High-performance ELM-free semi-detached scenario

It would be good to include models based on up to date experimental results. One option is:
High-performance ELM-free semi-detached scenario sustained at high-current in JET DTE3 (synopsis)
(Slides)
The provisional name for this scenario is Seeded Enhanced Pedestal (SEP).

• A Ne-seeded plasma in D-T with partially detached divertor has been achieved in stationary conditions without ELMs:
  JPN#104600
  q95=2.7, H98(y,2) = 0.85, fgw=0.75, βN ∼2.1, $C_{Ne}\approx 1.8$%

• In D-D and D-T, increasing Ne seeding enables a gradual and smooth transition to high confinement (H98(y,2) > 0.85, frad>0.8) and ELM-free regime.

• From the dataset obtained, the conditions to reach high confinement with no ELMs are a high enough power, Psep/PLH≥1.25, and a separatrix density ne,sep ~2e19m-3.

• When the plasma enters this regime and the Ne content is further increased, a smooth H-L transition with no hard re-attachment is observed. This is an additional benefit of this regime.

• Unsurprisingly, with a partially detached divertor and no ELMs, the W erosion is negligible, leading to a core W content reduction ($C_W<0.6\times 10^{-5}$). This is an another benefit.

There is an issue: this plasma has an X-point radiator, but it is not clear from the bolometric tomogram what fraction of the total radiation this represents.
Pulse info: https://data.jet.uk/dashboard/pulses/104600/overview

How do we scale these results to the DEMO regime?
Carine (who is the Topic Coordinator) tells me that Geert Verdolaege is developing a new confinement scaling for radiative pulses.

1. We need definitions of the parameters quoted, in terms of unambiguous quantities.
2. We can set a default 25% margin for the LH threshold: Psep/PLH≥1.25
3. We can set a default value of H98 (once it is properly defined) as 0.9.
4. We need to know $f_{rad}$ for the JET pulses.
5. We need to make up a scaling for the maximum allowed separatrix density $n_{e,sep}$. Admittedly, PROCESS doesn't do very much with $n_{e,sep}$, so this may not be a big problem.
6. We need to make up a scaling for the maximum allowed pedestal density $n_{e,ped}$.
7. For extrapolation, should we set a fixed neon concentration, or a fixed value of $f_{rad}$?

As an example only, the ITPA database uses these definitions DB5.4.3 or DB5.2.3:

90. PRAD
    Description: Total radiated power
    Note this does not specify whether PRAD only includes the power from inside the separatrix.

91. WTH
    Estimated thermal plasma energy content

92. PL
    Estimated loss power not corrected for charge exchange and unconfined orbit losses
    JET: PL=POHM+PNBI+PICRH−DWDIA
    Note that alpha power is omitted!

93. PLTH
    Estimated loss power corrected for charge exchange and unconfined orbit losses
    Calculated as PLTH=PL−PFLOSS

94. TAUTH
    Estimated thermal energy confinement time
    Calculated as TAUTH=WTH/PLTH

95. HIPB98Y2
    Confinement enhancement factor w.r.t. IPB98(y,2)
    Calculated as HIPB98Y2=TAUTH∗TAUC92 / IPB98(y,2),
    where IPB98(y,2) is the prediction by the IPB98(y,2) scaling law [IPB99]
    Note that the database does not give the definition of IPB98, only a reference to the paper.

96. TAUC92
    Description: Correction factor for thermal confinement time TAUTH
    (See list of variables for details)

Start by reviewing the linked experimental synopsis, slides, JET pulse overview, and the cited ITPA database definitions. The issue does not name implementation files or tests; first determine how PROCESS represents confinement, radiation, power, and density limits. Done requires unambiguous parameter definitions and agreed scaling rules for the SEP scenario and DEMO extrapolation.