Geant4 Simulations for the Radon Electric Dipole Moment Search at

Absolute Efficiency (%)
15
10
5
µMetal Thickness
0.10 cm
0.25 cm
0.50 cm
0.75 cm
1.00 cm
0
100 1000 10000
γ-ray Energy (keV)
Figure 4.3: Geant4 generated absolute efficiency curves for a ring of eight GRIFFIN
detectors in the highest efficiency mode (forward configuration) including the full
RnEDM setup (EDM cell, oven and magnet) with various thicknesses of µMetal.
Timing information was extracted from γ-ray energy-time matrices. Figure 4.4(b)
illustrates a three-dimensional view of a small energy and time slice for one detector
in the simulation presented in Figure 4.4(a). The dimension of the γ-ray energy-time
matrices were 4096 by 4096, where the γ-ray energies were binned into 1 keV bins
resulting in a maximum energy of about 4.1 MeV. The resolution of the time bins
was flexible and thus optimized for the length of each simulation. Generally the times
were binned into 10 ms, resulting in just over 40 seconds of simulation time.
4.2 Frequency Signal
The frequency signal can be clearly seen in the three-dimensional Figure 4.4(b).
To generate a spectrum of this signal, energy gates were placed around the γ-ray
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