1. M. LefebvreATLAS LAr week, November 19th 20021 HEC-EMEC beam test data analysis Filtering weight synchronization and timing issues TDC timing Cubic timing Digital filtering TDC synchronization cubic synchronization LArDigitalFiltering Michel Lefebvre University of Victoria Physics and Astronomy ATLAS LAr week 19 November 2002

2. M. LefebvreATLAS LAr week, November 19th 20022 TDC timing

3. M. LefebvreATLAS LAr week, November 19th 20023 TDC timing 25 ns 0 ns wrap-around-constant wac = 770 for run 13302, wac_epi triggers 25 ns should be about flat

4. M. LefebvreATLAS LAr week, November 19th 20024 TDC timing There are three possible wac trigger types trig_wac_c(trig_daq_e and not a bad trigger) trig_wac_epi(trig_daq_epi and not a bad trigger) trig_wac_mu(trig_daq_muand not a bad trigger) Each event is associated with only one wac trigger. In principle, a different wac value is associated with each wac trigger. Also, wac values change during a run period. The wac values can be obtained from the data, and must be tabulated. The tdc phase should be obtained this way: which yields

5. M. LefebvreATLAS LAr week, November 19th 20025 TDC timing The following is what is currently implemented in the code: where which yields where wac ref is one of the wac This was found to work in the past for some runs where wac_epi and wac_c where present at the same time. I suspect this was to correct for different T 0 (see later) for different trigger types It is not clear whether this is still relevant or not. This should be checked by comparing the tdc phase corrected pulse shape for wac_c and wac_epi triggers taken close in time. ?

6. M. LefebvreATLAS LAr week, November 19th 20026 TDC timing and pulse shape for time slice i, position at time if cubic fit finds peak correctly, then this curves is maximum at a height of 1.

7. M. LefebvreATLAS LAr week, November 19th 20027 not flat wrap-around-constant wac_epi  1200 for run 12645, wac_epi triggers example of bad TDC behaviour TDC timing

8. M. LefebvreATLAS LAr week, November 19th 20028 TDC timing and pulse shape for time slice i, position at time example of bad TDC behaviour

9. M. LefebvreATLAS LAr week, November 19th 20029 Cubic timing for time slice i, position at time if cubic fit finds peak correctly, then this curves is maximum at a height of 1 AND t=0 adc-ped > 50

10. M. LefebvreATLAS LAr week, November 19th 200210 Cubic timing for time slice i, position at time example of bad TDC behaviour in this case there are two different timings… …but the cubic timing is of good quality adc-ped > 50

11. M. LefebvreATLAS LAr week, November 19th 200211 Cubic timing quality adc-ped at peak(cub) channel 45

12. M. LefebvreATLAS LAr week, November 19th 200212 Digital filtering weight parameters filtering weights apply weights T dig S dig  j0j0 raw samples for each channel, we need  the digital filtering phase,  [0,  ) j 0 weights to be applied to samples j 0 to j 0 +4

13. M. LefebvreATLAS LAr week, November 19th 200213 int and mod

14. M. LefebvreATLAS LAr week, November 19th 200214 Digital filtering: TDC synchronization Let then set where i 0 is a fixed sample number then This procedure, in principle, yields for all channels with sufficient data in them With the current TDC correction implementation, should be independent of trigger type. With recent TDC problems, this is not clear anymore. ?

15. M. LefebvreATLAS LAr week, November 19th 200215 Digital filtering: TDC synchronization for time slice i=j 0 +n (n = 0,1,2,3,4) position at time run 13302, k=45, weights 020814 if digital filtering finds peak correctly, then this curves is maximum at a height of 1 this curves also shows the part of the signal used to make the weights… adc-ped > 50

16. M. LefebvreATLAS LAr week, November 19th 200216 Digital filtering: TDC synchronization max at 1.04 max at 1.00 run 13302, k=45, weights 020814

17. M. LefebvreATLAS LAr week, November 19th 200217 Digital filtering: TDC synchronization if T 0 is off by 5 ns, then the reconstructed signal height is off by about 4% run 13302, k=45, weights 020814

18. M. LefebvreATLAS LAr week, November 19th 200218 Digital filtering: TDC synchronization depends on k and on the weights parameter file used example: run 13302, trigger wac_epi, weights 020814weights 020901weights 020902 weights 020911weights 020912 these weights parameters file are currently synchronized for k=45 and i 0 =5 for run 13302

19. M. LefebvreATLAS LAr week, November 19th 200219 for time slice i=j 0 +n (n = 0,1,2,3,4) position at time Digital filtering: TDC synchronization run 12745, k=45, weights 020814 to do a good job one would need to analyze the two types of timings separately… example of bad TDC behaviour adc-ped > 50

20. M. LefebvreATLAS LAr week, November 19th 200220 Digital filtering: cubic synchronization Let then set where i 0 is a fixed sample number then where where k 0 is a fixed reference channel k’ is the channel used for cubic synchronization of an event in principle, can be obtained from the data by analyzing cubit fit signal timing. It is sensitive to the signal peaking time and rise time differences between channels This procedure, in principle, yields for all channels with sufficient data in them It should not depend on trigger type. ?

21. M. LefebvreATLAS LAr week, November 19th 200221 for time slice i=j 0 +n (n = 0,1,2,3,4) position at time Digital filtering: cubic synchronization run 13302, k=k’=k 0 =45, weights 020814 if digital filtering finds peak correctly, then this curves is maximum at a height of 1 this curves also shows the part of the signal used to make the weights… adc-ped > 50

22. M. LefebvreATLAS LAr week, November 19th 200222 Digital filtering: cubic synchronization depends on k, k 0 and on the weights parameter file used weights 020814weights 020901 example: run 13302, trigger wac_epi,

23. M. LefebvreATLAS LAr week, November 19th 200223 for time slice i=j 0 +n (n = 0,1,2,3,4) position at time Digital filtering: cubic synchronization here no need to worry about the two types of timings… example of bad TDC behaviour run 12745, k=k’=k 0 =45, weights 020814 adc-ped > 50

24. M. LefebvreATLAS LAr week, November 19th 200224 Note that is sensitive to physics signal rise and peaking times, while is sensitive to the calibration signal start times. Digital filtering: synchronization Note that the cell-to-cell differences of and should be the same because the cubic timing is done with respect to a fixed channel k 0 Summarizing, we could consider ? It should be independent of trigger type. ? where k 0 is a fixed reference channel k’ is the channel used for cubic synchronization of an event With the current TDC correction implementation, should be independent of trigger type. With recent TDC problems, this is not clear anymore. ? should not depend on trigger type. ?

25. M. LefebvreATLAS LAr week, November 19th 200225 Finding averaged over many channels looks promising Digital filtering: LArDigitalFiltering Currently, LArDigitalFiltering has an implementation assuming In the job options file, one can set k’ is the channel with highest cubic signal in the event Currently, in the amplitude weights parameter file, there is provision for How many run ranges do we need to consider? ? ? Need to obtain