1. Outline
Analysis of some real data taken with the GLAST minitower (cosmic rays only).
Offline analysis software used.
Full Monte Carlo simulation using GLEAM with the minitower geometry.

2. Angular distributions
Black histograms: data.
Blue crosses: Monte Carlo.
Red line: expected distribution (CR flux + detector angular response).
Red dotted line is the geometrical upper limit on theta (~82 degrees), given the minitower aspect ratio.

3. TOT vs. theta
Average of TOT distribution increases as theta increases (the bigger the angle, the longer the path in the silicon).
Real data
Monte Carlo simulation

4. TOT vs. theta projected on XZ-YZ
Example of average TOT as a function of the polar angle theta projected on the XZ or YZ plane (real data). Distributions are shown for the X3 layer (i.e. strips oriented along Y axis!).
Along the Y axis: the bigger the angle, the bigger the charge released on a single strip.
Along the X axis: more complicate interplay between path length in the silicon and charge sharing.

5. TOT vs. phi
Average TOT as a function of the azimuthal angle (real data) is clearly oscillating:
Tracks along the strips direction: big TOT.
Tracks orthogonal to the strips: charge sharing.
Note the 90 degrees phase difference between layers X3 and Y3.

6. TOT vs. hit multiplicity
Average TOT as a function of the hits multiplicity (number of fired hits per event) shows a 2 (charge sharing on almost vertical tracks) confirmed by Monte Carlo simulation.
Real data
Monte Carlo simulation

7. Hitmaps Black histogram: data. Blue crosses: Monte Carlo simulation.
Red line: expected distribution for a “perfect” detector (not including the shadow effect of not active regions on ladder edges, which are very well reproduced by the Monte Carlo simulation).

8. Hitmaps
~ 200 strips not wire bonded.