IC calibration

1
IC calibration
H. Avakian JLAB Nov 12 2003

• Equalization of IC prototype with cosmic muons
• Calibration with DVCS photons

2
Cosmic muon test for IC

• Count rates for horizontal muons

I 1 ev/cm2/min cos2q
cos2q well describe the shape up to 80o I(80o)
0.03 ev/cm2/min
I(90o) I(80o)/2
Esimated time for 100 events in S1cm2
5 days
3
Cosmic muon test setup for the IC prototype
Setup from Youri Sharabian
4
IC calibration with DVCS photons
Detecting ep in ep -gt epg

• Energy distribution of DVCS photons
• Angular/coordinate resolutions
• Fraction deposited in a central block from MC

e
g
p
5
Energy distribution of DVCS photons
(GeV)
(degree)
High energy photons with almost constant with
angle average energy (4.5 GeV)
6
Checks with e16 data
qlt14o
3ltqlt10o
10ltqlt14o
E16 data in very good agreement with the DVCS MC
(curves)
7
Checks with e16 data
Photon energy in e16 and DVCS MC
Proton momentum in e16 and DVCS MC
8
Angular/Coordinate resolution of DVCS photons
Photon position in IC defined by 2mm
9
Energy resolution and exclusivity
IC energy resolution 100 MeV
10
Summary

• Prototype equalization with cosmic muons
• Energy calibration of IC with DVCS (BH) photons

• MC studies of IC to define the fraction of energy
  in the central block and total of 9.
• More MC studies of coordinate resolution of IC