Fast plasma discharge capillary design as a high power throughput soft x-ray emission source

Area of Science:

• Plasma Physics
• Atomic and Molecular Physics
• X-ray Science

Background:

• Compact plasma sources are crucial for advanced research and applications.
• Existing sources often require high energy or complex designs.
• Developing efficient, high-repetition-rate sources is a key challenge.

Purpose of the Study:

• To present experimental details and results of a novel compact plasma capillary source.
• To investigate the source's performance for extreme ultraviolet (EUV) and soft X-ray generation.
• To analyze the relationship between operational parameters, plasma characteristics, and source lifetime.

Main Methods:

• Utilized alumina capillaries (1.6/3.2 mm inner diameter, 21/36 mm length) with water as dielectric and coolant.
• Employed a low-inductance, nanosecond discharge system with ~0.5 J stored energy.
• Charged capacitor plates using an insulated-gate bipolar transistor (IGBT) in under 1 μs.
• Acquired characteristic argon spectra (30-300 Å) and temporally resolved X-ray energy fluence.
• Analyzed ablated wall material to assess capillary lifetime.

Main Results:

• Demonstrated efficient operation of the compact plasma capillary source.
• Obtained characteristic argon spectra and X-ray fluence, enabling material ablation assessment.
• Correlated electron beams, soft X-ray output, capillary geometry, and lifetime.
• Investigated the role of electron beams and plasma on-axis.

Conclusions:

• The developed source provides a viable, low-energy, high-repetition-rate option for EUV and soft X-ray research.
• Capillary geometry and operational parameters significantly influence source performance and lifetime.
• Understanding electron beam dynamics is crucial for optimizing soft X-ray output and source longevity.