Download BTeV Pixel Meeting, 01/15/01

JC and Marina
01/15/01
More Results From Simulation
 Equivalent track angle of Lorentz effect
 Comparison with ATLAS magnet results
 Effective temperature in diffusion constant
 Angular fit of  distribution
Lorentz Angle
Lorentz angle is not a
constant along z, shown
are overall effects
Larger bias voltage
 Larger E field
 Smaller mobility
 Smaller Lorentz angle
Syracuse University
2
Jianchun (JC) Wang
Lorentz Angle Comparison
MC
ATLAS
MC
ATLAS
MC
ATLAS
MC
ATLAS
Uapplied(V)








Udepletion(V)








deffective(m)








Lorentz()








Magnetic field: 1.4 Tesla
Udepletion is calculated with effective thickness of the sensor
Syracuse University
3
Jianchun (JC) Wang
Diffusion Constant
Einstein equation:
D=kT/q
Reduce Teff from 390K to 300K

Reduce fraction of doublet by 1.4%
Syracuse University
4
Jianchun (JC) Wang
Angular Fit With  Distribution
FPIX0-Pstop
Normal Incidence Data
 MC: 0.5 interval, interpolation
between points
 Normal incident data:
 = (1.77  0.09)
Syracuse University
5
Jianchun (JC) Wang
Angular Fit With  Distribution
FPIX0-Pstop
5° Data
15° Data
10° Data
20° Data


Syracuse University
6
Jianchun (JC) Wang
Detector Inclination Angle
0
5
10
15
20
30
Minuit Angle ()
0.25
6.00
11.0
15.9
21.1
30.4
 Fit Angle ()
1.77
7.50
12.6
16.4
20.1
N/A
Nominal Angle ()
 In MINUIT fit, the beam is assumed to be normal incident on the
first SSD, the overall rotation of the detector can not be fitted.
 The error from the fit is about 0.1°, which should be smaller than
error from MC model.
 For large angle, the  fit is not very sensitive to angle.
 We can consider that the spectrometer is at 1.5° to the beam
direction.
Syracuse University
7
Jianchun (JC) Wang
Sensitivity of  Fit
FPIX0 Pstop at 20
The shape of  distribution at
large angle is not as sensitive to
track angle as at small angle
Syracuse University
8
Jianchun (JC) Wang
Sensitivity of  Fit
Angular Sensitivity
of  Distribution
Syracuse University

9
Jianchun (JC) Wang
Summary
 The Lorentz angle generated agrees with ATLAS results
 The effect of effective temperature on diffusion is small
but may need to be considered
 The fit of  distribution shows that the spectrometer is at
1.5 degree with respect to beam direction
Syracuse University
10
Jianchun (JC) Wang
Effect of Signal Coupling
 A simple linear coupling
between neighbor rows
 Smearing effect of linear
coupling can be taken away
with  correction
 Small coupling (5-10%)
improves the resolution
Syracuse University
11
Jianchun (JC) Wang
Effect of Signal Coupling
A simple linear
coupling between
neighbor rows
Syracuse University
12
Jianchun (JC) Wang