Development of a digital integrator for the KSTAR device

Area of Science:

• Fusion energy research
• Plasma physics instrumentation
• Advanced digital signal processing

Background:

• Long pulse durations in fusion devices necessitate highly accurate magnetic diagnostics.
• Signal offsets in traditional integrators lead to significant output drift during extended experiments.
• Existing solutions, like lock-in amplifiers, face challenges with data processing time.

Purpose of the Study:

• To develop a real-time digital integrator for magnetic diagnostics in long-pulse fusion devices.
• To minimize signal drift and improve data processing speed.
• To create a compact and efficient integration system for Wendelstein 7-X (W7-X).

Main Methods:

• Implementation of a Field Programmable Gate Array (FPGA) within the digitizer for onboard data processing.
• Direct data transfer from the FPGA to reflective memory, bypassing external computers.
• Development of a compact system integrating the digitizer, FPGA, and memory in a Peripheral Component Interconnect (PCI) chassis.

Main Results:

• Achieved real-time data integration, significantly reducing processing time compared to previous methods.
• Successfully suppressed integrator output drift to a low level.
• Demonstrated a highly compact system design suitable for fusion device instrumentation.

Conclusions:

• The FPGA-based digital integrator offers a significant advancement for magnetic diagnostics in long-pulse fusion devices.
• Real-time processing and compact design address key limitations of previous integration systems.
• The developed system is well-suited for demanding applications like Wendelstein 7-X (W7-X).