High-fluence and high-gain multilayer focusing optics to enhance spatial resolution in femtosecond X-ray laser imaging

Abstract

With the emergence of X-ray free-electron lasers (XFELs), coherent diffractive imaging (CDI) has acquired a capability for single-particle imaging (SPI) of non-crystalline objects under non-cryogenic conditions. However, the single-shot spatial resolution is limited to ~5 nanometres primarily because of insufficient fluence. Here, we present a CDI technique whereby high resolution is achieved with very-high-fluence X-ray focusing using multilayer mirrors with nanometre precision. The optics can focus 4-keV XFEL down to 60 nm × 110 nm and realize a fluence of >3 × 105 J cm−2 pulse−1 or >4 × 1012 photons μm−2 pulse−1 with a tenfold increase in the total gain compared to conventional optics due to the high demagnification. Further, the imaging of fixed-target metallic nanoparticles in solution attained an unprecedented 2-nm resolution in single-XFEL-pulse exposure. These findings can further expand the capabilities of SPI to explore the relationships between dynamic structures and functions of native biomolecular complexes.

Investigation of structural and reflective characteristics of short-period Mo/B4C multilayer X-ray mirrors

“…X-ray multilayer mirrors (MLMs) are used in various fields of science and technology, such as solar astronomy, X-ray lithography, X-ray microscopy and spectroscopy (Martı ´nez- Galarce et al, 2013;Chkhalo & Salashchenko, 2013;Akhsakhalyan et al, 2017;Fogelqvist et al, 2017). One of the important practical applications of X-ray multilayer mirrors is monochromatization and nanofocusing systems at synchrotron radiation stations (Rashchenko et al, 2020;Morawe, 2019;Morawe et al, 2017;Sawhney et al, 2011;Chkhalo, Garakhin, Malyshev et al, 2022;Mimura et al, 2010;Yumoto et al, 2022;Koyama et al, 2022). The possibility of enabling the mirror to intercept as much of the synchrotron radiation beam as possible is one of the aspects that must be taken into account when developing reflective elements for such applications.…”

Effect of Annealing on Stress, Microstructure, and Interfaces of NiV/B4C Multilayers

“…Nanoscale multilayers are nanometer-thick films of different alternating materials stacked periodically on each other. The nanoscale multilayers have extensive applications in advanced imaging, spectroscopy, and monochromator systems in synchrotron radiation [1][2][3][4][5][6]. Short-period multilayer films are becoming increasingly required for monochromators of synchrotron radiation to meet the conditions of a large grazingincidence angle, higher working energy, and higher energy resolution.…”

Spectral-brightness optimization of an X-ray free-electron laser by machine-learning-based tuning

“…X-ray free-electron lasers (XFELs) based on a self-amplified spontaneous-emission scheme are X-ray sources that generate femtosecond hard X-ray laser pulses (Pellegrini et al, 2016). In combination with their high transverse coherence and high photon flux, XFELs provide novel experimental opportunities, such as damage-free protein crystallography (Schlichting, 2015;Hirata et al, 2014), coherent imaging of nanomaterials (Clark et al, 2013;Kimura et al, 2014;Yumoto et al, 2022), time-resolved analysis of chemical reactions (Kim et al, 2015(Kim et al, , 2020Katayama et al, 2019), generation and diagnostics of materials with high-energy densities (Vinko et al, 2012;Inoue et al, 2016Inoue et al, , 2021aInoue et al, , 2022a, and exploring nonlinear X-ray optical phenomena (Glover et al, 2012;Yoneda et al, 2015;Tamasaku et al, 2018;Inoue et al, 2021b).…”