Yale Offline Software update Outline

1. Yale Offline Software updateOutline • Algorithm • Task distribution? • Work on implementing algorithm

2. Algorithm C E E E E E E C E I I I I I I E E I I I I I I E E I I I I I I E E I I I I I I E E I I I I I I E E I I I I I I E C E E E E E E C • Geometry • I = interior tower • E = edge tower • C = corner tower • Each must be calibrated in different ways, and first interior towers must be calibrated, then edge towers, then corner towers

3. Algorithm • 1st pass – this calibrates the inner towers only. Most steps implemented in Sebastien's code. Steps which are not yet implemented marked in red. • Loop over all events • Find highest tower in event • Check that max. amp. tower is isolated, was the trigger tower, and meets a minimum signal threshold • Correct amplitude of max. amp. tower for temperature • Correct amplitude of max. amp. for mean noise in tower • Done but system to get noise correction file from pedestal not known/ unwritten(?)‏ • Fill histogram for tower with corrected amplitude • Determine the correction factor for the tower by fitting the distribution of the corrected maximum amplitudes. Mean should be ~200 MeV. 200 MeV = <ADC> C

4. Algorithm • Write correction factors to a file • 2nd pass – edge towers. Not implemented at all. One option is to apply this to all towers as a check. • Loop over all events • Find highest tower in event • If highest tower is not on an edge or was not the trigger tower, continue • Check that max. amp. tower meets a minimum signal threshold • Look for a signal in neighboring interior tower only and if there is no signal in the neighboring tower, continue • Correct amplitude of max. amp. tower and neighboring tower for temperature • Correct amplitude of max. amp. and neighboring tower for mean noise in tower • Fill histogram for tower with correction factor for that event200 MeV = ADC1*C1 + ADC2*C2 for each event

5. Algorithm • Correction factor for edge towers is then given by C1 = <(200 MeV – ADC2*C2)/ADC1>When plotted this hopefully is Gaussian • Write calibration factors from second pass to a file. • 3rd pass – corner towers. Not implemented at all. Almost identical to edge towers, except two towers are neighbors • Loop over all events • Find highest tower in event • If highest tower is not on an edge or not the trigger tower, continue • Check that max. amp. tower meets a minimum signal threshold • Look for a signal in one of the neighboring corners tower only and if there is no signal in either neighboring tower, continue

6. Algorithm • Correct amplitude of max. amp. tower and neighboring tower for temperature • Correct amplitude of max. amp. and neighboring tower for mean noise in tower • Fill histogram for tower with correction factor for that event200 MeV = ADC1*C1 + ADC2*C2 for each event • Correction factor for edge towers is then given by C1 = <(200 MeV – ADC2*C2)/ADC1>When plotted this hopefully is Gaussian • Write calibration factors from second pass to a file.

7. Task distribution • Three possibly separable tasks • Modify Sebastien's code to fully implement algorithm • Calculate tower noise from pedestals • Calculate temperature correction factor • Status on these tasks? • Division of labor?

8. Implementing algorithm • Christine made a mistake which Elena caught. Christine was not looking at the distribution of the maximum amplitude in isolated towers. • Corrected plots from run 1838 at http://rhig.physics.yale.edu/~nattrass/ALICE/Beginning2July08/4Nov/ • Sample plot shown below

9. Implementing algorithm • From summary page http://rhig.physics.yale.edu/~nattrass/ALICE/Beginning2July08/28Oct/index.html • Looked at interior towers applying isolation cuts as if they were edge & corner towers and then looked at distribution of hits in towers which would be missing if they were edge & corner towers • Repeated, applying requirement that neighboring towers have hits in them

10. Implementing algorithm Edges Corners One hit Two hits