Abstract
The PHOBOS data acquisition system based on a RACEway switching network is described. Occupying a single VME crate, the system utilizes 22 PPC750 CPUs working in parallel to compress data from 135 168 silicon pad detectors and an UltraSPARC VME host for event building and data storage. Lossless Huffman coding is used for compression; this reduces the event size fourfold. The two-host disk array is used to stage data before sending them over Gigabit Ethernet to the Relativistic Heavy Ion Collider (RHIC) central computing facility. All trigger and control logic is formed using universal programmable logic VME modules, which can be programmed in situ, even when the system is running. The event building and run control software is written using the ROOT framework. The slow control and configuration makes use of an Oracle database to store configuration and monitoring parameters. The system has been taking data from the PHOBOS experiment at RHIC since June 2000. The achieved data-taking rate is 280 events/s or 28 MB/s, with additional disk arrays it can potentially reach 80 MB/s.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
