tau_e_h98, tau_e_ds03 are calculated incorrectly (?)

[daveweisberg]

In the calculation for tau_e_h98 (and also tau_e_ds03):

function tau_e_h98(eqt::IMAS.equilibrium__time_slice, cp1d::IMAS.core_profiles__profiles_1d, cs::IMAS.core_sources)
    total_source = total_sources(cs, cp1d)
    total_power_inside = total_source.electrons.power_inside[end] + total_source.total_ion_power_inside[end] - radiation_losses(cs)
    isotope_factor =
        integrate(cp1d.grid.volume, sum(ion.density .* ion.element[1].a for ion in cp1d.ion if ion.element[1].z_n == 1.0)) / integrate(cp1d.grid.volume, sum(ion.density for ion in cp1d.ion if ion.element[1].z_n == 1.0))

    R0, B0 = vacuum_r0_b0(eqt)

    tau98 = (
        0.0562 *
        abs(eqt.global_quantities.ip / 1e6)^0.93 *
        abs(B0)^0.15 *
        (total_power_inside / 1e6)^-0.69 *
        (ne_vol_avg(cp1d) / 1e19)^0.41 *
        isotope_factor^0.19 *
        R0^1.97 *
        (R0 / eqt.boundary.minor_radius)^-0.58 *
        eqt.boundary.elongation^0.78
    )
    return tau98
end

the power equation for "total_power_inside" ignores all losses due to radiation. However, according to Stambaugh 2011 eqn. 98 it is appropriate to include losses due to Bremsstrahlung radiation since this is new feature of burning plasmas. This is indeed what GASC does, and so for an apples-to-apples comparison it would make sense to do the same in FUSE.

[TimSlendebroek]

To expand on the discussion we had earlier it depends on what impurity species you have and what the electron temperature looks like if I take Nan's ITB case for FPP as example line radiation in the core is greater than the brehmstralung so the argument that the line radiation is always only present at the edge compared to brhem doens't seem to hold

dd,ini,act = FUSE.init(:FPP,version=:v1_demount,init_from=:ods);

[TimSlendebroek]

If we want to follow the rationale for accounting for radiation losses inside the core region for the confinement scalings I would suggest only subtracting off the sum of the radiation at the edge which wouldnt' be hard to do in FUSE.

What \rho_tor_norm would you consider the edge for this confinement scalings @daveweisberg ?

[TimSlendebroek]

What should we do with this issue @daveweisberg ?