Multiple isotope source in a single input

I wanted to simulate a NaI detector crystal with multiple isotope sources. I was able to add Co-60 isotope using ‘HI-PROPE’ card but unable to add more isotopes like Cs-137 & Na-22 all together in a single input file. Please suggest how it is possible. NaI.flair (2.8 KB) NaI.inp (2.4 KB)

Thank You.
Utpal Bera

Dear Uptal,
many thanks for your question.

I think that the simplest way for you would be to make separate runs for each of the isotopes that you wish to study with your NaI detector. You can do this by adding #define directives and conditional directives which select the isotope that you specify in the HI-PROPE card like in the example below.

In the Flair Run tab you can then run different cases selecting one of the #define (e.g. one for Na-22, one for Co-60 and one for Cs-137)

The reason why I am suggesting this is that it is then easier to apply the correct normalization to the result that you obtain. In semi analogue mode (which you correctly used to simulate a radioactive source), the output of DETECT is expressed per primary event which, in the case of a radioactive isotope as source, is a decay event. So if you wish to obtain absolute numbers, you should multiply the result by the source activity: your Na-22, Co-60 and Cs-137 sources will have different activities (most likely), hence a different normalization should be used for each. You can then plot the contributions separately (properly normalized) or their sum which would give the spectrum of your multi-isotope source.

On this aspect note there is no need to add DCYSCORE for DETECT: as you might have seen in Flair, there is no possibility to select DETECT under the “Kind” entry of the card. On the contrary DCYSCORE must be used to associate other scorings (like RESNUCLEi, USRBIN, …) to a user defined decay time.

I hope this answers your question. Please let me know if you need help in setting up multiple runs and/or plotting the sum of the contributions directly using the Flair Plot tab.