1. T. Markiewicz / SLAC MAP at SLAC Working Meeting 2 July 2014
Comparison of Photon from v2 versus v7 masks in innermost VXD Layer at a Muon Higgs Factory
T. Markiewicz / SLAC
MAP at SLAC Working Meeting
2 July 2014

2. Masks v2 versus v7
2 July MAP at SLAC
T. Markiewicz

3. 320um Silicon Conversion/Scoring Planes
Barrel Detector
Radius (cm)
Half Length (cm)
VXD
5.5
20.5
Tracker
50.0
91.0
ECAL
131.0
200
Barrel Detector
Radius (cm)
Half Length (cm)
VXD
7.7
28.7
Tracker
50.0
91.0
ECAL
131.0
200
Endcap
Z (cm)
Rin (cm)
Rout (cm)
VXD
24.8
6.7
18.4
Tracker
92.0
25.2
53.3
ECAL
200.1
38.0
130.9
Endcap
Z (cm)
Rin (cm)
Rout (cm)
VXD
30.0
6.7
18.4
Tracker
92.0
25.2
53.3
ECAL
200.1
38.0
130.9
2 July MAP at SLAC
T. Markiewicz

4. FLUKA Photons v2 mask versus GEANT converted photons v7 mask
Time when photon produced by showering decay electron (all 9 Silicon layers in this plot)
V7 converted photon backgrounds = 12% v2 backgrounds
5100 x 2% = 102 to get background associated with one bunch
X100 to get background associated with one bunch
2 July MAP at SLAC
T. Markiewicz

5. Time and z of produced photon backgroundv7 v2
2 July MAP at SLAC
T. Markiewicz

6. z of produced photon backgroundv7 v2
2 July MAP at SLAC
T. Markiewicz

7. Z Distribution of Photons in Innermost Barrel VXD
Use this to get Peak/Average occupancy (Should also look at azimuth) v2 v7
First hit only
Inner VXD:
Conversion eff: 6581/1,121,001=0.587%
Hit Multiplicity = 89207/6581 =
2 July MAP at SLAC
T. Markiewicz

8. Time Distribution of photon hits on Inner VXD Barrel
time_parent
time_parent
time_child rel. to parent
time_child rel. to parent
2 July MAP at SLAC
T. Markiewicz

9. Time Distribution of photon hits on Inner VXD Barrel
time=time_parent+time_child
time=time_parent+time_child
Source of photons
Source of photons
2 July MAP at SLAC
T. Markiewicz

10. V7 Hit multiplicity (all layers)
Note that nh counts parent plus all children
2 July MAP at SLAC
T. Markiewicz

11. Hit Density Comparison
2 July MAP at SLAC
T. Markiewicz

12. Conclusions
Factor of 8 reduction in photons emanating from v7 mask relative to v2 mask
Hit density calculated in v2 via scoring and using a 2% photon to 1 e- hit conversion efficience
In v7 analysis, in innermost layer we see same hit density as ~x8-10 hits/converted photon compensate for reduced incident photon flux
Next steps:
Check v2 e+/e- versus v7 as
Check conversion efficiency
Check #/hits per converted photon and the spatial & time distribution of those hits
2 July MAP at SLAC
T. Markiewicz

13. Innermost VXD Layer: Separation between Hits
Set MaxHit=2
20 um bins
2 July MAP at SLAC
T. Markiewicz

14. Numerology for hits on Innermost VXD Layer
Set MaxHit=2
Inner VXD:
1,121,001 photons make a hit on this layer
There are a total of hits seen
6581 photons make one or more hits on this & other layers
In 5872 cases all the hits stay on this Inner VXD layer;
In cases the last hit in the n-tuple is on a different layer
1053 of 6581 (or 5872) events only have one e- hit on the layer
In 4819 of 5872 events, all the hits stay on the inner VXD layer
When >1 hit, the max. probability of separation between first and last hit is 1mm
Conversion eff: 6581/1,121,001=0.587%
Hit Multiplicity = 89207/6581 =
This is ~ 3.1x the mean number of hits when histogram truncated at 20 hits.
2 July MAP at SLAC
T. Markiewicz