Hi,

I wanted to ask for confirmation. when I get a dose value from usrbin in a region, the value is normalized by region and primary, so I have to divide it by the area and material density of the region, right? And then if I am considering a source of a certain radionuclide, the primaries are the activity in Bq per seconds, and should I multiply this value with the one obtained?

Dear Andrea,

In the case of a USRBIN scoring with the type Region, the results must be divided by the regionâ€™s volume to get the expected units.

When using a radioactive source with a semi-analogue option, a primary would be a single decay (plus all the daughters in equilibrium), so the results needs to be multiplied by the activity of the original isotope.

Cheers,
David

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So if I am simulating a decaying radionuclide, the dose I obtain in the region must be divided by the volume of the region itself and multiplied by the original activity. Doesnâ€™t the density of the region have an impact? And then if I wanted to obtain a measurement in Gy/(h*Bq) from the FLUKA dose result, then I would have to divide the result by the volume, multiply it by 1.6e-7 so as to pass into Gray and finally multiply by 3600 to obtain a dose over time, right?

Dear Andrea,

For dose FLUKA scores the deposited energy in the region divided by the density, which gives [GeV*cm3/g/primary], thus you need to divied by the volume of the region (Note: If you are using the standard USRBIN scoring with a binning, the division is done automatically).

If you done the division by the volume and multiplied the results with `1.602176462E-7`, then you get [Gy/primary] = [Gy/decay]. You need to multiply this with the actual activity of the source [Bq] = [decay/s] to get [Gy/s] multiplying this with `3600` gives [Gy/h].

Cheers,
David

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Perfect thank you very much. One last question, if I wanted to obtain Gy/(h*Bq), what conversion factor should I use?

Hi Andrea,

maybe Iâ€™m missing something, but [Gy/h/Bq] is just a conversion factor between the dose and activity (for a specific source/geometry, etcâ€¦), obtainable with a simple division.

But if you expand the unit, you simply get [Gy/3600 decays].

Cheers,
David

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Yes, what I would like to do is verify some values â€‹â€‹declared in ICRP 107 with FLUKA. So I would like to understand how to arrive at a value in Gy(h*Bq).

Dear Andrea,

you need to multuply the FLUKA results [GeV/g] with `1.602176462E-7` and `3600` to get [Gy/h/Bq].

Cheers,
David

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Ok, if instead I am trying to find the dose emitted by a semi-analogue Con Iodine source, how can I measure only the dose emitted by the decay of iodine into Xenon without also considering the decay of Xenon.

Hi Andrea,

see this post:

Cheers,
David

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