RE: [fluka-discuss]: Dose from multiple sources

From: Maciak Maciej <>
Date: Mon, 26 Aug 2019 07:08:14 +0000

Dear Luigi,

Thank you for your e-mail, it confirmed my idea. Of course my simulation are based on assumptions you wrote – in general I’m interested in the total dose absorbed in the volume but the distribution will be valuable in comparison with the microscopic images of the target. To analyze the spatial distribution of the dose in this case and obtain the dose in Gy per decay, I should multiply the USRBIN value by the number of microspheres (and of course 1,6E-7). Am I correct?

Best regards,
Maciek M.

From: Luigi Salvatore Esposito []
Sent: Friday, August 23, 2019 5:57 PM
To: Maciak Maciej
Subject: Re: [fluka-discuss]: Dose from multiple sources

Dear Maciak,
assuming that there are N microspheres all with the same activity A, them you need to normalise dose with the factor N x A.
As side note, the logic implemented in the source routine is valid only if all micro-spheres have all the same activity.

Finally, with such a small volume, you are probably only interested to the dose deposited in the whole target.
With this respect, I just want to add that you are averaging the contribution of the micro-spheres, as suggested by the enclosed plot.

Hope this could answer your questions.
Best luigi


On 23 Aug 2019, at 12:56, Maciak Maciej <<>> wrote:

Dear FLUKA Users,

I would like to estimate the dose deposited in the thin water microbox containing several Y-90 microspheres. I used SOURCE user-routine to sample the coordinates of the spheres and it works fine. I used USRBIN detector to score DOSE in single bin which has the same dimensions as water box and I got the dose per decay according to the manual. I ran two simulation with different number of spheres located in the same volume and I got the same result. What is the reason of such behavior? Or maybe because I sample the sphere location I should multiply the result by the number of spheres to normalize according to the number of decays? It is not clear to me what in this specific case mean 'per decay'?

Best regards,
Maciej Maciak

Radiological Metrology and Biomedical Physics Division
National Centre for Nuclear Research
Andrzeja Sołtana 7, 05-400 Otwock-Świerk<>

You can manage unsubscription from this mailing list at

(image/png attachment: image002.png)

Received on Mon Aug 26 2019 - 11:28:08 CEST

This archive was generated by hypermail 2.3.0 : Mon Aug 26 2019 - 11:28:10 CEST