Discrepancies of detect card result

Dear expert,
I am doing simulation of HPGe detector using point source with detect scoring and I got 2 different result in two different condition.

  1. using detect card only, Efficiency is 5.414 E-2 CPS/Photon.
    2.using detect card with high probe and Rad decay transport, efficiency is 3.171 E-2 CPS/Photon.
    I attached my Input file please check it.

esl2nd hpge.flair (4.7 KB)
esl2nd hpge.inp (4.5 KB)

Dear User,

I was looking at your input, but I was not able to reproduce your results.
Could you please share the exact input/flair file for the two configurations you are running?

Thank you very much.
Kind regards,

I attached here the files please check it.
esl2nd hpge.flair (3.5 KB)
esl2nd hpge.inp (4.5 KB)
esl2nd hpge1.flair (655 Bytes)
esl2nd hpge.inp (4.5 KB)

Could you please attach the ‘esl2nd hpge1.inp’ file in order to be able to open the ‘esl2nd hpge1.flair’?

Thank you very much.

esl2nd hpge.inp (4.5 KB)

esl2nd hpge1.inp (4.5 KB)


From what I see in your input files, the physics cases are different: in one case you have a photon beam of 1274 keV while in the other case you have a 22Na source.

In the latter, you enable the radioactive decay of the 22Na. This means that you will have a source of photons with E=1274 keV from the beta+ decay of the 22Na to 22Ne. Therefore, a positron is also emitted in the decay. This positron will be annihilated in the media with the resulting emission of photons with 511 keV. Additionally, it can occur the simultaneous absorption of both photons (peak at E=1785 keV).

If you compare the two spectra from the provided input files you will see the differences described above. And this can explain the differences in the efficiency calculation.

I hope this solve the doubt on your results.

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