1. Alignment Issues

2. January 6, 2006Maury Goodman2 Outline Reminder – The alignment problem still needs to be identified and solved, but need not delay charge ratio analysis Gap fixes Vulcan data no good Fields plots on sensitivity New delta-z plot

3. January 6, 2006Maury Goodman3 Gap Fixes Far detector realignment completed for Release 1.18 –2 cm bug in 1% of strips fixed –2 cm error in starting width in all modules fixed (related to the module gap model) Result – This did not cure the east-west charge ratio problem There may be other problems with release 1.18

4. January 6, 2006Maury Goodman4 Vulcan data Vulcan data extensively studied by Louis Barrett & Phil Schreiner Distance between Alner holes should be good to.2mm. Spread over 1 cm. –Conclusion – cannot be used to improve alignment

5. January 6, 2006Maury Goodman5 THF 2D Monte Carlo Investigated the effect of a bias in the curvature measurement which was 10% of the resolution. Started with perfect geometry in the vz plane, (used to study resolution of 1/p) Then added a bias, to determine alignment tolerances

6. January 6, 2006Maury Goodman6 Z V vzero Geometry Model of Scint Strips and Planes THF Sep 20, 05 α 5.54 cm 4.1 cm

7. January 6, 2006Maury Goodman7 Tom Fields 2D Monte Carlo Investigated the effect of a bias in the curvature measurement which was 10% of the resolution. Conclusions (Based on other plots not shown): random alignment tolerance is <3 mm in u,v, z systematic alignment tolerance on sagitta measurement is <2 mm.

8. January 6, 2006Maury Goodman8 +/- one sigma resolution

9. January 6, 2006Maury Goodman9 Conclusion – You can introduce a peak in the charge ratio versus muon energy distribution from a bias. We know we have a bias. random alignment tolerance is <3 mm in u,v, z systematic alignment tolerance on sagitta measurement is <2 mm.

10. January 6, 2006Maury Goodman10 Tape measurements z of each plane was measured with a tape measure at the bottom on each side. 3 starting points, (0S, 239N, 240S) The differences are plotted. Both supermodules seem fanned out. 3 cm!

11. January 6, 2006Maury Goodman11 Other measurements There is probably a need for other measurements, but we should figure out what we are going to do with them first.

12. January 6, 2006Maury Goodman12 Monte Carlo Problem We cannot introduce misalignment to the current Monte Carlo to study possible problems.