Heat and particle transport of SOL and divertor plasmas in the W shaped divertor on JT-60U

The geometry effects of the W shaped divertor on the divertor plasma were investigated quantitatively. The ion flux was increased near the divertor strike point, which is effective for reducing the local electron temperature and decreasing the onset e of divertor detachment. The plasma profile and parallel plasma flow in the scrape-off layer were systematically measured using reciprocating Mach probes installed at the midplane and the divertor X point. For the ion ∇B drift direction towards the divertor, `flow reversal' was observed at the midplane. A quantitative evaluation of the parallel plasma flow suggesting that the flow is produced in a torus to keep the pressure constant along the field lines was consistent with the measurements.