학술논문

The STAR experiment's data acquisition system
Document Type
Conference
Source
1999 IEEE Conference on Real-Time Computer Applications in Nuclear Particle and Plasma Physics. 11th IEEE NPSS Real Time Conference. Conference Record (Cat. No.99EX295) NPSS real time conference Real Time Conference, 1999. Santa Fe 1999. 11th IEEE NPSS. :63-66 1999
Subject
Computing and Processing
Data acquisition
Detectors
Ion accelerators
Phase detection
Optical receivers
Optical fibers
Laboratories
Physics
Process design
Workstations
Language
Abstract
STAR is one of the major experiments at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, Upton, USA. RHIC together with STAR began commissioning in June 1999 while the first physics data will be gathered after October 1999. STAR will study ultrarelativistic heavy-ion collisions using its large TPC (Time Projection Chamber) in the first months of running. STAR's data acquisition system is a custom-built massively parallel system hierarchically organized into VME crates interconnected via a fast SCI network. The twelve sector VME crates each contain a Sector Broker CPU and. Twelve custom receiver boards, which are connected to the detector via a fiber optic link. Each receiver board hosts three custom mezzanine boards with a single Intel I960HD CPU used to preprocess the data. The system is designed to process 100 events/s of incoming data keeping the output data rate on the order of 20 MB/s (1 event/s). Events will be selected using a third-level trigger utilizing real-time tracking. Built events are transported via SCSI to a workstation acting as an event buffer and forwarded to the RHIC Computing Facility via Gigabit Ethernet for final archiving.