Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources.

Area of Science:

• Physics
• Materials Science
• Ion Source Technology

Background:

• High current density ion beams are crucial for various applications.
• Lithium alumino-silicate sources offer potential for efficient ion emission.
• Understanding operational limits and lifetime is essential for practical use.

Purpose of the Study:

• To investigate the performance and operational characteristics of lithium alumino-silicate ion sources.
• To determine the current density limits and lifetime of these ion sources.
• To identify factors influencing source longevity and beam emission.

Main Methods:

• Utilized lithium alumino-silicate ion sources with specific dimensions and coating thickness.
• Operated sources at approximately 1275 °C and varied extraction voltages.
• Conducted pulsed operation at 0.05 Hz with ~6 μs pulse lengths.
• Monitored current densities and source lifetime under different conditions.

Main Results:

• Achieved space-charge-limited beam current densities exceeding 1 mA/cm(2).
• Observed emission-limited behavior at higher voltages with J ≥ 1.5 mA/cm(2).
• Measured a source lifetime of approximately 40 hours under pulsed conditions.
• Found source lifetime independent of extracted beam charge due to neutral atom loss.
• Demonstrated increased lifetime with thicker alumino-silicate coatings and reduced temperature between pulses.

Conclusions:

• Lithium alumino-silicate ion sources can deliver high current densities suitable for demanding applications.
• Source lifetime is a critical parameter, extendable through material optimization and thermal management.
• Further research into optimizing coating and temperature profiles can enhance long-term operational stability.