Abstract

A nonlinear gyrokinetic simulation, which incorporates both the reversed shear Alfvén eigenmode (RSAE) and the ion temperature gradient (ITG) turbulence, has been performed using the electromagnetic gyrokinetic Particle-In-Cell (PIC) code GEM. Strong nonlinear wave coupling and energy transfer between RSAE and ITG turbulence have been observed. Specific analyses show that the n = 4 Alfvén eigenmode primarily interacts with the ITG harmonics with long wavelength ($ n \text{\leqslant } 16 $). It is found that a background ITG turbulence can suppress the saturation level of RSAE and change the energetic particle transport. The frequency up-shift of RSAE and the frequency modulation on ITG components by RSAE are also observed. The impacts of the initial condition on the RSAE-ITG turbulence simulation are also discussed.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016028
• Keyword :

• Book : 605()
• Pub. Date : 2025
• Page : pp.155536
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112386
• Keyword :

Abstract

The liquid metal divertor (LMD) concept offers a promising solution to manage extreme heat loads in plasma devices. This study presents predictive simulations using the HeatLMD model for the COMPASS-U tokamak with a full toroidal liquid metal divertor, expected to achieve reactor-relevant divertor heat flux densities. We derive the scaling of the Li|Sn outflux over 7 assumed independent parameters, transferable to other tokamaks. Its transport to LCFS (via ERO2.0) and its radiation (via Aurora and FACIT) predicts acceptably low lithium concentration and negligible plasma cooling. However, for tin, the medium power scenario requires backside cooling beyond the capability of the ITER-like water-cooled divertor, though a temporary heat absorber can approximate this for a 1 s plasma pulse. For incident divertor power exceeding 2 MW and strike point Te < 10 eV, HeatLMD predicts significant tin plasma radiative disruption.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016014
• Keyword :

• Book : 604()
• Pub. Date : 2025
• Page : pp.155529
• Keyword :

• Book : 229()
• Pub. Date : 2025
• Page : pp.112406
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112352
• Keyword :

• Book : 227()
• Pub. Date : 2025
• Page : pp.112346
• Keyword :

• Book : 178()
• Pub. Date : 2025
• Page : pp.105503
• Keyword :

• Book : 431()
• Pub. Date : 2025
• Page : pp.113723
• Keyword :