Sweet R M, Singer P T, Smalås A
Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Acta Crystallogr D Biol Crystallogr. 1993 Mar 1;49(Pt 2):305-7. doi: 10.1107/S0907444992012095.
The white-beam Laue-diffraction method is a useful tool for rapid measurement of crystallographic intensities with synchrotron radiation. Considerations of the signal-to-noise ratio to be expected from scattering of X-rays within a limited wavelength range suggest that it will pay to limit that range to something like an octave. This rule-of-thumb has the added advantage that there will be significantly fewer diffraction spots that are overlapping harmonics of one another. To maximize the number of reflections recorded in a single stationary-crystal exposure, one should choose this octave of wavelengths in a region where the curvature of the Ewald sphere is greatest, that is at the longest wavelength allowable after other considerations are taken into account.
白光劳厄衍射法是利用同步辐射快速测量晶体学强度的一种有用工具。考虑到在有限波长范围内X射线散射预期的信噪比，将该范围限制在大约一个倍频程左右是值得的。这条经验法则还有一个额外的优点，即相互重叠的谐波衍射斑点会明显减少。为了在单次固定晶体曝光中记录到最多的反射，应在埃瓦尔德球曲率最大的区域选择这个波长倍频程，即在考虑其他因素后允许的最长波长处。
