[IMAS-3226] Adding new local divertor quantities in the SUMMARY IDS, …

[imbeauf]

…and precising some of the divertor local quantities definitions

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📚 Documentation preview 📚: https://imas-data-dictionary--268.org.readthedocs.build/en/268/

[github-actions]

Diff of generated Data Dictionary XML file

[DavidPCoster]

I think the following quantities are of interest

electron density
electron temperature
election energy flux
ion densities
ion temperatures
ion energy fluxes
electron + ion energy fluxes
total energy flux

with, for all of these, peak and strike point values

[hrdoktorx]

Adding @Simon-McIntosh to the reviewers as this change of definition will affect the Standard Names he is working on.

[github-actions]

Diff of generated Data Dictionary XML file

[olivhoenen]

This should not be merged as is, at least not in develop branch. The summary IDS is in active lifecycle and this is a major and backward incompatible change as far as summary/local/limiter is concerned.

[github-actions]

Diff of generated Data Dictionary XML file

[imbeauf]

This should not be merged as is, at least not in develop branch. The summary IDS is in active lifecycle and this is a major and backward incompatible change as far as summary/local/limiter is concerned.

Sorry, I made a mistake as I changed the type of the local/limiter structure (I don't know what happened). The idea of creating a new type specific for the divertor was precisely to leave the limiter unchanged. I have restored the initial limiter structure.

[imbeauf]

electron density electron temperature election energy flux ion densities ion temperatures ion energy fluxes electron + ion energy fluxes total energy flux

@DavidPCoster , what is the difference between "electron + ion energy flux" and "total energy flux" ? In the total, there is also some energy flux coming from the neutrals, and radiated power from elsewhere ?

[imbeauf]

Previously we had a quantity power_flux_peak in [W.m^-2]. I realize that the name is maybe incorrect, and I should declare it obsolescent and rename it as energy_flux_peak ? What do you think, @DavidPCoster , @hrdoktorx ?

[hrdoktorx]

power_flux_peak matches the naming convention from the divertors IDS. I would recommended keeping the nomenclature between the divertors and summary IDSs consistent. And match the DD definitions by the same occasion.

[Simon-McIntosh]

Previously we had a quantity power_flux_peak in [W.m^-2]. I realize that the name is maybe incorrect, and I should declare it obsolescent and rename it as energy_flux_peak ? What do you think, @DavidPCoster , @hrdoktorx ?

I agree that energy flux is the correct term. Power flux implies power crossing an area per second, so W / m2 / s

[DavidPCoster]

electron density electron temperature election energy flux ion densities ion temperatures ion energy fluxes electron + ion energy fluxes total energy flux

@DavidPCoster , what is the difference between "electron + ion energy flux" and "total energy flux" ? In the total, there is also some energy flux coming from the neutrals, and radiated power from elsewhere ?

Thinking about this a bit more, we could go

• the very detailed route (ion energy flux, electron energy flux, potential energy flux ... [I don't think this makes sense])
• or more based on the physics (plasma energy flux, neutral energy flux, radiation energy flux, total energy flux)

If we go for the 2nd option, experiments might provide only the total energy flux if the measurements are based on IR cameras or thermocouples, whereas the codes could fill the others and the total only if they have a model for radiation deposition in addition to the plasma and neutrals contributions

@hrdoktorx -- what do you think? Any other SOL modellers? [Finding the names of people was easier on the older system]

[hrdoktorx]

I'm agnostic on the change. Both methods will require similar amount of work from a coding point of view. Since the experimentally available quantity is only the net deposited energy flux, modellers are free to split whichever way is convenient to them as long as the comparison to experiments remains possible.

[imbeauf]

So far, the divertor IDS distinguish the following types of power falling on a divertor target:
divertor(i1)/target(i2)/power_convected
convecter, radiated, black body, neutrals, recombination_plasma, recombination_neutrals, currents

The WALL IDS, in its GGD description of energy fluxes, is even more detailed, see description_ggd(i1)/ggd(itime)/energy_fluxes, with fluxes per ion and neutral species ...

I suggest however to limit the content of the Summary IDS to the quantities that will most likely be queired by users (and avoid for instance explicit list by species ...).

So I am waiting for your specification to implement.