3D-Printed Plasma Cathode Electron Source for Educational Purposes

In secondary education, cathode-ray tubes (CRTs) are often the first choice when it comes to investigating the behavior of electrically charged particles in electric and magnetic fields.While CRTs offer some advantages, mainly from a practical point of view, they are on the whole ill-suited for an inquiry-based approach since they provide very limited room for modification or hands-on experimentation. Therefore, a 3D-printable plasma electron gun has been developed, which is at the same time modular, inexpensive, and easily accessible. The main objective is to provide teachers and students with an easy-to-operate electron beam source that allows conducting experiments on beam generation, beam focusing, and beam deflection as a hands-on activity in a classroom setting. From a technical point of view, this can be achieved by substituting the hot cathode as standard electron source by a plasma cathode electron gun, which can be operated at fore-vacuum pressure and in reactive gases. We provide a proof of concept that a low-cost 3D-printed plasma electron source is feasible and that beam generation can be accomplished.