipped with digitizers located inside the electronics drawers and the data was transferred out over the S-LINK duplex fiber to an S-LINK to PMC interface card mounted on a CES 8062 VME-processor module. The DAQ system used software from the Prototype-1 DAQ project for transferring data from S-LINK into the VME-based DAQ system.

Data were recorded with electrons and pions at several energies between 50 and 150 GeV. The system was extremely quiet in terms of electrical noise. The analog signals showed a noise equivalent to 17 MeV in the calorimeter, or 1.1 ADC counts. This was in excellent agreement with a SPICE simulation of the front-end electronics. The planned dynamic range and linearity were achieved and the readout performance exceeded design specifications.

In 1999 further test beam studies were performed with Version 2 of the digitizer cards containing, for the first time, the TileDMU ASIC. The system was coupled to the outside world using the same Fibre Channel S-LINK system as in 1998.

Radiation tests were performed on a simplex S-LINK over GLINK system and the results indicated a factor of safety of over 50 for a 10 year operating life in the planned location in the Tile Calorimeter.

In 2000 it is planned to test calorimeter modules using a simplex S-LINK over GLINK system with the LSC fully integrated into an on-detector interface card. The LDC cards will be hosted by CES 8062 VME-processor modules which will perform the ROD functions.

The success of all these tests was greatly facilitated by the easy availability of the S-LINK components and the well defined protocol for their use. Erik van der Bij from the CERN S-LINK group provided outstanding support in the form of consulting, loan of components, and a design review of the electronics interfacing to the S-LINK. His help is greatfully acknowledged.

The next phase of the work is to evaluate the radiation tolerance of the system to the level described above and to strengthen any weaknesses. In the next version of the readout design, the S-LINK LSC components will be mounted directly on the front-end interface board.



CERN - High Speed Interconnect - S-LINK
Page maintained by Jim Pilcher. Last updated 5-July-00.