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PXL geometry update (2013-04-16)

Updated on Sun, 2013-05-05 10:31. Originally created by bouchet on 2013-04-16 16:57.
From Flemming :
  1. Change stepping accuracy to 1 micron
  2. Change ladder cables : implementation both Al and Cu in a proper way. Default is Cu for y2013
  3. active thickness of Si = 18 microns
A) Material differences
I used StarBASE to plot the radiation length with the following config :
const Float_t eta_min = -2.0;  // min pseudorapidity
const Float_t eta_max = +2.0;  // max pseudorapidity
const Float_t deta    = 0.2;  // size of etabin
const Float_t phi_min =-180.000; // min phi (in degrees)
const Float_t phi_max =+180.000; // max phi (in degrees)
const Float_t dphi    = .5; // size of phibin (in degrees)
const Float_t nsample = 4.0;   // number of tracks / bin
B) PXL as a whole : PXMO volume
1) default geometry (DEV)

2) updated geoemtry (Flemming)


C) Silicon mother : PXSI volume
1) default geometry (DEV)

2) updated geometry (Flemming)


D) Si active : PLAC volume
1) default geometry (DEV)

2) updated geometry (Flemming)


 
COMPARISON btw THE 2 GEOMETRIES
a) PXMO volume : all PXL 

b)LADR volume : 1 ladder

c)PXSI : mother silicon

d)PLAC :active silicon
e)ALCA : cable


TRACKING EFFICIENCY 

a) simulation setup
  1. 1000 events
  2. 1 muon/event
  3. Pt =1.0GeV/c
  4. |η|<1
  5. Φ=1.7
b) result
Default geometry :
# events : 1000
# events with PXL hits =0 or >3  : 15
# events with PXL hits =1  : 35
# events with PXL hits =2  : 941
# events with PXL hits =3  : 9
# events with PXL hits used =2 for PXL hits =2  : 927
Efficiency (# of events with 2PXL hits used in tracking / # of events with 2 PXL hits) = 927/941 = 98.5%


Updated geometry :
# events : 1000
# events with PXL hits =0 or >3  : 6
# events with PXL hits =1  : 0
# events with PXL hits =2  : 979
# events with PXL hits =3  : 15
# events with PXL hits used =2 for PXL hits =2  : 831
Efficiency (# of events with 2PXL hits used in tracking / # of events with 2 PXL hits) = 831/979 = 84.8%


DCA RESOLUTION
1) default geometry : y2013: CVS
2) updated geometry : from Flemming with 
LADR_version = 1 means Material name = Cu Cable for the cables (ALCA volume)

    <Mixture name="matCuCable" dens="4.37" >
    <Component name="Cu" a="63.54" z="29" w="0.802"/>
    <Component name="kapton" a="12.767" z="6.36" w="0.198"/>
    </Mixture>

as compared to the default geoemtry
 <Material a="26.98" z="13" name="medAlCable" dens="2.7" radl="23.7"/>

3) results
simulation is 4.5k events with 20pions/event

a) default geometry


at Pt =1GeV/c,      pointing resolution ~ 27-30 microns
at Pt = 0.5 GeV/c ,pointing resolution ~ 50 microns
plateau  < 10 microns for high Pt

b) updated geometry



at Pt =1GeV/c,      pointing resolution ~ 45 microns
at Pt = 0.5 GeV/c ,pointing resolution ~ 65 microns
plateau  ~30 microns for high Pt

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