Investigation of hysteresis in high current ion beam guiding through micro-glass capillary: time and dimension dependence

Guiding of high current density (0.1–3 A m⁻²) argon ion beams through a straight and tapered micro-glass-capillary is studied. It is observed that the ion beam requires a minimum threshold energy to pass through the capillary. The variation of beam current with applied voltage exhibits hysteresis due to the charges accumulated on the inner wall of the capillary. The dependence of hysteresis and beam transmission on the time interval between successive experiments including capillary dimensions and geometry are investigated. The guiding capability of a tapered capillary is demonstrated where beam size reduction without compromising total current is achieved. A particle-in-cell simulation code, developed by solving the Poisson’s equation and the equation of motion simultaneously, shows reasonable agreement with the experimental results. (paper)