Tangential soft-x ray imaging for three-dimensional structural studies in a reversed field pinch

Area of Science:

• Plasma physics
• Fusion energy research
• Magnetic confinement fusion

Background:

• Understanding the 3D structure of magnetic surfaces is crucial for controlling plasma behavior in fusion devices.
• Previous methods for magnetic surface analysis had limitations in spatial resolution and dimensionality.

Purpose of the Study:

• To develop and validate a tangential soft-X-ray (SXR) imaging diagnostic for deducing the 3D magnetic surface structure.
• To investigate the internal magnetic topology of the REversed field pinch of Low-Aspect-ratio eXperiment (RELAX) device.

Main Methods:

• Development of an SXR imaging system comprising a microchannel plate (MCP), fluorescent plate, and intensified CCD camera.
• Acquisition of tangential SXR images from the RELAX machine.
• Comparison of experimental SXR images with 2D SXR images calculated using a single island model.

Main Results:

• The developed SXR imaging system successfully captured experimental SXR images.
• Numerical calculations using a single island model reproduced major characteristics of the experimental SXR images.
• The results suggest the presence of a helical hot core within the RELAX plasma.

Conclusions:

• The tangential SXR imaging system is a valuable tool for 3D magnetic structure studies in fusion devices.
• Integration with vertical imaging systems and advanced numerical modeling will enhance 3D structural analysis capabilities.
• The findings provide insights into plasma confinement and stability in reversed field pinch devices.