Feasibility of photoexcitation imaging in soft x‐ray microscopy using the transition to π* orbits in biological molecules

Abstract

In the so‐called water‐window wavelength region, the photoexcitation cross section is found to be larger by two orders of magnitude than those for the photoionizations of atoms. Making use of these physical phenomena, a new imaging method for microscopy was studied. We have concluded that this method is useful for the measuring the molecules in DNA or RNA of wet biological cells. A sufficient contrast for microscopy measurements can be obtained by using the photoexcitation of the 1s‐orbital electron to π* orbits.