Thermal desorption mass spectrometer for mass metrology

Area of Science:

• Surface science
• Analytical chemistry
• Metrology

Background:

• Mass standards require precise surface characterization.
• Understanding surface reactivity is key to maintaining metrological stability.
• Current methods may not fully capture surface contamination dynamics.

Purpose of the Study:

• To introduce a novel device for studying physisorbed elements on polished surfaces.
• To investigate the surface reactivity of mass standards.
• To correlate surface properties with storage, cleaning, and polishing.

Main Methods:

• Development of a device for analyzing polished surfaces (diameter ⩽56 mm).
• Utilizing thermal desorption mass spectrometry (TDMS) under vacuum.
• Heating the surface to desorb physisorbed molecules for mass analysis.

Main Results:

• Demonstrated application to current and future mass standards.
• Provided insights into surface reactivity influenced by environmental and processing factors.
• Showcased surface contamination analysis on pure iridium post-cleaning.

Conclusions:

• The developed device is effective for characterizing mass standard surfaces.
• Surface reactivity is demonstrably linked to storage, cleaning, and polishing.
• TDMS offers a valuable tool for optimizing mass standard maintenance and development.