A beam of electrons whose kinetic energy is K emerges from a thin-foil "window" at the end of an accelerator tube. A metal plate at distance d from this window is perpendicular to the direction of the emerging beam (Figure).

(a) Show that we can prevent the beam from hitting the plate if we apply a uniform magnetic field B such that B > ??2mK/e2d2 in which m and e are the electron mass and charge.

(b) How should B oriented?

Transcribed Image Text:

Foil Electron beam window- Plate Tube