Incident energy and charge deposition dependences of electron transmission through a microsized tapered glass capillary

An experimental study of electron transmission and guiding through a tapered glass capillary has been performed. Electrons were transmitted for tilt angles up to ∼6.5° and ∼9.5° (laboratory angles) for incident energies of 500 and 1000eV, respectively. It is found that elastic and inelastic contributions give rise to distinguishable peaks in the transmitted profile. For 500eV elastic transmission dominates the profile, while for 1000eV both elastic and inelastic contributions are present. The transmission for both energies was studied as a function of the charge (time) deposition and found to be strongly dependent. Results suggest fundamental differences between 500 and 1000eV incident electrons. For 500eV the transmission slowly increases suggesting charge up of the capillary wall, reaching relative stability with infrequent breakdowns for all angles investigated. For 1000eV for tilt angles near zero degrees the time dependent profile shows oscillations in the transmission, which never reached a stable condition, while for the larger angle investigated the transmission reached near equilibrium. Inelastic processes dominated the transmission for 1000eV even at very small tilt angles, but was generally elastic (due to Coulomb deflection) for 500eV even for the largest tilt angle measured.