A proposed nuclear nanoprobe with Angstrom resolution

An idea is presented for an entirely new point-projection nuclear microscope that theoretically would have sub-nanometer resolution, approaching one Angstrom. The concept involves using a Kalbitzer super tip as a source of low energy (∼100eV) He or H ions that would be transmitted through a molecular sample (e.g. buckyball, carbon nanotube, graphene sheet, DNA molecule, etc.) placed very near the tip (∼1–100nm), and then projected onto a microchannel plate (MCP) screen placed ∼1m from the tip. Small angle scattering of the incident ions with atoms in the sample result in the development of shadow cones with an increase in scattered ion intensity at the critical cone angle. The enhanced intensity patterns formed at multiple intersections of cone perimeters are called “threads”. The shadow cones and threads are projected onto a suitable low-energy ion position sensitive detector to create a “shadow or thread image” of the sample. Such point-projection microscopes have no aberrations that affect the image, and the magnification would be of the order 1m/10nm, or 1.E8! The feasibility of this scheme is currently being studied theoretically using a deterministic atomic scattering model and a Monte Carlo molecular dynamics code. The results of these calculations indicate that only very low energy (60–120eV) incident hydrogen ions can be used to avoid displacing atoms in the sample. At these energies, the critical cone angles are quite large and it would be necessary to position the molecular samples very close to the tip (down to only 1nm) so that the projected ion maps are interpretable as distinct threads. Projecting distinct shadows is not supported by the scattering physics.