Angular-divergence calculation for Experimental Advanced Superconducting Tokamak neutral beam injection ion source...

Area of Science:

• Plasma Physics
• Fusion Energy
• Beam Technology

Background:

• Neutral beam injection is critical for heating and sustaining plasma in fusion devices like the Experimental Advanced Superconducting Tokamak (EAST).
• Accurate determination of the ion source's angular divergence is essential for efficient beam delivery and plasma confinement.
• Traditional calorimetric methods provide valuable data but can be time-consuming and invasive.

Purpose of the Study:

• To develop and validate a secondary measurement technique for ion source angular divergence on the EAST tokamak.
• To improve the accuracy and enable real-time, non-perturbing divergence measurements.
• To compare results with established calorimetric methods and theoretical calculations.

Main Methods:

• Calorimetric measurements were performed to determine the angular divergence of the high-current ion source.
• A Doppler shift spectroscopy system was developed and implemented as a secondary diagnostic.
• A modified calculation model, adapted from W7AS neutral beam injectors, was used for slot-type accelerating grids.

Main Results:

• The Doppler shift spectroscopy system was successfully established for secondary divergence measurements.
• Preliminary spectroscopic results demonstrated comparability with calorimetrically determined values.
• The developed method offers potential for real-time, non-perturbing measurements, enhancing diagnostic capabilities.

Conclusions:

• Doppler shift spectroscopy provides a viable and complementary method for measuring ion source angular divergence.
• This technique enhances measurement accuracy and offers real-time monitoring capabilities for EAST's neutral beam injection system.
• The findings contribute to optimizing beam performance and plasma control in magnetic confinement fusion research.