자료유형 | 학위논문 |
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서명/저자사항 | Micro-Focused MHz Pink Beam for Time-resolved X-ray Emission Spectroscopy. |
개인저자 | Tu, Ming-Feng. |
단체저자명 | Northwestern University. Physics and Astronomy. |
발행사항 | [S.l.]: Northwestern University., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 116 p. |
기본자료 저록 | Dissertations Abstracts International 81-03B. Dissertation Abstract International |
ISBN | 9781085642026 |
학위논문주기 | Thesis (Ph.D.)--Northwestern University, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-03, Section: B.
Advisor: Bostedt, Christoph |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | Valence-to-core (vtc) x-ray emission spectra (XES) provides direct information on occupied valence orbitals and is sensitive to chemical environment. Combining with element specificity and high penetration of hard x-rays, it is emerging as an information-rich technique and its applications have been demonstrated in research fields, such as catalysis and metalloenzymes. However, the vtc feature is typically two orders of magnitude weaker than Kalpha emission lines, making it hard to collect, especially for transient species. To overcome this disadvantage, pink beam excitation capability was demonstrated recently at Sector 7 of the Advanced Photon Source. A water-cooled mirror rejects high harmonics from the undulator, and beryllium compound refractive lenses (CRL) focus the reflected fundamental beam (pink beam) to a 40 x 12 microns elliptical spot (~1015 photons/second) at the sample target that matches the laser spot size used for photoexcitation. In combination with an ultrafast laser, the focused pink beam was utilized to probe the photoexcited spin crossover (SCO) process of [FeII(bpy)3]2+ in a liquid jet with a laser-pump/x-ray-probe scheme. The results successfully demonstrated the application of this pink beam capability for ultrafast charge transfer dynamics in solvated molecules. |
일반주제명 | Physics. |
언어 | 영어 |
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