Electron trajectory tracer associated with resistance network analogs

For the design of the electronic apparatus which makes use of electron beam, it is essential to know electron trajectories in its electron optical system. This problem includes two sub-j ects; the first is to know the electric and magnetic field distributions in a given elec-trode-and magnetic pole-system, and the second to determine electron paths with the knowledge of the fields. The electron trajectory tracer described in this paper has two resistance networks for solution of electric and magnetic fields, and analog computers for the determination of electron paths. Some tracers using a resistance network analog for solving electric field were already reported [1], [2]. Ours is, however, distinguished from them in two points: the first is that a resistance network analog for magnetic field is added to that for electric field and the second that, for integration of the equation of motion, analog computers are used. Accordingly, the first advantage of our tracer consists in the capability of dealing with the problems involving magnetic field. It possesses, moreover, several other advantages due to the use of analog computers, such as the ease of handling and the direct visualization of electron motion.