Patent ID: 8716958

Claim:
A microwave device for accelerating electrons, comprising: an electron gun providing an electron beam along an axis ZZ′, a microwave structure for accelerating the electrons of the beam provided by the electron gun, the microwave structure having, along the axis ZZ′, two opposite ends, one of the ends on the electron gun side comprising an input for the electron beam, the other end comprising an output for the accelerated electrons of the beam, between the two ends of the microwave structure, a series of n coupled cavities C 1 , C 2 , . . . Ci, . . . Cx, . . . Cn, along said axis ZZ′, of central resonant frequency f 0 , x being a rank of the cavity in the series of n coupled cavities, the microwave structure having an input for a microwave signal Urf for excitation by an input cavity Ci forming part of the series of n coupled cavities, a radiofrequency generator controllable in terms of a frequency Fv comprising a frequency control input, a microwave output providing the excitation microwave signal Urf at the frequency Fv to the microwave signal input of the microwave structure, a central unit UC providing a signal for controlling the frequency Fv to the frequency control input of the radiofrequency generator, the input cavity Ci being a cavity closer to the end of the microwave structure on the electron gun side than to the other end of the microwave structure comprising the output for the accelerated electrons, the central unit UC is configured to control at least the frequency Fv of the radiofrequency generator around the central resonant frequency f 0 so as to provide at the output of the microwave structure a series of pulses I 1 , I 2 , I 3 , . . . Iy, . . . of accelerated electrons of respective energy levels E 1 , E 2 , E 3 , . . . Ey, . . . varying from one pulse Iy to the next I(y+1), y being the rank of the pulse in the series of pulses, a frequency Fvy of the excitation signal Urf during a pulse Iy producing an energy Ey of the accelerated electrons at the output of the microwave structure.