- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Stripline beam position monitor for X-ray free electron laser of Pohang Accelerator Laboratory
摘要： Beam position monitors (BPMs) are important instruments even in the case of an X-ray free-electron laser (XFEL). Pohang Accelerator Laboratory (PAL) finished the construction of an XFEL (PAL-XFEL) in 2015, and new stripline BPMs were installed in PAL-XFEL. New BPMs were designed to have a strong signal and a high resolution. In addition, the impedance matching was considered to reduce a signal reflection. These features of the BPM design were confirmed with a simulation study as well. Fabricated BPMs were tested by using a wire test stand. Two-dimensional position errors and offsets were measured to select best BPMs for PAL-XFEL. Finally, a real beam test was tried to check the BPM performance and a better resolution than the requirement was obtained.
关键词： stripline BPM,X-ray free-electron laser,Beam position monitors,impedance matching,PAL-XFEL
更新于2025-09-11 14:15:04
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Establishing a Canadian free-electron laser research program
摘要： The Canadian Scienti?c and Engineering community recognizes the need to establish a free-electron laser (FEL)-based program of research. This program should focus on applications in chemistry, biology, physics, materials science, nanotechnology, earth and environmental science, and medicine, and it should include developmental engineering and machine physics. The expert community concludes that the unique capabilities of FELs can offer new and remarkable insights across a diverse range of scienti?c ?elds. A strategic approach to develop world-class infrared FEL science in Canada is proposed.
关键词： infrared,FEL,research program,Canada,free-electron laser
更新于2025-09-11 14:15:04
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Time-resolved photoelectron angular distributions from nonadiabatically aligned CO <sub/>2</sub> molecules with SX-FEL at SACLA
摘要： We performed time-resolved photoelectron spectroscopy of valence orbitals of aligned CO2 molecules using the femtosecond soft x-ray free-electron laser and the synchronized near-infrared laser. By properly ordering the individual single-shot ion images, we successfully obtained the photoelectron angular distributions (PADs) of the CO2 molecules aligned in the laboratory frame (LF). The simulations using the dipole matrix elements due to the time dependent density functional theory calculations well reproduce the experimental PADs by considering the axis distributions of the molecules. The simulations further suggest that, when the degrees of alignment can be increased up to ácos2 q? > 0.8, the molecular geometries during photochemical reactions can be extracted from the measured LFPADs once the accurate matrix elements are given by the calculations.
关键词： free electron laser,photoelectron spectroscopy,photoelectron angular distribution,aligned molecules
更新于2025-09-09 09:28:46