A 60-GHz interferometer with a local oscillator integrated antenna array for divertor simulation experiments on GAMMA...

Area of Science:

• Plasma Physics
• Microwave Diagnostics
• Fusion Energy Research

Background:

• Conventional microwave diagnostics (interferometry, reflectometry, electron cyclotron emission) rely on complex LO signal distribution via optics.
• Existing systems often require expensive high-frequency sources (e.g., 60-GHz) and waveguide transmission lines.

Purpose of the Study:

• To introduce a novel 60-GHz interferometer system featuring a local oscillator integrated antenna array (LIA).
• To simplify and improve the uniformity of local oscillator (LO) signal supply to receiver arrays in microwave diagnostics.

Main Methods:

• Development of an eight-channel receiver array (LIA) incorporating a frequency quadrupler integrated circuit for each channel.
• Utilizing a single 15-GHz LO source and coaxial cable transmission for LO signal distribution.
• Application of the new interferometer system to measure electron line-averaged density in the D-module of the GAMMA 10/PDX tandem mirror device.

Main Results:

• The LIA enables a simplified and uniform LO supply to the receiver array.
• Eliminates the need for expensive 60-GHz sources, LO optics, and waveguide transmission lines.
• Successfully applied to measure electron density in a fusion plasma experiment.

Conclusions:

• The local oscillator integrated antenna array (LIA) offers a cost-effective and efficient solution for LO signal distribution in microwave diagnostics.
• This innovation facilitates advanced plasma measurements in devices like the GAMMA 10/PDX tandem mirror.
• The LIA system represents a significant advancement in the design of microwave diagnostic systems for fusion research.