Extended Data Fig. 2: Coaxial detector tip.

a, Transmission X-ray microscopy image of a detector tip shows several materials composing the tip. Scanning electron microscopy image of a detector tip before (b) and after (c) incision. Here the PtIr conducting core is used to collect electrons, whereas the SiO₂ insulating layer prevents collection of ejected electrons from the sample by the side wall of the tip. The outer Au conducting layer is to protect from the charging effect^34,35.