= Solution
\b[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.<Optimal acceleration voltage for near-atomic resolution imaging of layer-stacked 2D polymer thin films by Baokun Liang and others>[2022, accelerating-voltage comparison and discussion of the inelastic scattering cross-section]{ref}
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