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.

An ion implantation system including an ion source for generating an ion beam, an end station for holding a substrate to be implanted by the ion beam, and a linear accelerator disposed between the ion source and the end station and adapted to accelerate the ion beam, the linear accelerator comprising at least one acceleration stage including a resonator coil coupled to a drift tube assembly, the drift tube assembly including a first drift tube coupled to a first end of a first insulting rod via interference fit, a second drift tube coupled to a first end of a second insulting rod via interference fit, and a mounting bracket coupled to a second end of the first insulting rod and to a second end of the second insulting rod via interference fit.

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 pulses having different energy levels or different dose.

A high gradient linear accelerating structure can propagate high frequency waves at a negative harmonic to accelerate low-energy ions. The linear accelerating structure can provide a gradient of 50 MV/m for particles at a of between 0.3 and 0.4. The high gradient structure can be a part of a linear accelerator configured to provide an energy range from an ion source to 450 MeV/u for .sup.12C.sup.6+ and 250 MeV for protons. The linear accelerator can include one or more of the following sections: a radiofrequency quadrupole (RFQ) accelerator operating at the sub-harmonic of the S-band frequency, a high gradient structure for the energy range from 45 MeV/u to 450 MeV/u.

A method for constructing a photon source model function of a medical linear accelerator, for calculating the dose of rays in a radiation therapy scheme is disclosed. A source model of a therapeutic photon beam of the accelerator includes a primary ray photon source model and a scattered ray photon source model. Physical parameters in the two parts of source model functions include the position coordinates of an emission point of a particle, a projection value of a unit momentum vector in a three-dimensional orthogonal direction, and the energy of the particle. By utilizing the model functions, photon fluence information, energy spectrum information, and unit momentum direction information of photons on any phase space plane can be accurately calculated. The method and thought for constructing the source model are applicable to construction of source models of photon beams with various nominal energies of the accelerator used in a radiation therapy.

A method for constructing a photon source model function of a medical linear accelerator, for calculating the dose of rays in a radiation therapy scheme is disclosed. A source model of a therapeutic photon beam of the accelerator includes a primary ray photon source model and a scattered ray photon source model. Physical parameters in the two parts of source model functions include the position coordinates of an emission point of a particle, a projection value of a unit momentum vector in a three-dimensional orthogonal direction, and the energy of the particle. By utilizing the model functions, photon fluence information, energy spectrum information, and unit momentum direction information of photons on any phase space plane can be accurately calculated. The method and thought for constructing the source model are applicable to construction of source models of photon beams with various nominal energies of the accelerator used in a radiation therapy.

A Hybrid (SW+TW) Linear Accelerator is disclosed having high beam efficiency and broad energy regulation that is useful for security inspection, non-destructive testing, radiotherapy, and electron beam irradiation of objects. The Hybrid Linear Accelerator (LINAC) provides superior energy regulation, and includes a reversed RF power distribution which substantially improves RF power utilization, thereby eliminating need for an output RF load, and ensuring broad electron beam energy regulation operating in a broad range of input RF power, thereby efficiently running at a variety of input electron beam current intensities at high efficiency. The Hybrid LINAC may be equipped with a fast and/or slow phase shifter and/or a power regulator having a phase shifter and a current regulator, while operating much more efficiently than known LINACS. The Hybrid LINAC permits efficient operation without an external magnetic field, thereby avoiding use of a power-consuming solenoid, consequently reducing cost of production, operation, and maintenance.

A Hybrid (SW+TW) Linear Accelerator is disclosed having high beam efficiency and broad energy regulation that is useful for security inspection, non-destructive testing, radiotherapy, and electron beam irradiation of objects. The Hybrid Linear Accelerator (LINAC) provides superior energy regulation, and includes a reversed RF power distribution which substantially improves RF power utilization, thereby eliminating need for an output RF load, and ensuring broad electron beam energy regulation operating in a broad range of input RF power, thereby efficiently running at a variety of input electron beam current intensities at high efficiency. The Hybrid LINAC may be equipped with a fast and/or slow phase shifter and/or a power regulator having a phase shifter and a current regulator, while operating much more efficiently than known LINACS. The Hybrid LINAC permits efficient operation without an external magnetic field, thereby avoiding use of a power-consuming solenoid, consequently reducing cost of production, operation, and maintenance.

A method for the suppression of upstream-directed field emission in RF accelerators. The method is not restricted to a certain number of cavity cells, but requires similar operating field levels in all cavities to efficiently annihilate the once accumulated energy. Such a field balance is desirable to minimize dynamic RF losses, but not necessarily achievable in reality depending on individual cavity performance, such as early Q.sub.0-drop or quench field. The method enables a significant energy reduction for upstream-directed electrons within a relatively short distance. As a result of the suppression of upstream-directed field emission, electrons will impact surfaces at rather low energies leading to reduction of dark current and less issues with heating and damage of accelerator components as well as radiation levels including neutron generation and thus radio-activation.

A linear proton accelerator includes a plurality of accelerator components arranged after one another, and a proton source and a plurality of accelerating units. The accelerator further includes a reticular support structure for supporting the accelerator components. The support structure is shaped as a prism with a polygonal cross-section, and has a plurality of side faces joining opposite ends of the prism. The support structure is arranged concentrically with respect to the accelerator components.