Long-time measurements of line-integrated plasma electron density using a two-color homodyne optical fiber interferometer.

A two-color homodyne Mach-Zehnder (M-Z) optical fiber interferometer with wavelengths of 1.55 and 1.31 µm was developed for long-time measurement of line-integrated plasma electron density.

Measurement of density profile and fluctuations using a multi-channel terahertz solid-state interferometer system on Keda Torus eXperiment (KTX).

A five-chord interferometer based on terahertz solid state sources has been successfully installed on the Keda Torus eXperiment (KTX), a reversed field pinch machine. The optical design has been carefully optimized for the uniform distribution of beam light to fully use the limited power source (∼2 mW). By setting the telescopic mirror unit, the beam waist is located in the center of the vacuum vessel and its diameter is in the range of the Rayleigh length.

Optical fiber interferometer application for high electron density measurements on compact torus plasmas.

An optical fiber Mach-Zehnder interferometer at a wavelength of 1.55 µm has been developed for measurements of high electron density on compact torus (CT) plasmas with a high time resolution of 0.1 µs and high phase resolution of 6.

A parametric method for correcting polluted plasma current signal and its application on Keda Torus eXperiment.

We have developed a parametric method for eliminating the background component of the plasma current, which is measured by a Rogowski coil and polluted by the toroidal magnetic field in the vacuum vessel of the Keda Torus eXperiment (KTX) reversed field pinch (RFP) device. The method considers the toroidal magnetic field windings, the KTX vacuum chamber, and the Rogowski coil as a linear time-invariant system; in this case, a constant frequency response function characterizes the system. Using this response function, the current component caused by pollution from the toroidal magnetic field can be predicted exactly for an arbitrary input current to the toroidal magnetic field windings.