A synchrotron injector system comprising a first ion source which generates a first ion, a second ion source which generates a second ion having a smaller charge-to-mass ratio than a charge-to-mass ratio of the first ion, a pre-accelerator having the capability to enable to accelerate both the first ion and the second ion, a low-energy beam transport line which is constituted in such a way to inject either the first ion or the second ion into the pre-accelerator, and a self-focusing type post-accelerator which accelerates only the first ion after acceleration which is emitted from the pre-accelerator.

A linac-based X-ray system for cargo scanning and imaging applications uses linac design, RF power control, beam current control, and beam current pulse duration control to provide stable sequences of interleaved pulses having different energy levels, for example alternating 4 MeV and 6 MeV pulses or other energies where the difference in levels is at least approximately 1 MeV and less than approximately 5 MeV. The pulse repetition rate can be 100-400 pulses per second or more. In an embodiment, a cool down calculation is combined with automatic frequency control to provide stable energy and dose per pulse even upon restarting of pulsing after an off period of indeterminate duration.

A slot-coupled CW standing wave multi-cell accelerating cavity. To achieve high efficiency graded beta acceleration, each cell in the multi-cell cavity may include different cell lengths. Alternatively, to achieve high efficiency with acceleration for particles with beta equal to 1, each cell in the multi-cell cavity may include the same cell design. Coupling between the cells is achieved with a plurality of axially aligned kidney-shaped slots on the wall between cells. The slot-coupling method makes the design very compact. The shape of the cell, including the slots and the cone, are optimized to maximize the power efficiency and minimize the peak power density on the surface. The slots are non-resonant, thereby enabling shorter slots and less power loss.

A linac-based X-ray system for cargo scanning and imaging applications uses linac design, RF power control, beam current control, and beam current pulse duration control to provide stable sequences of interleaved pulses having different energy levels, for example alternating 4 MeV and 6 MeV pulses or other energies where the difference in levels is at least approximately 1 MeV and less than approximately 5 MeV. The pulse repetition rate can be 100-400 pulses per second or more. In an embodiment, a cool down calculation is combined with automatic frequency control to provide stable energy and dose per pulse even upon restarting of pulsing after an off period of indeterminate duration.

A linear accelerator comprises side-coupled cavity cells configured to accelerate electrons with a radio frequency field. The field amplitude in the initial cells is lower than in the later cells, and the initial cells are shorter than the later cells. This creates a capture section where electrons are captured and bunched while experiencing low acceleration, followed by an acceleration section where the bunched electrons experience stronger acceleration.

A particle accelerator comprising a waveguide comprising a series of acceleration cells. The series of acceleration cells comprise an input acceleration cell configured to accelerate a beam of electrons along the central axis of the cells. A source of electrons is configured to input a beam of electrons into the input acceleration cell and a magnet arrangement is configured to prevent electrons that have deviated from the beam of electrons from hitting the source of electrons.

Methods for generating a multiple-energy X-ray pulse. A beam of electrons is generated with an electron gun and modulated prior to injection into an accelerating structure to achieve at least a first and specified beam current amplitude over the course of respective beam current temporal profiles. A radio frequency field is applied to the accelerating structure with a specified RF field amplitude and a specified RF temporal profile. The first and second specified beam current amplitudes are injected serially, each after a specified delay, in such a manner as to achieve at least two distinct endpoint energies of electrons accelerated within the accelerating structure during a course of a single RF-pulse. The beam of electrons is accelerated by the radio frequency field within the accelerating structure to produce accelerated electrons which impinge upon a target for generating Bremsstrahlung X-rays.

Methods for generating a multiple-energy X-ray pulse. A beam of electrons is generated with an electron gun and modulated prior to injection into an accelerating structure to achieve at least a first and specified beam current amplitude over the course of respective beam current temporal profiles. A radio frequency field is applied to the accelerating structure with a specified RF field amplitude and a specified RF temporal profile. The first and second specified beam current amplitudes are injected serially, each after a specified delay, in such a manner as to achieve at least two distinct endpoint energies of electrons accelerated within the accelerating structure during a course of a single RF-pulse. The beam of electrons is accelerated by the radio frequency field within the accelerating structure to produce accelerated electrons which impinge upon a target for generating Bremsstrahlung X-rays.

A new ring coupling structure for a linear accelerator includes an acceleration cavity, a coupling cavity, and a beam hole. The acceleration cavity and the coupling cavity are alternately assembled together. The beam hole penetrates through the acceleration cavity and the coupling cavity. The acceleration cavity adopts a bowl-shaped structure, a convex cone structure with a mesoporous is disposed on an inner wall of the acceleration cavity along the beam hole. Coupling holes between the acceleration cavity and the coupling cavity are designed as at least two waist-shaped holes uniformly distributed around the beam hole. The coupling cavity adopts a disc-shaped cavity structure with a thickened edge, and a nose cone is disposed in the coupling cavity and welded with cavity walls at both ends of a coupler. The left and right waveguide plates of the coupling cavity are welded together by using the nose cone.

An apparatus may include a drift tube assembly, comprising a plurality of drift tubes to conduct an ion beam along a beam propagation direction. The plurality of drift tubes may define a multi-gap configuration corresponding to a plurality of acceleration gaps, wherein the plurality of drift tubes further define a plurality of RF quadrupoles, respectively. As such, the plurality of quadrupoles are arranged to defocus the ion beam along a first direction at the plurality of acceleration gaps, respectively, where the first direction extends perpendicularly to the beam propagation direction.