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Plans for usage of first beams with RPC triggetr. HR test of RPC readout in CRAFT Summary of Synchronization in CRAFT Known issues and News. Tasks with first beams. Beam shots on collimators: not useful for calibration, can be used to check how many data we can transmit .
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Plans for usage of first beams with RPC triggetr • HR test of RPC readout in CRAFT • Summary of Synchronization in CRAFT • Known issues and News
Tasks with first beams • Beam shots on collimators: not useful for calibration, can be used to check how many data we can transmit. • Halo muons: - very little with RPC. • First beam collisions (450GeV, 3.5TeV) – useful for synchronisation studies. Especially in case of collisions in only a few known, fixed BXes. RPC synchronisation does not relay on DT or CSC. Needed: RPC readout only (+GMT).
Synchronisation with LHC beams We consider two options: • Start-up with cosmic synchronisation. • Modify current cosmic synchronisation with correction from muon delay (correction from geometry). To correct initial synchronisation parameters (for both cases) we make histograms for each LinkBoard. LB is a base unit keeping synchronisation parameters. The histogram can be made only from readout data (we have -3,+3BX which is enough). Than shift wrt expected trigger BX is computed and updated parameters are loaded to DB. Procedure exists and is well tested (used for cosmic case). In order to provide a trigger we can extend a hit signal to a few consecutive BX. Then hits can be attached to known BX of LHC pp collision (or to that given by barrel, TC9, where cosmic and LHC timing is similar). We do not need a trigger in THE pp BX. That with cosmic synchronisation parameters should be fine. We can compute histogram average from <10 events, 1500 LBs, 5 hits/mu. Assuming flat distribution in eta (which is not a case due to different penetration length) we need <1e4 muons which know the BX to which data should be associated .