Estimating Total and Regional Energy Deposition

Scoring
1

Dear FLUKA experts,

I am interested in determining the total energy generated within the entire geometry and the proportion deposited in each individual region. I have been examining one of the .out files produced after the simulation,specifically, the ENERGY Density column in the Events by Region section.

Am I correct in assuming that the energy deposited in a given region E_i can be estimated using the formula:

E_i = \phi_i V_i

where \phi_i is the energy density and V_i is the volume of region i? If so, the percentage of total energy deposited in region i would be:

\%E_{\text{deposited}} = \frac{E_i}{\sum_i \phi_i V_i}

Is this assumption valid, or is it necessary to define a separate USRBIN scoring card for all regions (I have 75 regions in total) in order to obtain the energy deposition values correctly?

If the former approach is valid, what would be the recommended method to compute the associated statistical uncertainties from multiple .out files?

Thank you very much for your time and support.

Cheers,
Samuel

2

Not really, because - as you can read in the same table - the region volume is assumed to be 1 cm3 (unless you input all region volumes in the obsolete way indicated in the manual). So, as a matter of fact, the .out values are not energy density \phi_i, rather energy E_i deposited in the region.

You just need one USRBIN card applied to the whole region interval (from region #1 to region #75) to easily get average values of E_i over multiple cycles and respective statistical errors.

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3

Dear @ceruttif,

Thank you very much for your prompt response.

In retrospect, I realise that I had overlooked the more appropriate approach of using a USRBIN card to score energy deposition across regions. As a follow-up, do I need to multiply the scored energy values by the volume of each region, or is this unnecessary if I’m specifically interested in total energy deposited (as opposed to energy density)?

Additionally, regarding the ENERGY Density column I referred to earlier — does it provide any meaningful information for assessing energy deposition, or is it not intended for that purpose?

Thank you again for your valuable assistance.

Cheers,
Samuel

4

Both USRBIN by region results and .out ENERGY “Density” values give the total energy deposited in a region, thereby any further multiplication by the region volume is indeed unnecessary to the point of being wrong.

The .out ENERGY “Density” values are precisely intended to give a meaningful information in terms of energy deposition per region, but they just refer to the statistics of a single cycle, with no statistical error estimation.

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5

Dear @ceruttif,

I completely understand now. Thank you for the easy-to-follow explanation and for your time.

Cheers,
Samuel

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