Element-specific observation of ultrafast dynamics in light-induced photocatalysis using X-ray free-electron lasers

2014 Fiscal Year Final Research Report

• Project/Area Number: 25790093
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: Japan Synchrotron Radiation Research Institute
• Principal Investigator: KATAYAMA Tetsuo 公益財団法人高輝度光科学研究センター, XFEL利用研究推進室, 研究員 (90648073)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: X線自由電子レーザー / 超高速時間分解計測 / X線吸収分光

Outline of Final Research Achievements

I have developed two experimental schemes, dispersive and fluorescence yield methods, for time resolved x-ray absorption spectroscopy. To confirm their performance to trace the ultrafast intermediates in light-induced reactions, time-resolved measurements were performed for iron ferrioxalate solution, combined with synchronized optical laser. I successfully observed the bond dissociation, change of electronic structures with sub-picosecond time resolution.
Furthermore, I have tried to improve the time resolution limited by the relative timing jitter between XFEL and optical laser. The high-intensity x-ray irradiation induces the fast increase of electronic temperature and transmission decrease inside the semiconductor (GaAs) wafer. Combined with spatial decoding, the timing jitter was measured. I successfully achieved ~10 femtoseconds accuracy in the measurement, which improves the time resolution drastically.

Free Research Field

X線分光