Here we aim at investigating the interaction of high-energy ion beams with cells on a sub-cellular scale. The corresponding changes in electron density, chemical ordering and ionization traces after ion beam irradiation can be studied on hydrated cells with high spatial resolution and elemental specificity by soft-X-ray spectro-microscopy in the “water window” (between 280 and 530 eV). In the first phase of the project we plan to develop and commission a Fresnel-zone-plate-based soft-X-ray scanning transmission microscope (STXM), using coherent soft-X-ray illumination from femtosecond laser driven high harmonic radiation. The optimization of the source will be performed in close collaboration with MAP researchers from Areas A.3 and B.1.
First proof-of-principle experiments have already been performed on dry diatoms (silica algae) showing sub-200 nm resolution and good image contrast with current HHG sources. Spectroscopic dual-wavelength imaging for elemental resolution and possible in-coupling and synchronization to a laser-driven ion beam source for imaging of ion beam irradiated samples are planned for the future. The coherent STXM setup will also provide a versatile test bed for Coherent Diffractive Imaging (in collaboration with Janos Hajdu, Laboratory of Molecular Biophysics, Uppsala University), where experimental aspects of (nanocrystalline) sample delivery, sample orientation, illumination coherence etc. can be studied on a laboratory scale prior to large-scale XFEL experiments. The project is linked to projects in C.3 on “Cellular and molecular radiation biology of laser-driven particle therapy” (C.3.3) and “Bio-medical aspects of laser-driven particle therapy” (C.3.4).