3rd December 2003James Loken – Oxford University1 SCT X-ray Alignment Software A First Update

3rd December 2003James Loken – Oxford University2 X-ray Alignment  Current Methods  Simulation (of Hits)  and Calibration Beam positions  HitToStrip  Generate Calibration Beam Data  Increase speed by different use of Random and Gaussian  (real data could enter here)  StripToHit  Use Calibration Beam Data to Calibrate Strips  Reconstruction (from Hits)  Analysis  Future  Incorporate Position and Tilt sensors  Diagnostic tools for Problem Solving  Calibration of X-ray Gun

3rd December 2003James Loken – Oxford University3 Simulation  Loop over all 12 z positions  Generate beams (4) at 231 phi values (1/5 of dPhi of beams)  Loop over barrels 3 – 6  Intersect 4 beams with barrel radius  Find appropriate detectors and intersect with beams  Write accurate strip hits (and gun z/phi) to hit and calib lists  Write modules hit and calibration scanNo to scan list dPhi

3rd December 2003James Loken – Oxford University4 HitToStrip  Read Scan list for modules hit  Read hit list for hit and gun pars  Generate 10K strips with Gaussian for r-phi and u/v-phi dets (beam 0.5 mrad x 20 mrad (?))  Add 20% (?) random background strips  Generate 2K hits per strip for Calibration beam (20 mrad)  Include Strip Efficiencies for all strips (+/- 10% rms dist)  Use Gaussian function value, and Random for errors  Store as histogram(s)  Save histograms (8+) as root file  Repeat for each Scan (231 x 12)

3rd December 2003James Loken – Oxford University5 Random and Gaussian  Random.nextGaussian() - once/X-ray (10K)  20K r-phi and u-phi strips  4K background for both  600K calibration beam for both  624K total  x8 modules x231 scans (x12 z pos)  1.2 x 10**9 (x12 z pos) AND for x10 statistics, x10 calls!  Value: Gaussian fn. Error: Random - once/strip  45 r-phi and u-phi strips  0 background for both  300 calibration for both  345 total  x8 modules x231 scans (x12 z pos)  This is 1800 times faster. And for x10 statistics, same number of calls!

3rd December 2003James Loken – Oxford University6 Module Strip Data

3rd December 2003James Loken – Oxford University7 Module Strip Data(2)

3rd December 2003James Loken – Oxford University8 StripToHit  Read Scan list for modules hit  Find Root file  Find Histogram for each module  Search histogram (in each half) for largest peak  Find scan and histo for Calibration data  Correct strip histograms for Strip Efficiency  Fit limited range around peak to Gaussian  Extract peak value as accurate hit  Write accurate strip hit (and gun z/phi) to hit list  Repeat for each module  Repeat for each Scan (231 x 12)

3rd December 2003James Loken – Oxford University9 Results for No Effic, No Calibration

3rd December 2003James Loken – Oxford University10 Results for With Effic, No Calibration

3rd December 2003James Loken – Oxford University11 Results for With Effic, With Calibration

3rd December 2003James Loken – Oxford University12 …and Barrel 4

3rd December 2003James Loken – Oxford University13 …and Barrel 5

3rd December 2003James Loken – Oxford University14 …and Barrel 6

3rd December 2003James Loken – Oxford University15 Conclusions  A good start has been made  More work has been done  Some of the remaining work to be done:  A good Calibration of the Gun is needed  First attempts at a new method not good enough.  A good method must be found, H/W built, LabVIEW S/W written, data taken (DAQ working) – June 2004  Laser & Tilt Sensors used – Sept 2004  Integration of Online S/W (LabVIEW, DAQ, Sensors) – Nov 2004  EndCap, full H/W & S/W programme – May 2005??  Extraction of Detector positions – a few hours later!  Other work (Diagnostic tools, tests, studies) – in between times