Shift summary
1. Restored the 1GeV setup from yesterday
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Reached 400 bunches and ~1nC - very stable, flat charge profile, but not zero losses
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Toroids recalibrated at 1.2nC
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Transmission changes through the gun collimator
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Cannot take gun collimator out - AC39 losses increase
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Several quads adjusted, solenoid adjusted, but not yet tried re-matching
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Vector Sum for ACC45:
2. Increased charge. Reached ~1.4nC 400 bunches at which point started to get TPS integrated loss alarms (trip threshold is current 50nC over entire bunch train).
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Went to 1.6nC at 300 bunches, collimator blms limited
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Losses are in the collimator
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Did not yet look at matching with the higher charge
3. Started re-commissioning the piezos and new piezo server for ACC67
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Piezos are working, AC control is working
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There is still a problem with the DC control - no effect on the cavities. Testing is in progress
Tomorrow's afternoon shift: next machine tuning shift. Will run a matching at the higher charge.
Piezos: switched on, seem to not detuning anything
-- server not working for DC voltage (security prevents it - Konrad (can change AC
-- Increased flat-top length of ACC23 of 50us
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-- Gun is at 440us
-- Beam loading compensation is adjusted to all stations - will need to look again when we increase the beam loading
Laser: in rf-only mode, we can continue to run the laser into the laser shutter (maybe up to 400 bunches). This would help with the laser thermal stability.
Per Siggi: can improve the thermal stability by adjusting BBO.
Reference save-set from this morning's shift with 1.2nC and 400 bunches - use the save set from 13:14
Losses at 10DBC2 or at BC3 - cause losses downstream.
Orbit feedback system was briefly tested (successfully) in horizontal plane to stabilize the orbit in the undulator section.
