Practical experience:

Data Acquisition en T2

NIKHEF participates in the design and construction of the second-level trigger (T2), the data-acquisition system (DAQ) and the detector control system (DCS) of the ATLAS (CERN) detector in Geneva. The tasks of these systems are considerably more demanding than the tasks of these systems in state-of-the-art experiments. For example, the trigger has to reduce the initial proton-proton collision frequency at the Large Hadron Collider (LHC) of 40 MHz (~ 10⁹ events/s) to about 100 Hz (the 100 interesting events/s). The data acquisition system has to deal with 65 million data channels, which produce about 200 GByte of data after a crude first selection of events. The DCS has to control and to survey an unprecedented large and complex high-energy physics experiment. Advanced computer instrumentation is necessary to fulfil in a cost-effective way the requirements. Two key techniques are:

	high performance parallel processing
	object-oriented programming

At present the NIKHEF group contributes to the following specific items of the 2^e level trigger:

	architecture studies. This includes the development of prototypes for a 'demonstrator' system at CERN. NIKHEF is contributing with software and hardware (at present a PCI card with ADSP-21060 DSP is being developed). Modelling with discrete event simulation.
	performance studies. The performance of the 2^e level trigger on the silicon central tracker (SCT) data. This includes pre-processing and track segment finding. Study of signal loss and background rejection for relevant physics processes.

the DAQ:

front-end (the first hardware buffer where the data from the detectors is collected) crate prototyping

the DCS:

	research on supervisory systems
	local control systems for muon chambers and for the SCT

Depending on personal interest the work can be oriented more towards performance of the trigger on one hand or to the application of advanced computer technology (hardware as well as software) in the trigger, DAQ and DCS systems on the other.

Further information can be obtained from:

	Prof. Dr. Ing. B. van Eijk
	Dr. Ir. J.C. Vermeulen (NIKHEF, tel. 020-592 5108, email i73@nikhef.nl)

Latest change: 13 January 1999

nederlandse versie

email: vaneijk@nikhef.nl