A new technique for tokamak edge density measurement based on microwave interferometer.

A novel approach for density measurements at the edge of a hot plasma device is presented-Microwave Interferometer in the Limiter Shadow (MILS). The diagnostic technique is based on measuring the change in phase and power of a microwave beam passing tangentially through the edge plasma, perpendicular to the background magnetic field. The wave propagation involves varying combinations of refraction, phase change, and further interference of the beam fractions.

Development of the ion cyclotron emission diagnostic for the W7-X stellarator.

An ion cyclotron emission (ICE) diagnostic is prepared for installation into the W7-X stellarator, with the aim to be operated in the 2022 experimental campaign. The design is based on the successful ICE diagnostic on the ASDEX Upgrade tokamak. The new diagnostic consists of four B-dot probes, mounted about 72° toroidally away (one module) from the neutral beam injector, with an unobstructed plasma view.

Development of an experimental facility for the study of microparticle initiated radio frequency vacuum breakdown.

An ongoing objective in the ion cyclotron range of frequencies (ICRF) systems is the improvement of power coupling to the plasma. During the last decade, this goal has been mainly pursued through the study of the coupling resistance, either by optimizing the antenna layout or by tailoring the scrape-off layer profile with gas puffing. Another approach is to increase the voltage handling capability of the ICRF system, limited by breakdown in the launchers or in the transmission lines.

Ion temperature measurement techniques using fast sweeping retarding field analyzer (RFA) in strongly intermittent ASDEX Upgrade tokamak plasmas.

This manuscript presents a new method of interpreting the ion temperature (T) measurement with a retarding field analyzer (RFA) that accounts for the intermittent/turbulent nature of the scrape off layer (SOL) plasmas in tokamaks. Fast measurements and statistical methods are desirable for an adequate description of random fluctuations caused by such intermittent events as edge localized modes (ELMs) and blobs. We use a RFA that can sweep its current-voltage (I-V) characteristics with up to 10 kHz.