SOLPS simulations with electron kinetic effects

Zhao, Menglong; Chankin, A.; Coster, D.

doi:10.1088/1361-6587/aaf4ea

Cited by 6 publications

(7 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Non‐Maxwellian effects of electron distribution functions on the effective ionization rate coefficient S cr in self‐consistent KIPP‐SOLPS coupling simulations were investigated in ref. , where the cut‐off level max = 10 was found to provide good agreement between the rate coefficient S cr calculated from Equation (18) with Maxwellian electron distribution function f M and that taken from the ADAS database, as shown in Figure . The comparison between line radiation coefficient

{false\sum}_{k, j}^{j > k} Δ E_{j \to k} A_{italickj} α_{j}

calculated with max = 10 and f M and that from the ADAS database is also shown in Figure .…”

Section: Numerical Validation Of the Inelastic Operatormentioning

confidence: 57%

“…The first was elucidated in ref. , which showed that non‐Maxwellian tails had little influence on rates. This work is mainly focused on the second effect, which requires the inelastic collision operator in the kinetic code KIPP.…”

Section: Discussionmentioning

confidence: 99%

“…A previous study fully investigated the KIPP‐SOLPS coupling algorithm, and kinetic effects of parallel electron transport were presented in ref. . However, as described in Section 2, during Step (3) of the coupling algorithm, the plasma profiles in KIPP were maintained by the automatic particle and energy source terms: S p and S E , numerically implemented as the uniform particle and energy source schemes F S ( f ) and F E ( f ), defined in: F E ( f ) represents the process of uniform electron power input or subtraction, which converts one Maxwellian into another without changing the number of particles and momentum.…”

Section: Inelastic Collision Operatormentioning

confidence: 99%

“…As in ref. , atomic rate coefficients related to ionization and line radiation are calculated by Equations (24) and (25). However, in this work, the corresponding electron cooling radiation removal in KIPP is described by two numerical schemes:…”

Section: Simulationsmentioning

confidence: 99%

“…The KIPP‐SOLPS coupling algorithm enables one to treat electron parallel transport fully kinetically while still retaining all the physics that SOLPS has, which would be time consuming to capture using a kinetic code, and is accurately captured by the fluid code. In previous studies, the KIPP‐SOLPS coupling algorithm was extensively investigated. The atomic physics was treated in SOLPS code, and the corresponding electron cooling due to ionization, line radiation, and recombination‐bremsstrahlung radiation was included in KIPP by a uniform power removal scheme, as described in Section 2, which was, however, not realistic, especially for plasmas downstream near the target.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Implementation of an inelastic collision operator into KIPP‐SOLPS coupling and its effects on electron parallel transport in the scrape‐off layer plasmas

Zhao

Chankin

Coster

2019

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

This paper develops an inelastic collision operator for the Kinetic Code for Plasma Periphery (KIPP) code to investigate the kinetic effects of electron cooling due to inelastic collisions. It is fully tested based on the self-consistent KIPP-SOLPS coupling algorithm by being compared to the ADAS database. The collisional radiative rate coefficients from the ADAS database for deuterium atomic physics can be recovered using the inelastic collision operator with assuming Maxwellian electrons, which shows that the inelastic collision operator works well for various plasma conditions. Across a wide range of plasma conditions in the scrape-off layer, KIPP-SOLPS coupling simulation results with the implementation of an inelastic collision operator are not significantly different from results using a simpler uniform cooling scheme. The uniform scheme is thus recommended rather than including computationally intensive inelastic collision physics. KEYWORDSedge plasmas, fluid, inelastic collision operator, kinetic INTRODUCTIONPower exhaust is one of the critical issues of future fusion devices. Currently, two-dimensional (2D) fluid codes solving Braginskii-like equations [1] are utilized to investigate tokamak edge plasmas, like SOLPS, [2] EDGE2D, [3] and UEDGE. [4] However, the validity of the fluid model is often violated by electron parallel non-local transport [5][6][7] along magnetic field lines in the scrape-off layer. Non-Maxwellian tails of electron distribution functions due to the non-local transport greatly influence electron-related transport coefficients in fluid equations, which are obtained by assuming collisional plasmas. The Kinetic Code for Plasma Periphery (KIPP), [8][9][10][11] which is a continuum kinetic code solving the Vlasov-Fokker-Planck equation [12] with high accuracy of collision terms for electron parallel transport, was coupled with SOLPS based on an iterative coupling algorithm, [13] briefly described in Section 2. The KIPP-SOLPS coupling algorithm enables one to treat electron parallel transport fully kinetically while still retaining all the physics that SOLPS has, which would be time consuming to capture using a kinetic code, and is accurately captured by the fluid code. In previous studies, [13][14][15] the KIPP-SOLPS coupling algorithm was extensively investigated. The atomic physics was treated in SOLPS code, and the corresponding electron cooling due to ionization, line radiation, and recombination-bremsstrahlung radiation was included in KIPP by a uniform power removal scheme, as described in Section 2, which was, however, not realistic, especially for plasmas downstream near the target. Previous kinetic simulations [5,10,[16][17][18] showed that the electron conductive heat flux was found to be carried mostly by the so-called heat-carrying electrons (HCEs), which have a kinetic energy of ∼5.95T e . A reminder that the ionization threshold for deuterium neutrals is 13.6 eV, HCE could be mainly responsible for the deuterium ionization in low temperature regions,

show abstract

{false\sum}_{k, j}^{j > k} Δ E_{j \to k} A_{italickj} α_{j}

calculated with max = 10 and f M and that from the ADAS database is also shown in Figure .…”

Section: Numerical Validation Of the Inelastic Operatormentioning

confidence: 57%

Section: Discussionmentioning

confidence: 99%

Section: Inelastic Collision Operatormentioning

confidence: 99%

Section: Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Implementation of an inelastic collision operator into KIPP‐SOLPS coupling and its effects on electron parallel transport in the scrape‐off layer plasmas

Zhao

Chankin

Coster

2019

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

show abstract

Ion temperature anisotropy model with cross‐field drifts in the scrape‐off layer

Zhao

Rognlien

Järvinen

et al. 2022

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

An ion temperature anisotropy model including cross‐field drifts has been implemented in the 2D transport code UEDGE. Two ion temperature equations are solved in the model to give separate ion temperatures perpendicular and parallel to the magnetic field, which results in an additional mirror force for ion parallel transport and also leads to an additional curvature drift in the perpendicular direction. In our previous work, an ion temperature anisotropy model was implemented and applied to the full 2D version of UEDGE including recycled neutrals. The simulation results showed that the mirror force due to anisotropy reduces ion parallel flow velocity, however, the simulations were presented without cross‐field electric and magnetic drifts. Nevertheless, in present medium‐size tokamaks or future compact fusion devices, cross‐fields are important. In this work, the anisotropy model is extended to be compatible with the inclusion of cross‐field drifts. Preliminary results on comparison between the model solutions with and without cross‐field drifts are presented.

show abstract