Modelization of the HIREGS III Ge spectrometer background



 



 


Observed and calculated background in the HIREGS unsegmented Ge detectors. The data are from the flight 94-95 and the calculations are for the continuum background. The beta decay components have been taken from Naya et al. (1996, N.I.M, A368, 832) and scaled with the ratio of the rates in the 198 keV line between HIREGS and HEXAGONE II.The photonic components have been estimated with Monte-Carlo simulations using the GEANT code.



Comparison of the calculated and the observed continuum background of HIREGS between 0.2 MeV and 1.2 MeV (PSD energy range). The estimated b- localized component is also shown. The ratio between the calculation and the measurement is presented in the bottom part. Numerical values are listed in the table below



Estimations of the fraction of total continuum background rate induced by b- localized decays. Two cases have been considered: ratio between the calculated beta component and total simulated continuum background, and,  ratio between the calculated beta component and total mesaured continuum background. Numerical values are listed in the table below (the rates are in counts s-1 cm-3 MeV-1).
 
 
 
E (MeV)
b- localized rate
calculated rate
measured rate
fb (b- calc./tot. calc.)
fb (b- calc./tot. meas.)
0.2
3.600e-02
1.000e-01
1.600e-01
3.600e-01
2.250e-01
0.3
3.800e-02
8.200e-02
1.100e-01
4.634e-01
3.455e-01
0.4
3.800e-02
7.000e-02
8.600e-02
5.429e-01
4.419e-01
0.5
3.600e-02
6.000e-02
6.800e-02
6.000e-01
5.294e-01
0.6
3.200e-02
5.300e-02
5.400e-02
6.038e-01
5.926e-01
0.7
2.800e-02
4.400e-02
4.700e-02
6.364e-01
5.957e-01
0.8
2.300e-02
3.800e-02
4.000e-02
6.053e-01
5.750e-01
0.9
1.750e-02
3.000e-02
3.300e-02
5.833e-01
5.303e-01
1.0
1.200e-02
2.300e-02
2.500e-02
5.217e-01
4.800e-01
1.1
8.400e-03
1.800e-02
2.000e-02
4.667e-01
4.200e-01
1.2
6.000e-03
1.500e-02
1.700e-02
4.000e-01
3.529e-01



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