Difference between revisions of "Level-1 Trigger"

Revision as of 17:06, 14 September 2014

The main goal of the GlueX experiment is the search of exotic mesons produced in interactions of 8.4 - 9.0 GeV linearly polarized beam photons with a liquid hydrogen target. The beam photons are created by the 12 GeV electrons incident on a diamond crystal via bremsstrahlung process. The GlueX detector will start taking data at a luminosity corresponding to about 10⁷ photons per second in the photon-beam energy range of 8.4 < E_γ < 9.0 GeV. The Level-1 trigger has to reduce the rate from electromagnetic and hadronic interactions seen by the GlueX detector to a level acceptable by a data acquisition for writing events directly to tape, about 20 kHz. Later, the luminosity will be increased by an order of magnitude to 10⁸ photons per second. For high-luminosity runs, events accepted by the Level-1 trigger will be sent to the thirt level trigger at the rate which should not exceed 200 kHz. The Level-3 trigger will perform an event reconstruction on a PC farm allowing to further reduce low-energy photon interactions and providing an additional rate reduction of about factor of 10. At the same time, the Level-1 trigger has to accept all multi-particle exotic meson candidates produced in the beam energy range E > 8 GeV.