Pfirsch-Schlüter Current

Overview

A similar SCENE scaling like that for the diamagnetic current is available for the Pfirsch-Schlüter current fraction $f_{\text{PS}}$. This is typically smaller than the diamagnetic current, but is negative.

There is no ability to input the diamagnetic and Pfirsch-Schlüter current directly. In this case, it is recommended to turn off these two scalings and to use the method of fixing the bootstrap current fraction.

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No Pfirsch-Schlüter current

To have it so that the Pfirsch-Schlüter current is not calculated you can set i_pfirsch_schluter_current = 0

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SCENE Fit:

This model can be used by setting: i_pfirsch_schluter_current = 2

This model is based off of 108 equilibria from SCENE. Overall the equilibria cover:

• $A$ = 1.6 to 3.2
• $\beta$ = 0.5% to 26%
• $\frac{P(0)}{\langle P \rangle}$ = 1.8 to 7.2
• $l_i$(2) = 0.21 to 1.0
• $\frac{q_{95}}{q(0)}$ = 0.9 to 16 (i.e. deeply hollow current to very peaked)

This fit is derived from the same dataset used to derive the diamagnetic current fraction for i_diamagnetic_current = 2

$$f_{\text{PS}} = -0.09 \beta$$