H1 Central Trigger | ||
The
H1 Trigger System
is divided into
four levels.
The first and second level systems (L1 and L2) are phase-locked
to the HERA accelerator clock of 10.4 MHz. The L1 system provides
a trigger decision for each bunch crossing after 2.3 µ sec. without causing
dead time. A subset of the subdetector system data is used by most systems
to generate fast informations concerning the general properties of the event.
This is encoded in Boolean decisions (Trigger Elements). The
L2 system decision is presently derived from a combination of two
independent hardware systems within 20 µs of the preceding L1 Keep signal, allowing
sufficient time for transmission of trigger information and computation of
the L2 trigger response.
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L1 : 2.3 µ sec. | L2: 20 µ sec. | L3: < 800 µ sec. | ca. 100 ms |
Level 1
(synchronous to HERA clock) |
Level 2
(synchronous to HERA clock)
|
Level
3
(not yet implemented) |
Level 4
(asynchronous to HERA clock) |
Rate: 1 kHz
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|
Rate: 50 Hz |
Rate: 5 Hz |
Stops the Pipelines | Starts the Readout | Starts Event building |
Data Logging |
L1 Internal Page |
L2 Internal Page
Neuronal Network Trigger Topological Trigger |
Documentations | L4 Home-page |
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Central Trigger | (Subsystem Triggers) | CT internal page |
DC-R/Phi Trigger | CJC1/CJC2 Drift Chambers | |
z-Vertex Trigger | CIP / COP / FPC Prop Chambers | zVtx internal page |
MWPC-NIM Trigger | CIP Prop Chamber | |
DC-R/Z Trigger | CIZ / COZ Drift chambers | |
Forward Ray Trigger | CIP / FPC Prop chambers | |
Time of Flight Trigger | BToF / FToF / FIT / VLQ -ToF | |
Liquid Argon Trigger | LAr_el/LAR_had main Calo | LAr Trigger internal page Jet Trigger Page |
Forward Muon Trigger | fwd_muon drift chamber | |
SpaCal Trigger | Spcl_el/Spcl_had backw. Calo | SpaCal Trigger internal page |
Digital (central) Muon Trigger | Instrument. Iron (FC/FB/BB/BC) | Digi_mu internal page |
Very low Q^2 Trigger | VLQ Si-Tracker/Calo | VLQ Calo Trigger |
Backward DC Trigger | BDC | |
Luminosity Trigger | etag_8/33/44/108; gamma_tagger | |
Forward Proton/Neutron Trigger | FPS / FNC |