1. TDC Occupancy Estimate
Use “merged data” that was created for XFT studies.
Described in CDF 7039
Use bunch-by-bunch L measurements
Samples produced by adding “per event” luminosities
estimate COT conditions up to L~4.5E32 cm–2s–1
More accurate than simply saying 9 int/cross=4E32cm–2s–1
Limitation is in the accuracy of the hit merging
Min bias/zero bias data from May 2003, aging not a much of a factor.
Samples:
“Min bias” = 1 min bias trigger + N zero bias
“Electron data” = EM8 trigger + N zero bias

2. Occupancy at high L
Min bias data, hits/wire for 4<L<4.5E32cm–2s–1
#hits

3. Occupancy versus L Min bias: mean # of hits per wire per SL versus L
Average # of hits/wire
SL1
SL2
See saturation effect in inner SL.
L(1029)
SL3
SL4

4. Occupancy versus L Min bias: mean # of hits per wire per SL versus L
Average # of hits/wire
SL5
SL6
Don’t see saturation effect in outer SLs.
L(1029)
SL7
SL8

5. Occupancy versus L Electron: mean # of hits per wire per SL versus L
Average # of hits/wire
SL1
SL2
See saturation effect in inner SL.
L(1029)
SL3
SL4

6. Occupancy versus L Electron: mean # of hits per wire per SL versus L
Average # of hits/wire
SL5
SL6
Don’t see saturation effect in outer SLs.
L(1029)
SL7
SL8

7. Comments on Occupancy
Inner SL saturation turns-on around 2.5E32cm–2s–1
Outer SL don’t show saturation.
Fraction of events with more than 4 hits is tiny
Truncation at 4 hits/wire not a problem.
Electron data shows higher occupancy than min bias data at low luminosity, but the two become indistinguishable at higher luminosity.

8. Looking at “Most Occupied”
Event-by-event processing may be limited by slowest (most occupied) TDC.
For each event, count total number of hits in each 96 channel TDC. Plot average occupancy for the “most occupied” TDC.
Following plots show average number of hits/wire for the most occupied TDC in each event.
For total TDC occupancy, multiply the numbers by 96.

9. Most Occupied versus L
Min bias: mean # of hits per wire per SL versus L
Average # of hits/wire for most occupied TDC.
SL1
SL2
See saturation effect in inner SL.
L(1029)
SL3
SL4

10. Most Occupied versus L
Electron: mean # of hits per wire per SL versus L
Average # of hits/wire for most occupied TDC.
SL1
SL2
See saturation effect in inner SL.
L(1029)
SL3
SL4

11. Summary For 4<L<4.5E32cm–2s–1 Min bias Electron data Hits/wire
Hits/wire most occupied
SL1
2.2
3.0
SL2
2.0
2.6
2.1
SL3
1.8
2.5
SL4
1.4
1.5
SL5
1.2
1.3
SL6
1.0
SL7
0.8
1.6
SL8
0.6
0.7