Recent progress of the HCN interferometer on J-TEXT tokamak

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Interferometry Techniques

Background:

• Accurate measurement of plasma electron density is crucial for understanding and controlling fusion plasmas.
• The J-TEXT tokamak requires advanced diagnostics for detailed plasma behavior analysis.
• Far-infrared laser interferometry offers non-invasive methods for density diagnostics.

Purpose of the Study:

• To develop and implement a multichannel far-infrared HCN laser interferometer for electron density measurements in the J-TEXT tokamak.
• To evaluate the system's capability in providing high-resolution data for particle transport studies.
• To enhance the diagnostic's performance through optical configuration upgrades.

Main Methods:

• Development of a seven-chord HCN laser interferometer system.
• Achieving a temporal resolution of 0.1 ms and spatial chord spacing of 7 cm.
• Conducting density modulation experiments to assess diagnostic capabilities.
• Implementing an optical configuration upgrade to improve phase resolution.

Main Results:

• Successful initial operation of the seven-chord interferometer system.
• Demonstration of the system's ability to capture density perturbation amplitude and phase variations.
• Evidence that precise measurements yield information on particle transport.
• Identification of areas for improvement in phase resolution.

Conclusions:

• The developed multichannel HCN laser interferometer is a valuable tool for J-TEXT tokamak plasma diagnostics.
• The system enables detailed studies of particle transport through precise electron density measurements.
• Ongoing upgrades aim to further enhance the diagnostic's resolution and utility in fusion research.