TDC Occupancy Estimate

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 L4.5E32 cm2s1
• More accurate than simply saying 9
  int/cross4E32cm2s1
• 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 4ltLlt4.5E32cm2s1

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)
SL4
SL3
4
Occupancy versus L

• Min bias mean of hits per wire per SL versus L

Average of hits/wire
SL5
SL6

• Dont see saturation effect in outer SLs.

L(1029)
SL8
SL7
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)
SL4
SL3
6
Occupancy versus L

• Electron mean of hits per wire per SL versus L

Average of hits/wire
SL5
SL6

• Dont see saturation effect in outer SLs.

L(1029)
SL8
SL7
7
Comments on Occupancy

• Inner SL saturation turns-on around 2.5E32cm2s1
• Outer SL dont 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)
SL4
SL3
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)
SL4
SL3
11
Summary

• For 4ltLlt4.5E32cm2s1

Min bias Min bias Electron data Electron data
Hits/wire Hits/wire most occupied Hits/wire Hits/wire most occupied
SL1 2.2 3.0 2.2 3.0
SL2 2.0 2.6 2.1 2.6
SL3 1.8 2.5 1.8 2.5
SL4 1.4 2.1 1.5 2.1
SL5 1.2 2.0 1.3 2.0
SL6 1.0 1.8 1.0 1.8
SL7 0.8 1.6 0.8 1.6
SL8 0.6 1.3 0.7 1.3