Fine positioning of a poloidal probe array

Area of Science:

• Plasma physics
• Nonlinear dynamics
• Astrophysical fluid dynamics

Background:

• Plasma turbulence is a complex nonlinear phenomenon crucial for understanding space and astrophysical systems.
• Accurate multipoint detection is vital for characterizing turbulence properties like nonlinear mode couplings.
• Existing diagnostic methods face challenges in precisely measuring wave number spectra due to instrumental limitations.

Purpose of the Study:

• To present a novel 64-channel poloidal probe array for detailed investigation of plasma turbulence.
• To study nonlinear mode couplings in the poloidal wave number and frequency domain.
• To analyze and mitigate the impact of probe tip misalignments on wave number measurements.

Main Methods:

• Fabrication of a 64-channel poloidal probe array surrounding the LMD-U linear cylindrical plasma device.
• Implementation of adjustable probe positions to correct for tip misalignments.
• Analysis of the effects of probe misalignments on the measured wave number spectra.

Main Results:

• The developed probe array enables high-resolution multipoint detection of plasma turbulence.
• Misalignments in probe tips were identified as a source of spurious modes, distorting wave number measurements.
• The study quantifies the impact of these misalignments on the accuracy of turbulence analysis.

Conclusions:

• The 64-channel poloidal probe array is a valuable tool for studying plasma turbulence and nonlinear couplings.
• Addressing probe alignment is critical for accurate wave number measurements in plasma diagnostics.
• This work provides a method for improving the reliability of turbulence data obtained from probe arrays.