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Impact of Fast-Ion Transport on Thermal Profiles in the DIII-D qmin>2 Steady-State Tokamak Scenario

POSTER

Abstract

The viability of steady-state scenarios in ITER and future reactors relies on effective heating by energetic particles (EPs) to achieve high beta and bootstrap current. To clarify the impact of EP transport on thermal profiles, the TGLF-EP+Alpha critical-gradient model is used to calculate Alfvén Eigenmode (AE)-induced EP transport. Thermal ion and electron profiles are predicted using TGYRO with TGLF using the experimental density, rotation, and TRANSP power and particle sources. In the current ramp where AE-induced transport reduces core EP density by 50%, the T_i profile is overpredicted by up to 25% when input from classical TRANSP (no mode-induced transport) is used. However, the profile is accurately reproduced and the neutron rate matches measurements within 12% using TRANSP with EP diffusion calculated by TGLF-EP+Alpha. Thus, thermal profiles are accurately predicted by simply accounting for AE-induced changes to power fluxes and using thermal density consistent with transported EP density (i.e. does not include EP interaction with microturbulence). This result shows promise for applying TGLF-EP in integrated modeling for scenario development and reactor scoping studies.

Presenters

  • Cami S Collins

    Oak Ridge National Laboratory, General Atomics - San Diego, Oak Ridge National Lab

Authors

  • Cami S Collins

    Oak Ridge National Laboratory, General Atomics - San Diego, Oak Ridge National Lab

  • Eric M Bass

    University of California, San Diego

  • Christopher T Holcomb

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, LLNL, Lawrence Livermore National Lab