1. Trickle Background Investigation
SVTRAD sees large dose from LER
Trigger counts often don’t correlate
LER injection backgrounds worse after March 7
Analyze injection sampling triggers to see BaBar readout
Compare date from late Run5 and Run6

2. SVT Integrated Dose per LER Injection
( BEMid, BETop, BEBot )
Run5
Run6

3. SVT Integrated Dose per HER Injection
( BWMid, BWTop, BWBot )
Run5
Run6

4. Integrated Triggers per LER Injection
[# of revolutions which generate background]
( EMC, DCH )
Run5
Run6

5. Integrated Triggers per HER Injection
[# of revolutions which generate background]
( EMC, DCH )
Run5
Run6

6. BaBar Readout
Each injection BaBar samples the detector at a couple different revolutions of the injected bunch.
The particular revolutions which are sampled is scanned over many injections.
We can reconstruct a picture of the average background per injection for each revolution of the injected bunch.
Currently, this scan is done over the first 525 revolutions.

7. LER Injection - SVT Readout
Aug 6, 2006
Apr 1, 2007
short-term bkg
No long term bkg

8. LER Injection - SVT Readout
Aug 6, 2006
Apr 1, 2007

9. LER Injection - EMC Readout
Aug 6, 2006
Apr 1, 2007
Pre-amp saturation effect

10. LER Injection - EMC Readout
Aug 6, 2006
Apr 1, 2007

11. LER Injection - DRC Readout
Aug 6, 2006
Apr 1, 2007
DRC is sensitive to this
long-term bkg. SVTRAD
may see this as well.

12. LER Injection - DRC Readout
Aug 6, 2006
Apr 1, 2007

13. Observations
SVTRAD/trigger LER injection monitoring indicates large dose over a small period.
BaBar readout confirms that the detector is getting more exposure in first ~15 revolutions.
EMC is suffering saturation effects for ~250 usec after LER injection
DRC sees late activity (>100 revolutions) in LER backgrounds as well – may be visible to SVTRAD diodes but not the trigger system.
HER injection is generally worse as well, but not as big a difference from Run5.

14. Extra Slides

15. LER Injection - DCH Readout
Aug 6, 2006
Apr 1, 2007

16. LER Injection - DCH Readout
Aug 6, 2006
Apr 1, 2007

17. HER Injection - SVT Readout
Aug 6, 2006
Apr 1, 2007

18. HER Injection - EMC Readout
Aug 6, 2006
Apr 1, 2007