TEMPEST Simulations of the Plasma Transport in a Single-Null Tokamak Geometry

Journal Article · Fri May 28 00:00:00 EDT 2010 · Nuclear Fusion

DOI:https://doi.org/10.1088/0029-5515/50/6/064003· OSTI ID:1237562

Bodi, K. ^[1]; Cohen, R. H. ^[2]; Krasheninnikov, S. ^[1]; Rognlien, T. D. ^[2]

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1. Univ. of California, San Diego, CA (United States)
2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

We present edge kinetic ion transport simulations of tokamak plasmas in magnetic divertor geometry using the fully nonlinear (full-f) continuum code TEMPEST. Besides neoclassical transport, a term for divergence of anomalous kinetic radial flux is added to mock up the effect of turbulent transport. In order to study the relative roles of neoclassical and anomalous transport, TEMPEST simulations were carried out for plasma transport and flow dynamics in a single-null tokamak geometry, including the pedestal region that extends across the separatrix into the scrape-off layer and private flux region. In a series of TEMPEST simulations were conducted to investigate the transition of midplane pedestal heat flux and flow from the neoclassical to the turbulent limit and the transition of divertor heat flux and flow from the kinetic to the fluid regime via an anomalous transport scan and a density scan. The TEMPEST simulation results demonstrate that turbulent transport (as modelled by large diffusion) plays a similar role to collisional decorrelation of particle orbits and that the large turbulent transport (large diffusion) leads to an apparent Maxwellianization of the particle distribution. Moreover, we show the transition of parallel heat flux and flow at the entrance to the divertor plates from the fluid to the kinetic regime. For an absorbing divertor plate boundary condition, a non-half-Maxwellian is found due to the balance between upstream radial anomalous transport and energetic ion endloss.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1237562
• Report Number(s): LLNL-JRNL-424563; TRN: US1600614
• Journal Information: Nuclear Fusion, Vol. 50, Issue 6; ISSN 0029-5515
• Publisher: IOP Science
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION