Simulation of guiding of highly charged projectiles through insulating nanocapillaries

Abstract

Recent experiments have demonstrated that highly charged ions can be guided through insulating nanocapillaries along the direction of the capillary axis for a surprisingly wide range of injection angles. Even more surprisingly, the transmitted particles remain predominantly in their initial charge state, thus opening the pathway to the construction of novel ion-optical elements without electric feedthroughs. We present a theoretical treatment of this self-organized guiding process.We develop a classical trajectory transport theory that relates the microscopic charge-up with macroscopic material properties. Transmission coefficients, angular spread of transmitted particles, and discharge characteristics of the target are investigated. Partial agreement with experiment is found.

Simulation of guiding of multiply charged projectiles through insulating capillaries

“…The force experienced by the n th ion depends on the history of all previous trajectories {R considering them to be independent from the stage of charge-up, we treat the discharge process in linear response, i.e. we neglect non-linear processes discussed recently [13,14,15].…”

Dynamic guiding process of 10-keV O−ions transmitting through Al2O3nanocapillaries

“…The guiding of slow highly charged ions is caused by the self-organized charges on the inner capillary wall [3][4][5][6][7][8][9][10][11][12][13][14][15]. Moreover, Skog et al [12,13] investigated the dynamic effects of the guiding process for Ne 7+ ions through SiO 2 nanocapillaries.…”

Experiments and simulations of 4.5-keVAr7+−ionguiding through a conical glass macrocapillary

“…Such beams are important for various applications, which include nanoscale modifications of surfaces [19], shaping of ions beams [20], focusing of exotic charged particle beams [21], and irradiation of single living cells [22], Theoretical studies provided detailed information about capillary guiding. In a series of simulations [23][24][25][26], a diffusion model was used wherein the deposited charges perform a random walk along the surface and inside the bulk of the capillary. A different concept was adopted in recent simulations [27,28] involving a nonlinear charge transport at the capillary surface based on the formalism by Frenkel [29].…”