Comparing N versus Ne as divertor radiators in ASDEX-upgrade and ITER

Induced tungsten melting events in the divertor of ASDEX Upgrade and their influence on plasma performance

Tungsten rods of 1×1×3mm were exposed at the outer divertor plate of ASDEX Upgrade using a manipulator system. Controlled melting of the W rod in H-mode discharges was induced by moving the outer strike point towards the W-rod position. Visible light emission of ejected W droplets was recorded by fast camera systems. The resulting increase of tungsten concentration in the confined plasma was co...

Divertor Requirements and Performance in ITER

Pedestal Studies at ASDEX Upgrade

The ASDEX Upgrade suite of edge pedestal diagnostics has been significantly improved. A new edge ion temperature and toroidal velocity diagnostic as well as a novel diagnostic for radial electric fields (Er) have been added. The application of integrated data analysis in a probabilistic framework contributes substantially to the quality of Er and electron density profiles. The equilibrium recon...

Divertor interferometer diagnostic for ITER

In the harsh environment of the divertor region in ITER, plasmas spanning a huge density range from 1019 to 1022 m−3 are anticipated making measurement of the electron density particularly challenging. For any reasonable wavelength choice, the total phase measured by a conventional two-color interferometer system is always 2 and therefore subject to fringe counting errors. This problem can be r...

Upgrade of the infrared camera diagnostics for the JET ITER-like wall divertor.

For the new ITER-like wall at JET, two new infrared diagnostics (KL9B, KL3B) have been installed. These diagnostics can operate between 3.5 and 5 μm and up to sampling frequencies of ∼20 kHz. KL9B and KL3B image the horizontal and vertical tiles of the divertor. The divertor tiles are tungsten coated carbon fiber composite except the central tile ...