Pixel Testbeam Analysis Results


(05/26/04)

There are 8 planes in the system. Locations and orientations of planes had been adjusted to have better alignment. The plane/slot IDs are 3, 4, 5, 7, 9, 10, 11 and 13. Planes 3 and 11 are Y planes and the rest are X planes. Planes 7 and 13 are perpendicular to the beam direction and the other X planes are slanted.

Runs 1130 - 1133 were taken at this condition. Run 1133 is the largest and thus is used to align the system. In this run there are total 22042 events. As we have enough planes I add in track formation the Y window. In total 1163 tracks are formed. And 745 good tracks with at least 7 hit planes are saved in ntuple file. The mechanical or optical alignment seems working great. With the geometry parameters optimized after software alignment, the effective space coverage of all planes (max row = 100) are listed in the table.

Plane/Slot X range (cm) Y range (cm)
SPD_Y 3 (-0.41, 0.27) (-0.20, 0.30)
SPD_X 4 (-0.32, 0.18) (-0.48, 0.20)
SPD_X 5 (-0.25, 0.24) (-0.44, 0.24)
SPD_X 7 (-0.19, 0.31) (-0.38, 0.30)
SPD_X 9 (-0.31, 0.18) (-0.39, 0.29)
SPD_X 10 (-0.19, 0.30) (-0.41, 0.27)
SPD_Y 11 (-0.32, 0.36) (-0.29, 0.21)
SPD_X 13 (-0.20, 0.30) (-0.36, 0.32)
It would be better that certain planes be further adjusted by 1 mm, but it is unrealistic. Current alignment is considered to be good enough.

The data corruption still exists but only one word out of 22042 hits. It is associated with plane 3 if this ID is not corrupted. The threshold resistors had been modified, I believe. The amount of noise hit, however, has increased.

Some useful files:

  1. run01133.ps.
  2. tb_geometry_1133.dat, the geometry parameters aligned using run 1133.
  3. dump_1130.dat
  4. dump_1132.dat
  5. dump_1133.dat, events with all hit planes.