1. Update on Laser ‘Aftershock’ Triggers
AKA Crazy Laser
12/03/2009
Laser Trigger Update

2. Quick Reminder Triggers in Orbit after 1 Hz Laser calibration event
1 kHz of 1J5
12/03/2009
Laser Trigger Update

3. Monica’s Analysis See other slides attached to agenda
Tile
Triggers
L1Calo
Triggers
See other slides attached to agenda
‘The tentative conclusion here is that there is a shift in the pedestal for L1Calo towers after large laser pulses’
Note also BCID peak at 200
12/03/2009
Laser Trigger Update

4. Pedestal Drift? YES Average FADC 0 count as function of Bcnum
maximum − pedestal
Typical Channel
Worst Channel
PP6, PPM3, MCM9, Chan 0
12/03/2009
Laser Trigger Update

5. (Mostly Monica’s) Conclusions
It is clear we have an analog saturation problem with a long decay
Where? (Tile’s adders, receiver, PPM)
Tile trigger firing suggests Tile (or TCPP?)
Next Steps
With the scope in USA15 patch panels, check the baseline after large laser and CIS events
Repeat this at the different points
Bottom line question: Is this specific to the laser or general for large pulses which are saturating the electronics?
12/03/2009
Laser Trigger Update