Charging dynamics in electron transmission through Al2O3 capillaries

We have measured the transmission of low-energy (E=250eV) electrons through insulating Al2O3 nanocapillaries. We find that transmission at the incident energy is quickly suppressed with increasing tilt angle ψ of the capillary axis relative to the incoming electron beam while inelastic transmission becomes more important. For small angles of incidence charging dynamics lead to a decrease of total transmission (elastic and inelastic) with time. Our results are interpreted on the basis of a microscopic model for the electron transport within the capillary including also close interactions with the capillary wall.