Sub-THz Characterization of Technical Surfaces for Particle Accelerator Vacuum Chambers

Area of Science:

• Materials Science
• Particle Accelerator Technology
• Electromagnetism

Background:

• Coatings in particle accelerator vacuum chambers are vital for pumping and mitigating electron cloud effects.
• Coating-induced surface impedance changes can limit accelerator performance, energy, and current.
• Understanding material response in the very-high-frequency (VHF) range is critical for next-generation accelerators.

Purpose of the Study:

• To present a novel technique for characterizing the sub-terahertz (sub-THz) electromagnetic response of coating materials.
• To evaluate the electromagnetic properties of technical surfaces used in accelerators under realistic conditions.
• To provide insights into material behavior in the sub-THz frequency range for optimizing accelerator performance.

Main Methods:

• A waveguide-based method was developed to measure pulsed signals transmitted through coated material samples.
• The technique probes the sub-THz response of deposited materials on a substrate.
• Experimental data from three Non-Evaporable Getter (NEG) coating samples prepared at CERN were analyzed.

Main Results:

• The study successfully demonstrated a technique to probe the sub-THz electromagnetic properties of accelerator coatings.
• Experimental data from NEG coatings provided valuable insights into their behavior in the sub-THz range.
• The methodology allows for comprehensive exploration of electromagnetic properties of technical surfaces.

Conclusions:

• The developed technique is essential for characterizing coating materials for advanced particle accelerators.
• Findings contribute to a deeper understanding of coating-accelerator structure interactions.
• The research aims to optimize performance and efficiency in particle acceleration technologies.