The fast control system for HERA-B

Author

Fuljahn, T. ; Hochweller, G. ; Ressing, D.

Author_Institution

DESY, Hamburg, Germany

Volume

1

fYear

1998

fDate

1998

Firstpage

336

Abstract

The HERA-B experiment is dedicated to measure CP-violation in decays of neutral B-mesons. The B-mesons are produced in a nearly overwhelming background of inelastic proton-nucleon-interactions. To reconstruct a sufficient number of B-decays the experiment has to be operated with multiple interactions at a 10 MHz event rate. A granularity of 540,000 channels is required. The challenge for the DAQ system is deadtimeless readout. This requires unprecedented speed of storing and labeling the data. A 50 kHz first level trigger rate needs a fast distribution of accepted-event identifiers. Ambitious plans for drift time measurements require a high precision time reference for the front end electronics. A fast control system has been developed to fulfil these requirements. The system consists of a VME-accessible mother unit with trigger and command processing logic, a two-stage signal distribution system and one individually configurable daughter module with timing adjustment capabilities in each of more than 200 front end electronics crates

Keywords

client-server systems; computerised control; data acquisition; high energy physics instrumentation computing; HERA-B; accepted-event identifiers; command processing logic; control software; data acquisition system; deadtimeless readout; drift time measurement; fast control system; first level trigger; interfaces; timing adjustment; trigger logic; two-stage signal distribution system; Clocks; Control systems; Detectors; Event detection; Pipelines; Signal processing; Storage rings; Synchronization; Time measurement; Timing;

fLanguage

English

Publisher

ieee

Conference_Titel

Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE

Conference_Location

Toronto, Ont.

ISSN

1082-3654

Print_ISBN

0-7803-5021-9

Type

conf

DOI

10.1109/NSSMIC.1998.775157

Filename

775157