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inorganic chemistry 56, 8295–8301 (2017). Publisher record. Primary text or institutional research record. Abstract: UV–visible oxidation-state mass balance and radiolysis model.

Displacement of an atom when a collision transfers enough momentum to exceed its displacement threshold. Its energy dependence differs from radiolysis.

Radiation changes the solution's chemistry by radiolysis; it does not turn Am(VI) nuclei into Am(V) nuclei. An emitted alpha particle deposits energy into many water and solute molecules, generating ionized/excited species, hydrated electrons, hydrogen atoms and molecular products including hydrogen peroxide. Reducing products can supply the electron needed forFor example, hydrogen peroxide can be oxidized while reducing two americyl(VI) ions:The $0.3$ mM loss of Am(VI) equals the $0.3$ mM appearance of Am(V), preserving the measured dissolved americium total while transferring $0.3\mathrm{mmol}{\mathrm{L}}^{-1}$ of electron equivalents. Oxidizing radiolysis products are also present, and the net reduction depends on acid, dissolved gases and scavengers; not every radiolytic event is reducing. In nitric acid, primary kinetic work identifies hydrogen peroxide and radiolytically produced nitrous acid as important reductants, with a rate controlled by total americium activity rather than necessarily by the instantaneous Am(VI) concentration.^[ref]

Use a low-dose, dose-efficient acquisition rather than assuming that a lower accelerating voltage is always gentler. Focus and align on a sacrificial neighbouring region, blank the beam between exposures, illuminate only when recording and use an efficient detector. A broad, low-current-density transmission electron microscopy exposure can avoid a high instantaneous local dose; scanning can also work if probe current, dwell time and repeated visits are controlled.

Radiolysis starts with inelastic scattering and ionization. For an appropriate thin specimen, increasing the electron energy can reduce the inelastic interaction probability and energy deposition per incident electron, so a relatively high voltage can help. However, increasing voltage can also activate knock-on displacement. The optimum therefore depends on the material and the amount of useful information obtained per damaging event; $150\mathrm{nm}$ alone does not determine it. Cooling may reduce diffusion-driven chemical changes but does not eliminate primary ionization. An experimental study of nonbiological layered polymer films explicitly found that the voltage choice must balance damage with image signal.^[ref]