🧲 Wien Velocity Selector and Sector Magnet: Isotope Separation by Mass (2D)

Top view of an ion beam crossing a velocity selector with perpendicular electric and magnetic fields, then curving through a 180 degree magnetic sector onto a detector. Set the electric field, both magnetic fields, ion speed, speed spread and slit width, and watch 20, 22 and 24 mass-unit ions split by radius. Boris-integrated trajectories are compared with the cycloid and circle formulae in four in-page numerical checks. A field-physics companion to the 3D isotope separator.