Apparatuses and methods for accelerating electrons including an electron source configured to provide a beam of electrons and an accelerator utilize electron cyclotron resonance acceleration (eCRA). The accelerator includes a radio frequency (RF) cavity having a longitudinal axis, one or more inlets, and one or more outlets and an electromagnet substantially surrounding at least a portion of the cavity and configured to produce an axial magnetic field. At least one pair of waveguides couple the cavity to an RF source configured to generate an RF wave. The RF wave is a superposition of two orthogonal TE.sub.111 transverse electric modes excited in quadrature to produce an azimuthally rotating standing-wave mode configured to accelerate the beam of electrons axially entering the cavity with non-linear cyclotron resonance acceleration.

An apparatus may include an exciter, disposed within a resonance chamber, to generate an RF power signal. The apparatus may include a resonator coil, disposed within the resonance chamber, to receive the RF power signal, and generate an RF output signal; and a pickup loop assembly, to receive the RF output signal and output a pickup voltage signal. The pickup loop assembly may include a pickup loop, disposed within the resonance chamber; and a variable attenuator, disposed at least partially between the resonator coil and the pickup loop. The variable attenuator may include a configurable portion, movable from a first position, attenuating a first amount of the RF output signal, to a second position, attenuating a second amount of the RF output signal, different from the first amount.

Electromagnetic waves for an accelerating structure of the radiation delivery system are generated by a microwave source. The electromagnetic waves generated by the microwave source are adjusted by an energy adjuster to a first energy level. A kilovolt (kV) imaging beam is generated by the accelerating structure based on the first energy level. The electromagnetic waves generated by the magnetic source are adjusted by the energy adjuster to a second energy level. A megavolt (MV) treatment beam is generated by the accelerating structure based on the second energy level.

Provided is a radiation generation apparatus that can be downsized while improving power efficiency compared with a normal conduction accelerating tube. The radiation generation apparatus includes: an accelerating tube in which an accelerating cavity is defined by a tubular-shaped housing having conductivity and a plurality of cells made of a dielectric material, center openings of the cells being aligned so as to be communicated with each other in a direction in which the cells are arranged in the housing; an RF amplifier that supplies a high-frequency power to the accelerating tube; and an electron gun that emits a charged particle passing through the opening of each of the cells in the accelerating tube.

Provided is a radiation generation apparatus that can be downsized while improving power efficiency compared with a normal conduction accelerating tube. The radiation generation apparatus includes: an accelerating tube in which an accelerating cavity is defined by a tubular-shaped housing having conductivity and a plurality of cells made of a dielectric material, center openings of the cells being aligned so as to be communicated with each other in a direction in which the cells are arranged in the housing; an RF amplifier that supplies a high-frequency power to the accelerating tube; and an electron gun that emits a charged particle passing through the opening of each of the cells in the accelerating tube.

A device for generating soft x-rays includes an electron source configured to generate an electron beam comprising electron micro-bunches; an electron accelerator configured to accelerate the electron micro-bunches from the electron source; and a laser configured to generate a laser beam (536) colliding with the accelerated electron micro-bunches (534) in a counterpropagating direction to generate the soft x-rays by inverse Compton scattering. The electron source has a magneto-optical trap configured to produce an ultracold atomic gas; two counterpropagating excitation laser beams configured to produce a standing wave for inducing a periodic spatial modulation of the ultracold atomic gas along a beam propagation direction; and an ionization laser configured to induce photo-ionization of the ultracold atomic gas.

A device for generating soft x-rays includes an electron source configured to generate an electron beam comprising electron micro-bunches; an electron accelerator configured to accelerate the electron micro-bunches from the electron source; and a laser configured to generate a laser beam (536) colliding with the accelerated electron micro-bunches (534) in a counterpropagating direction to generate the soft x-rays by inverse Compton scattering. The electron source has a magneto-optical trap configured to produce an ultracold atomic gas; two counterpropagating excitation laser beams configured to produce a standing wave for inducing a periodic spatial modulation of the ultracold atomic gas along a beam propagation direction; and an ionization laser configured to induce photo-ionization of the ultracold atomic gas.

Methods and systems for bolted joint conduction cooling of accelerator cavities comprises a conduction cooling system. The conduction cooling system comprises mounting at least one cooling ring to a cavity and a conduction link joined to the cooling ring with at least one connection assembly. The materials in the at least one connection assembly can be selected to experience greater thermal contraction than the cooling ring and the conduction link when cooled. A fast conduction cooling system can comprise a cryocooler in thermal communication with a conduction cooling apparatus affixed to a cavity via a conduction path and a thermal switch in the conduction path between the cryocooler and the conduction cooling apparatus wherein a thermal conductance of the thermal switch decreases as a function of temperature.

Methods and systems for bolted joint conduction cooling of accelerator cavities comprises a conduction cooling system. The conduction cooling system comprises mounting at least one cooling ring to a cavity and a conduction link joined to the cooling ring with at least one connection assembly. The materials in the at least one connection assembly can be selected to experience greater thermal contraction than the cooling ring and the conduction link when cooled. A fast conduction cooling system can comprise a cryocooler in thermal communication with a conduction cooling apparatus affixed to a cavity via a conduction path and a thermal switch in the conduction path between the cryocooler and the conduction cooling apparatus wherein a thermal conductance of the thermal switch decreases as a function of temperature.

A radio-frequency (RF) generator arrangement includes a combiner that includes an RF plug socket and an RF generator including a plug that matches the RF plug socket. The RF plug socket includes an opening for receiving the plug, an external contact for connection to an earth connection, an internal contact for connection to an RF signal, and an opening-narrowing device configured to reduce the opening so that the opening assumes a reduced-opening state when the plug is removed. In the reduced-opening state, an opening distance of the opening is reduced compared to a first opening distance, and/or an opening cross section of the opening is reduced compared to a first opening cross section. The opening-narrowing device includes an electrically conductive barrier connected to the external contact and configured to prevent electromagnetic radiation of the RF signal emitted from the internal contact from exiting from the opening in the reduced-opening state.