Apparatus and method for inhibiting the generation of excessive radiation

An apparatus for generating electron radiation or X-ray radiation, said apparatus comprising:

• accelerator means for generating and accelerating electrons to form an electron beam which has a predetermined low intensity level for the generation of said electron radiation or a predetermined high intensity level for the generation of said X-ray radiation;
• supporting means for supporting a scattering foil and a target and for selectively moving either said foil into the trajectory of said electron beam having said low intensity level for generating said electron radiation upon impingement of said electrons there or on said target into the trajectory of said electron beam having said high intensity level for generating said X-ray radiation upon impingement of said electrons thereon;
• detecting means operable by said supporting means for sensing the position of said target relative to the trajectory of said electron beam;
• and
• inhibiting means coupled to said accelerator means and to said detecting means for preventing the generation of an electron beam having said high intensity level if said foil and not said target is positioned in the trajectory of said electron beam.