The examples below show typical ion orbits in the radial direction inside the EBIT. In 3D the orbits are cycloids due to the axial motion of the ions. On the pictures the center yellow part represents the electron beam. In reality it has a diameter of about 60 µm and a centimeter of about 4000 amps per square current density. By comparing the four different orbits one can see that there are some ions which spend their entire time inside the beam and some of them spend most of their time outside it. This is an important point if we consider that the ions can interact with the electrons (e.g., got excited or further ionized) only when they are inside the beam.