1. Development of the European Scanning System Progress Report Development of the European Scanning System Cristiano Bozza – European Emulsion Group - LNF, Oct 2002

2. Development of the European Scanning System: progress report The Mikrotron camera with the Photobit CMOS sensor can now work @ 87 fps The field of view (excluding overlapping regions) is 350 × 270  m 2 We can reach a speed as large as  14 cm 2 /h with 16 layers sampling Obtaining such performance is not straightforward: Since the thread timeslice under Win2k is 10 ms, and the camera cycle time is 11.4 ms, 1/3 of the fields is missed because of the software architecture (the frame grabbing is started by the host PC CPU) Actually, we only get 58 of the 87 fps...

3. This was expected, and we have been working on an asynchronous frame grabbing model which has now passed all technical tests An asynchronous version of the scanning module (“VertigoScan3”) is already being debugged, and is expected to be ready for production within 2 weeks Frame 1 Frame 2 Frame 3 DAQ Thread Other Thread DAQ Thread Frame 2 is missed because of the time structure of the present DAQ software Development of the European Scanning System: progress report

4. Old (Production version) time structure of the DAQ cycle Image grabbing (Camera) Image Processing (Genesis) Clustering (PC CPU) Tracking (PC CPU) XY Motion Z Motion The command to grab each frame is issued by the PC CPU Clustering must stay in sync with grabbing CPU idle for > 50% of the time, whereas tracking may slow down DAQ Avoid disk swapping (can’t use standard memory allocation) The thread timeslice is 10 ms... Good for 60 fps (16.7 ms cycle) but not for 87 fps (11.4 ms) Frames could be missed… Rough Z readout Field N Development of the European Scanning System: progress report

5. New time structure of the DAQ cycle Image grabbing (Camera) Image Processing (Genesis) Clustering (PC CPU) Tracking (PC CPU) XY Motion Z Motion Field N Field N-1 Genesis programming for next field (PC CPU) Trajectory data readout (PC CPU) FlexMotion programming for next field (PC CPU) Field N The CPU pre-loads the commands to grab frames and to readout several Z samples At each field, only a “start” command is issued by the CPU Longer time available to perform tracking Disk swapping does not cause missing frames No problem with faster cameras Very precise Z readout Larger memory occupancy on Genesis nodes The core cycle needs reshaping (1 field of view delay) Development of the European Scanning System: progress report

6. A brick was exposed in Sept 2002 to test vertex location In Salerno, we got 5 sheets + 6 CS First task: Sheet to sheet intercalibration Second task: CS intercalibration with sheet #1 Third task: CS intercalibration with Si-tracker Fourth task: Scanback of possible interaction product tracks up to vertex Unfortunately, thickness  30  m AGAIN! Development of the European Scanning System: progress report

7. Sheet to sheet intercalibration 4 zones 1 cm 2 each were scanned on each sheet Pattern matching was then applied from each sheet to its nearest neighbours For each sheet, the 3 zones with the highest matching numbers are selected out the 4 to compute the alignment parameters This work was successfully completed for all 4 zones on all 5 sheets by using the Salerno prototype with provisional optics, no automatic light control and a CHORUS camera (Hitachi KP-F110 @ 30 fps) Scanning speed  4 cm 2 /h Development of the European Scanning System: progress report

8. Sheet to sheet intercalibration 200  400 tracks match per each zone The resulting precision is satisfactory, and even better than needed for the scanback phase Development of the European Scanning System: progress report

9. First task: Sheet to sheet intercalibration Second task: CS intercalibration with sheet #1 Third task: CS intercalibration with Si-tracker Fourth task: Scanback of possible interaction product tracks up to vertex Sheet to sheet intercalibration OK In progress Strategy under study... Scanback track disappearance? Multitrack crossing? Both? Development of the European Scanning System: progress report