1 National Accelerator Laboratory , Stanford PULSE Institute , Menlo Park , CA 94025 , USA.
2 Department of Physics , Stanford University , Stanford , CA 94305 , USA.
Philos Trans A Math Phys Eng Sci. 2019 May 20;377(2145):20170477. doi: 10.1098/rsta.2017.0477.
Limits on the ability of time-resolved X-ray scattering (TRXS) to observe harmonic motion of amplitude, A and frequency, ω, about an equilibrium position, R, are considered. Experimental results from a TRXS experiment at the LINAC Coherent Light Source are compared to classical and quantum theories that demonstrate a fundamental limitation on the ability to observe the amplitude of motion. These comparisons demonstrate dual limits on the spatial resolution through Q and the temporal resolution through ω for observing the amplitude of motion. In the limit where ω ≈ ω, the smallest observable amplitude of motion is A = 2 π/ Q. In the limit where ω≥2 ω, A≤2 π/ Q is observable provided there are sufficient statistics. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
本文考虑了时间分辨 X 射线散射 (TRXS) 观察振幅 A 和频率 ω 围绕平衡位置 R 的谐振动的能力的限制。将 LINAC 相干光源的 TRXS 实验的实验结果与经典和量子理论进行了比较，这些理论证明了观察运动振幅的能力存在根本限制。这些比较表明，通过 Q 观察运动振幅的空间分辨率存在双重限制，通过 ω 观察运动振幅的时间分辨率存在双重限制。在 ω ≈ ω 的极限下，可观察到的最小运动振幅为 A = 2π/Q。在 ω≥2ω 的极限下，如果有足够的统计数据，则可观察到 A≤2π/Q。本文是“用 X 射线测量超快电子和结构动力学”主题特刊的一部分。
