Extended fast-ion D-alpha diagnostic on DIII-D.

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Diagnostic Techniques

Background:

• The Fast-Ion Deuterium-Alpha (FIDA) diagnostic measures energetic ions in fusion plasmas.
• The initial FIDA system was installed on DIII-D in 2005.
• Energetic ions are crucial for understanding fusion plasma dynamics.

Purpose of the Study:

• To detail the upgrades and capabilities of the second-generation (2G) FIDA diagnostic on DIII-D.
• To highlight improvements in spatial coverage and fast-ion velocity space resolution.
• To present the enhanced measurement capabilities for fusion research.

Main Methods:

• Installation of the 2G FIDA system in 2009 with 11 active in-beam and 3 passive off-beam views.
• Utilizing fast f/1.8 optical components and 1.5 mm core fibers for enhanced light gathering.
• Employing spectrometers, CCD cameras, photomultiplier tubes, and fast digitizers for data acquisition.

Main Results:

• Expanded spatial coverage with 11 active and 3 passive views.
• Enhanced fast-ion velocity space coverage due to more tangential views.
• High-frequency (1 kHz and 1 MHz) data acquisition capabilities for transient phenomena.

Conclusions:

• The 2G FIDA system significantly improves the measurement of energetic ions in fusion plasmas.
• Enhanced diagnostics are vital for advancing fusion energy science.
• The upgraded FIDA diagnostic provides more comprehensive data for plasma physics studies.