The muon trigger group is (as the name implies) concerned with the construction, maintenance and running of the trigger system of the COMAPSS experiment, mainly for the muon program.
The purpose of this page is to give an access point to the available documentation of the trigger system, in the section "Downloads of trigger related documentation" you can find the public documentaion, the most interesting part there is "The trigger paper" as published in NIM A.
The section "Details of the trigger system" contains some more detailed documents and internals, acces thereto is therefore restricted to collaboration members.
The trigger system of the COMPASS experiment at the CERN polarized muon beam is presented. It detects muon scattering events on (polarized) nucleons with a relative energy loss exceeding a selectable value ymin independent of the four-momentum transfer. The requirement of a minimum energy deposit in a hadron calorimeter rejects background events like scattering on electrons, elastic and quasi-elastic radiative events as well as events from beam halo tracks. The trigger system which can be considered as a tagger for quasi-real photon events is now, along with larger trigger hodoscope system for deep inelastic scattering events, in regular use for the measurement of the gluon polarisation [Delta]G/G.
C. Bernet, A. Bravar, J. Hannappel, D.v. Harrach, R. Hermann, E. Kabuß, F. Klein, A. Korzenev, M. Leberig, M. Ostrick et al.,
The COMPASS trigger system for muon scattering,
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 550, Issues 1-2, , 11 September 2005, Pages 217-240.
This page was updated on May 6th, 2006
by Local Webmaster