The fast camera (Fastcam) imaging diagnostic systems on the DIII-D tokamak

Area of Science:

• Fusion energy research
• Plasma physics
• Tokamak diagnostics

Background:

• The DIII-D tokamak requires advanced diagnostic systems for effective plasma confinement studies.
• Previous camera systems faced limitations in resolution, calibration stability, and operational reliability.

Purpose of the Study:

• To detail the design and implementation of upgraded camera systems for the DIII-D tokamak.
• To enhance plasma imaging capabilities through improved optical designs and robust system integration.

Main Methods:

• Installation of two camera systems (90° and 225°) with distinct relay optics (fiber bundle vs. periscope).
• Implementation of neutron, X-ray, and magnetic shielding for enhanced reliability.
• Integration of an automated filter wheel for remote wavelength selection.
• Development of a software suite for automated data acquisition, storage, and remote operation.

Main Results:

• The periscope system offers calibration stability with 10 lp/mm resolution, while the fiber system provides high resolution (16 lp/mm) at the cost of calibration stability.
• Optimized shielding significantly reduces electronic interference and improves system reliability.
• Automated operations streamline data acquisition and analysis, reducing operator involvement.
• Spatial calibration accuracy of ≤2 cm achieved using wall features.

Conclusions:

• The upgraded camera systems enhance the DIII-D tokamak's diagnostic capabilities for plasma research.
• The system design balances resolution and calibration stability, offering flexibility for different diagnostic needs.
• Automated features and robust shielding contribute to increased operational reliability and data quality.