| 日時: |
2012-07-04 10:00 - 11:30 |
| 場所: |
３号館セミナーホール |
| 会議名: |
Sub-Angstrom Stabilization of X-Ray Free Electron Laser Oscillator and Nuclear Resonance Metrology |
| 連絡先: |
hiroshi.kawata kek.jp |
| 講演者: |
Dr. Kwang-Je Kim (シカゴ大学) |
| 講演言語: |
英語 |
| アブストラクト: |
" Sub-Angstrom Stabilization of an X-ray Free Electron laser Oscillator and Nuclear Resonance Metrology"
A distinguishing feature of an x-ray free-electron laser oscillator (XFEL-O) is the full coherence of the hard x-pulses it generates, in particular the long temporal coherence length of 1 ps, four orders of magnitudes longer than that of SASE. Noting that the spectrum of an XFEL-O output has a comb structure as in a mode-locked laser, a far more drastic increase in the temporal coherence length is in principle feasible in a scheme where the cavity roundtrip path length is stabilized to the sub-Å level by locking one of the comb lines to the narrow resonance line of 57Fe nuclei. The standing-wave pattern formed by the stabilized XFEL-O output can be measured by another 57Fe sample over about one meter of optically predetermined length, thus improving accuracy of the 57Fe resonance wavelength determination by about four orders of magnitudes. The technique can be refined for other, narrower resonances such as 181Ta, opening up precision x-ray metrology for, e.g., experiment al quan tum gravity, matter-wave interferometry of mesoscopic particles, etc. |
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