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54 5 Scintillator upgrade
event ID track ID particle Ei Edep x process step
6 1 gamma 500.00 0.00 31.83 compt 10
6 1 gamma 202.62 0.00 31.55 compt 10
6 1 gamma 131.54 0.00 15.92 compt 10
6 1 gamma 130.54 0.00 0.00 trans 10
6 4 e- 0.991 0.99 15.92 eIoni 10
6 3 e- 71.09 71.09 31.55 eIoni 10
6 2 e- 297.38 152.73 31.93 eBrem 10
6 2 e- 108.59 108.59 31.90 eIoni 10
6 5 gamma 36.06 1.56 25.24 phot 10
6 6 e- 34.49 34.49 25.24 eIoni 10
Table 5.1: Detailed output from simulation ”ScintBlock” of one 500 keV
photon in NaI, whereas y and z values of interaction points are missing
in this list.
other) on a scintillator block with 1 m lateral length and 21 different
width, ranging from 1 mm to 1 m was examined. Thereby photons with
10 different energies from 200 to 2000 keV were initialised. Due to the
arguments from chapter 4.1.3—“Scintillating materials” only NaI, CsI,
BGO and CWO crystal were considered.
For every data file, the total amount of interacting photons and the fullenergy
events were counted.
RESULTS
In table 5.2 the peak and total absorption efficiency for scintillators of
different width for different photon energies, which was obtained with
this simulation, is listed. The peak absorption efficiency is the efficiency
for absorbing the full energy of the incident photon and the total
absorption efficiency is the total efficiency of the initial photon for interacting
with the scintillator material. This was mapped for incident
1200 keV photons, as can be seen in figure 5.1. The total and peak efficiencies
of the four scintillators are shown in A—“FIRST APPENDIX”
in figure B.1 - B.7.
NaI has the smallest density of these scintillators and correspondingly
the smallest absorption efficiency. CWO has higher density but a
smaller effective atomic number Zeff than BGO. This leads to different
total and peak efficiencies for BGO and CWO. The efficiencies depend
on the density and atomic number of the absorber material and
the energy of the initial photon.