Achieving a large detector sensitive area of short magnetic focusing pulse-dilation framing tube using a combination lens

摘要

A modified short magnetic focusing pulse-dilation framing tube was developed base on imaging characteristic of solenoid lens and short magnetic lens, by which a combination lens composed of two magnetic lenses with a soft iron shield. The spatial performance is simulated by Runge-Kutta method and the imaging distribution of electrons. The detector sensitive area and spatial resolution is measured using Au photocathode with a UV-ray mask and ultraviolet source. When the magnetic field strengths on the axis close to photocathode and microchannel plate were 31 and 56 G, respectively, and the electron image had 2:1 demagnification, the measured detector sensitive area is Phi 45 nun and the spatial resolution is about 207 mu m. The spatial performance parameter was satisfied the ICF requirement.