Physics

Grid Activities in CDF

The main aim is to integrate the CDF physics analysis software into the Sequential Access via Meta-data (SAM) system currently used extensively by the other experiment at the Tevatron, D0. Also of importance on a limited scale is to develop strategies and code for deploying high-energy physics applications into a highly distributed, GRID-based architecture.

UK institutes are playing a leading role in organising GRID activities for the CDF experiment. The Glasgow University group is providing overall coordination for GRID activities for the CDF experiment, which includes University College London as well as Oxford University.

The CDF particle physics experiment has an object orientated software environment known as AC++. This framework is intended to apply to all event data processing applications including trigger, simulation, reconstruction and user analysis. One key area that needs effort deals with access to the CDF data from a remote institution. Several data sets that have been passed through filters exist both at Fermilab and at other remote institutions, but CDF has yet to establish a protocol, which makes these data easily identifiable and accessible to the general user who is not based at the CDF site.

The other experiment at the Tevatron, D0, has a system of data transport called SAM. This system not only permits the easy transfer of files between SAM stations at different institutions, it also defines a meta-data protocol which allows the local SAM station to find out what type of data exists at other SAM stations. The SAM framework generates its own meta-data on a file before that file is copied to the local SAM station for analysis purposes.

A key element of the project is to aid in the integration of the SAM system into the CDF analysis framework (AC++). Extensive use will be made of six 8-way IBM SMP servers with a total of 9TB of available disk space in order to set up a system of SAM stations and data stores within the UK. Additional SMP servers and disk storage, approximately doubling the current levels, are expected to be purchased late in 2002 to further aid this effort.