1D model of SOL with self consistent calculation of non-coronal radiation and applications to shallow field line angles

Abstract A 1D model of the scrape off layer is created with a physics based calculation of the impurity radiation and the inclusion of the perpendicular heat flux <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>q</mml:mi> <mml:mi mathvariant="normal">⊥</mml:mi> </mml:msub> </mml:mrow> </mml:math> compared to previous 1D models. The calculation of the impurity radiation includes the addition of a model using parallel and perpendicular motion to calculate the impurity confinement time τ and the inclusion of charge exchange between neutral hydrogen and impurity ions. Reasonable agreement is found between the model and the 2D fluid code SOLPS-ITER. Additionally, an improvement is shown over the constant τ used in previous works. The model is used to examine the effects of shallow field line angles at ITER levels of parallel heat flux ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>q</mml:mi> <mml:mrow> <mml:mo stretchy="false">|</mml:mo> <mml:mo stretchy="false">|</mml:mo> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> ). A large increase in radiation results in an increase in the upstream parallel heat flux which can still be in detachment at shallow field line angles for both <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>q</mml:mi> <mml:mi mathvariant="normal">⊥</mml:mi> </mml:msub> </mml:mrow> </mml:math> and the calculated τ for traditional impurities (argon and nitrogen) as well as boron. The physics behind this increase in radiation at shallow field line angles is shown to be a decrease in τ and a change in the temperature profile with the inclusion of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>q</mml:mi> <mml:mi mathvariant="normal">⊥</mml:mi> </mml:msub> </mml:mrow> </mml:math> .