Neutral beam dump with cathodic arc titanium gettering.

Area of Science:

• Plasma Physics
• Fusion Energy Engineering
• Materials Science

Background:

• Incomplete neutral beam capture degrades plasma performance in neutral beam-driven fusion devices.
• Beam dumps must manage high particle loads and prevent impurity release from recycled particles.
• Titanium arc gettering offers high evaporation rates and fast response for clean film deposition.

Purpose of the Study:

• To develop and evaluate a compact neutral beam dump using titanium arc gettering.
• To mitigate shine-through neutral beam recycling in a field-reversed configuration (FRC) plasma.
• To improve vacuum conditions and plasma performance in fusion devices.

Main Methods:

• Developed a compact neutral beam dump with an improved titanium arc evaporator design.
• Tested the beam dump in a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams.
• Measured the beam recycling coefficient under high particle flux densities.

Main Results:

• The developed beam dump effectively handles large pulsed gas loads with high sorption capacity.
• Achieved a beam recycling coefficient of approximately 0.7 at a flux density of 5 × 10^17 H/(cm^2 s) for 3-10 ms.
• Demonstrated significant reduction in shine-through neutral beam recycling.

Conclusions:

• The compact titanium arc gettering beam dump is robust, reliable, and efficient.
• This technology significantly reduces neutral beam recycling, enhancing vacuum conditions.
• The improved beam dump contributes to better plasma performance in neutral beam-driven machines.