Mai D D, Hallmann J, Reusch T, Osterhoff M, Düsterer S, Treusch R, Singer A, Beckers M, Gorniak T, Senkbeil T, Dronyak R, Gulden J, Yefanov O M, Al-Shemmary A, Rosenhahn A, Mancuso A P, Vartanyants I A, Salditt T
Institute for X-ray Physics, Georg-August-University Göttingen, Göttingen, Germany.
Opt Express. 2013 Jun 3;21(11):13005-17. doi: 10.1364/OE.21.013005.
The spatial coherence of free-electron laser radiation in the water window spectral range was studied, using the third harmonic (λ<(3rd) = 2.66 nm) of DESY's Free-electron LASer in Hamburg (FLASH). Coherent single pulse diffraction patterns of 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC) multilamellar lipid stacks have been recorded. The intensity histogram of the speckle pattern around the first lamellar Bragg peak, corresponding to the d = 5 nm periodicity of the stack, reveals an average number of transverse modes of M¯ = 3.0 of the 3rd harmonic. Using the lipid stack as a 'monochromator', pulse-to-pulse fluctuations in the third harmonic λ(3rd) have been determined to be 0.033 nm.
利用位于汉堡的德国电子同步加速器研究所的自由电子激光（FLASH）的三次谐波（λ<(3rd) = 2.66 nm），研究了水窗光谱范围内自由电子激光辐射的空间相干性。记录了1,2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）多层脂质堆叠的相干单脉冲衍射图案。对应于堆叠d = 5 nm周期的第一个层状布拉格峰周围散斑图案的强度直方图显示，三次谐波的横向模式平均数M¯ = 3.0。利用脂质堆叠作为“单色仪”，已确定三次谐波λ(3rd)的逐脉冲波动为0.033 nm。
