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ukaea / PROCESS

PROCESS is a systems code at UKAEA that calculates in a self-consistent manner the parameters of a fusion power plant with a specified performance, ensuring that its operating limits are not violated, and with the option to optimise to a given function of these parameters.
https://ukaea.github.io/PROCESS/
MIT License
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Fusion power volume integration #766

Closed jonmaddock closed 1 month ago

jonmaddock commented 5 years ago

In GitLab by @mkovari on Oct 1, 2018, 11:30

The calculation of fusion power uses this formula:

       !  Fusion reaction rate (m3/s) is calculated in fint for each ireaction
       !  sigmav is the volume-averaged fusion reaction rate (m3/s)
       !  = integral(2 rho sigv(rho).ni(rho)^2 drho) / (deni**2)

The volume element is included in the 2*rho factor: $dV=2\pi r dr$

This seems a bit crude as it applies only for circular flux surfaces. It is true that in the core where the fusion takes place the local elongation and triangularity are small. Would it be practical to use a more accurate formula taking account of elongation of the flux surface?

jonmaddock commented 2 years ago

In GitLab by @mkovari on Jul 19, 2022, 13:21

Hi Alex @ajpearcey, As explained above, the integration of fusion power is only correct for circular flux surfaces. Correcting this would require knowing at least the elongation of all the flux surfaces (not just the LCFS). Obviously the basic 0D parts of PROCESS don't know this. Is there any way to get this information somehow?

jonmaddock commented 2 years ago

In GitLab by @ajpearcey on Jul 19, 2022, 14:15

I don't think there is for all flux surfaces. We would require some mapping between $\rho$ and $\psi(\rho)$ which would surely require a full equilibria to work form.

But if we switched from a circular flux surface to one that included elongation (or even the triangularity) based on calculations in the plasma_geometry module, could we find some linear approximation to generate $\kappa(\rho)$ and $\delta(\rho)$? I wonder if this could be done in a way that is applicable to many machine configurations?

jonmaddock commented 1 year ago

In GitLab by @mkovari on Aug 27, 2022, 20:54

Hi Sam, It would be good to implement this issue, but I don't know how - I have asked Alex if he can think of anything.

All the best, Michael Kovari

mkovari commented 3 months ago

In all JETTO runs, dV/drho is output in the signal profiles / DVEQ.

jmorris-uk commented 1 month ago

This is a discussion for a feature not a papercut or issue ready to be implemented. Moved to discussions here https://github.com/ukaea/PROCESS/discussions/3254