Interlaced multi-energy betatron with adjustable pulse repetition frequency

A betatron device for providing electron pulses at different energies, the betatron device comprising:

• a vacuum enclosure for electrons to orbit during acceleration portions of respective cycles;
• magnetic cores that conduct and contain magnetic flux and that shape magnetic fields at the electron orbit;
• swing coils configured to generate a swing in magnetic flux within the electron orbit and a swing component of a total magnetic field at the electron orbit over a plurality of cycles of a single output session;
• bias coils configured to generate a bias component of the total magnetic field at the electron orbit during the acceleration portions of the respective cycles;
• a bias storage device selectively coupled to the bias coils via at least a bias storage switch;
• and
• a bias power supply selectively coupled to the bias coils and the bias storage device via at least a bias power switch,
• wherein the bias storage switch and the bias power switch are configured to disconnect the bias coils from the bias power supply and transfer energy from the bias coils to the bias storage device at a particular time during a cycle of the single output session.

A method of operating a betatron device having a swing coil for accelerating electrons to provide electron pulses at adjustable cycle rates, the method comprising:

• operating the swing coils to generate a swing component of a total magnetic field at the electron orbit over a plurality of cycles, the electron orbit being a circular path in which accelerated electrons travel;
• accelerating, with the swing coils, a first packet of electrons with a first swing in flux subject to the total magnetic field during a first acceleration portion of a first cycle of the plurality of cycles;
• expanding an electron orbit of the first packet of electrons at an end of the first acceleration portion;
• after the first acceleration portion of the first cycle, storing energy of the swing component in a swing storage device as the swing component decreases;
• when a current in the swing coils decreases to zero, disengaging the swing coils from the swing storage device for a first adjustable delay time;
• and
• after the first adjustable delay time, engaging the swing coils with the swing storage device for a next cycle.

A betatron device for providing electron pulses at adjustable cycle rates, the betatron device comprising:

• a vacuum enclosure for electrons to orbit during acceleration portions of respective cycles;
• magnetic cores that conduct and contain magnetic flux and that shape magnetic fields at the electron orbit;
• swing coils configured to generate a swing in magnetic flux within the electron orbit and a swing component of a total magnetic field at the electron orbit over a plurality of cycles of a single output session;
• a swing storage device selectively coupled to the swing coils via at least a swing storage switch;
• a swing power switch configured to selectively couple a swing power supply to the swing coils and the swing storage device,
• wherein the swing storage switch is configured to engage the swing coils with the swing storage device during a cycle and to disengage the swing coils from the swing storage device for an adjustable delay time between cycles, and
• wherein the first power switch is configured to disconnect the swing power supply from the swing coils and the swing storage device during a cycle.

A method of controlling an amount of x-ray radiation dose emitted by a betatron device, the method comprising:

• adjusting a length of time of an injection pulse of electrons into a betatron device;
• accelerating a respective packet of electrons during an acceleration portion of each of a plurality of cycles while the electrons are in an electron orbit;
• expanding the electron orbit for the respective packets of electrons at an end of the acceleration portion of each cycle;
• and
• hitting a metal target with the expanded electrons to produce x-ray radiation, wherein the length of time of the injection pulse is adjusted based on a desired amount of dose output for the radiation beam.