Patent ID: 8284898

Claim:
A method for generating electrons of different energies using a standing wave linear accelerator, the method comprising: (a) coupling a first electromagnetic wave into a longitudinal passageway of said standing wave linear accelerator, said first electromagnetic wave comprising a first plurality of crests; (b) applying a first electron beam current and a first voltage to an electron gun to eject a first set of electrons from said electron gun into said longitudinal passageway, said first electromagnetic wave accelerating said first set of electrons along the longitudinal passageway to a first energy, the first voltage being selected such that said first electromagnetic wave accelerates said first set of electrons at or near multiple crests of said first plurality of crests; (c) coupling a second electromagnetic wave into said longitudinal passageway, said second electromagnetic wave comprising a second plurality of crests; and (d) applying a second electron beam current and a second voltage to said electron gun to eject a second set of electrons from said electron gun into said longitudinal passageway, said second electromagnetic wave accelerating said second set of electrons along the longitudinal passageway to a second energy different from said first energy, the second voltage being different from the first voltage and selected such that said second electromagnetic wave accelerates said second set of electrons at or near multiple crests of said second plurality of crests.