[Plenary session] Special lecture/Award ceremony/Closing session

[2Aa01(基調講演、2023学会賞)] Study of Surface Dynamics by Coincidence Spectroscopy and Development of Novel Non-Evaporative Getters Based on Surface Science

*Kazuhiko Mase^1,2 (1. High Energy Accelerator Research Organization (KEK), 2. SOKENDAI)

When a surface is irradiated with soft X-rays, core ionization, Auger processes, and ion desorption occur in 0.1 ps. To elucidate these dynamics, we have developed electron – ion coincidence spectroscopy, and clarified the H⁺ desorption mechanism induced by 4a₁ ← O 1s resonant excitation of condensed H₂O. We have also developed Si-L₂₃VV-Si-2p Auger-electron – photoelectron coincidence spectroscopy (APECS) and identified topmost-surface Si-2p photoelectron components of Si(100)-2×1, and investigated local valence electronic structures of Si(111)-7×7. Around 2016 we moved to nonevaporable getter (NEG) research based on surface science, and have developed a new NEG, Pd overcoated on Ti thin film with a purity higher than 99.95% (oxygen-free Pd/Ti), which pumps H₂ and CO after baking at 133 °C for 12 hours. Then we developed a zero-length conflat fin-type nonevaporable getter (NEG) pump using oxygen-free Pd/Ti deposition. The oxygen-free Pd/Ti NEG pumps have been commercialized in 2018.