# Normalizing Heating Tally Data \[eV/src-particle\] to Power Density \[W/cm^3\]

**URL:** <https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003>\
**Category:** User Support\
**Created:** [March 4, 2024, 1:47pm UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003 "2024-03-04T13:47:48Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![MatthewFrick](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@MatthewFrick](https://openmc.discourse.group/u/MatthewFrick)\
**Post date:** [March 4, 2024, 1:47pm UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003/1 "2024-03-04T13:47:49Z")

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Hello Everyone,

I am currently collecting heating tallies in a cylindrical mesh and I am interested in normalizing these heating tallies [eV/src-particle] to power density [W/cm^3].

I have already looked at the 8.3 Section, “Normalization of Tally Results” but I am having trouble getting to power density [W/cm^3] from the normalization factor in that section.

The end goal is to determine the power peaking factor in a localized region of the core. Are there other ways of normalization that will allow me to determine the power peaking factor?

Any help would be greatly appreciated

Regards, Matthew

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**Author:** ![cclaro](https://avatars.discourse-cdn.com/v4/letter/c/9de053/32.png) [@cclaro](https://openmc.discourse.group/u/cclaro)\
**Post date:** [March 4, 2024, 5:16pm UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003/2 "2024-03-04T17:16:28Z")

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Its trivial really. I wish you the best of luck neutronics lead \<3

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**Author:** ![Daedalus](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/daedalus/32/2928_2.png) [@Daedalus](https://openmc.discourse.group/u/Daedalus)\
**Post date:** [March 4, 2024, 10:42pm UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003/3 "2024-03-04T22:42:41Z")

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k\_tally = (1.60218e-19)\*k\_tally # convert ev/source to joules/source  
k\_tally\_summed = np.sum(k\_tally)

norm = power\_level/k\_tally\_summed # source/s normalization factor

vol\_power = norm_k\_tally\_summed/(40_40_fuel\_length_np.pi\*fuel\_radius\*\*2) # units of joules/s/cm3 or watts/cm3 for each rod

Here k\_tally is the kappa\_fission tally which starts as a vector of values where each value represents on fuel cell. I convert it to joules from eV to start. k\_tally is then summed to get the total joules/source-particle for the core. norm is the normalization factor described by the 8.3 section where power level is in watts and is provided by the user. The volumetric power is then the summed kappa-fission tally times the normalization factor divided by the total fissionable volume over the entire core (in my case a 40x40 lattice of cylinders).

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**Author:** ![sshuddho](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/sshuddho/32/3327_2.png) [@sshuddho](https://openmc.discourse.group/u/sshuddho)\
**Post date:** [June 6, 2024, 7:32am UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003/4 "2024-06-06T07:32:19Z")

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@Daedalus, when I am multiplying norm with kappa\_fission, aren’t I just calculating the value of norm cancelling out kappa\_fission out of the equation?

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<div class="post-metadata">

**Author:** ![Daedalus](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/daedalus/32/2928_2.png) [@Daedalus](https://openmc.discourse.group/u/Daedalus)\
**Post date:** [June 6, 2024, 2:30pm UTC](https://openmc.discourse.group/t/normalizing-heating-tally-data-ev-src-particle-to-power-density-w-cm-3/4003/5 "2024-06-06T14:30:17Z")

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```auto
linear_power = k_tally*norm/(fuel_length/num_segs) # joules/s/segment_length (W/cm)

```

In the volumetric power check yes. The way I did it for individual rod linear powers was like this where you use the vector k\_tally instead of the summed version to get a vector of linear powers. k\_tally\_summed isn’t cancelled in this method.