Updates February 5 2016
Xiaqing Li
1
4He
Compton data analysis
• Formula for the differential cross section extraction:
•
•
•
•
•
χY: extracted yield
fabs : correction factor for target absorption
Nγ : number of incident photons
κ : target thickness [nuclei/cm2]
Ωeff: effective solid angle
2
HINDA effective solid angle simulation
•
• Ωsample = 4π
• N = total number of simulated events
• Nthr = number of events that deposit enough energy in core detector
3
Preliminary result
• This preliminary result is
suspicious since it
manifests the differential
cross section distribution
over theta.
• Check the physics generator
in Geant to fix this problem.
4
Preliminary result
• This preliminary result is
suspicious since it
manifests the differential
cross section distribution
over theta.
• Check the physics generator
in Geant to fix this problem.
5
HINDA effective solid angle simulation results
Ωeff in 4He run (by Mark Sikora)
Ωeff in 6Li Compton run (2012)
6
Back up slides
7
• N = 0.1 million
• N = 5 million
8
Compton scattering energy calculation
1
1
1
− =
1 − cos 𝜃
𝜔′ 𝜔 𝑚
𝜔′
=
𝜔
1+𝜔/𝑚(1−cos 𝜃)
• Energy of scattered gamma: ω'
• Energy of incident gamma: ω = 61 MeV
• Mass of target 4He: m = 3755.8 MeV
𝜃
𝜔′ (MeV)
40°
60.77
55°
60.58
75°
60.27
110°
59.70
125°
59.48
145°
59.25
159°
59.14
9