Ultrahigh-Resolution Imaging of Bio-Samples with Modern and Future Ultrabright X-Ray Sources: the Source and Method Requirements

Coherent x-rays promise breakthrough in imaging and especially time-resolved imaging, which is a critical technology for basic research, material- and bio-sciences. The key technique now is the Coherent Diffractive Imaging (CDI) and its variations. The achievable resolution is limited mainly by two factors: the available photon flux because large-angle diffraction efficiency is low, and the radiation damage which is especially severe for bio-samples. Thus, for bio-imaging with ultrahigh-resolution (i.e. better than several nanometers and ideally with atomic resolution), a powerful coherent x-ray source must provide a very large number of photons in a very short pulse so that single-shot exposure gives all necessary information before the sample is destroyed. Importantly, higher resolution requires shorter pulses as the acceptable displacement of the sample atoms gets smaller. This in turn requires larger x-ray pulse bandwidth, which at some point starts to contradict one of the main CDI requirements of very narrow bandwidth. I will analyze the performance of modern and future coherent x-ray sources (XFELs and laser-based compact sources including atomic harmonics and novel source based on x-ray emission from relativistic plasma singularities) and imaging methods and formulate requirements, in particular bandwidth requirements, that are necessary to achieve ultrahigh resolution. The work is supported by JSPS Kakenhi JP 26707031.The 1st QST International Symposium "Quantum Life Science