Apparatuses and methods for accelerating charged particles including a charged particle source configured to provide charged particles, an accelerator including: a cavity having one or more inlets and one or more outlets, an electro-magnet substantially surrounding at least a portion of the cavity, a conductor disposed longitudinally within the cavity configured to accelerate the charged particles entering the cavity through the one or more inlets via a radio frequency wave applied to the cavity, wherein the radio frequency wave operates in transverse electromagnetic mode, and a target configured to receive the accelerated charged particles via the one or more outlets.

A compact light source based on electron beam accelerator technology includes a storage ring, a booster ring, a linear accelerator and an undulator for providing light having the characteristics for actinic mask inspection at 13.5 nm. The booster ring and the storage ring are located at different levels in a concentric top view arrangement in order to keep the required floor space small and to reduce interference effects. Quasi-continuous injection by enhanced top-up injection leads to high intensity stability and combats lifetime reductions due to elastic beam gas scattering and Touschek scattering. Injection into the storage ring and extraction from the booster ring are performed diagonal in the plane which is defined by the parallel straight section orbits of the booster ring and the storage ring. For the top-up injection from the booster ring into the storage ring two antisymmetrically arranged Lambertson septa are used.

A compact light source based on electron beam accelerator technology includes a storage ring, a booster ring, a linear accelerator and an undulator for providing light having the characteristics for actinic mask inspection at 13.5 nm. The booster ring and the storage ring are located at different levels in a concentric top view arrangement in order to keep the required floor space small and to reduce interference effects. Quasi-continuous injection by enhanced top-up injection leads to high intensity stability and combats lifetime reductions due to elastic beam gas scattering and Touschek scattering. Injection into the storage ring and extraction from the booster ring are performed diagonal in the plane which is defined by the parallel straight section orbits of the booster ring and the storage ring. For the top-up injection from the booster ring into the storage ring two antisymmetrically arranged Lambertson septa are used.

An apparatus for generating high frequency electromagnetic radiation includes a whispering gallery mode resonator, coupled to an output waveguide through a coupling aperture. The resonator has a guiding surface, and supports a whispering gallery electromagnetic eigenmode. An electron source is configured to generate a velocity vector-modulated electron beam, where each electron in the velocity vector-modulated electron beam travels substantially perpendicular to the guiding surface, while interacting with the whispering gallery electromagnetic eigenmode in the whispering gallery mode resonator, generating high frequency electromagnetic radiation in the output waveguide.

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.

Cyclotron includes an acceleration chamber, a vacuum system, an ion source system, and a control system that is configured to determine at least one operating parameter as a particle beam is directed along a beam path of the cyclotron. The control system is configured to decrease a supply of the charged particles for the particle beam based on the at least one operating parameter. The particle beam continues after decreasing the supply of the charged particles. The control system is also configured to increase the supply of the charged particles for the particle beam after a predetermined time period or in response to determining that an amount of gas molecules has reduced based on the at least one operating parameter.

Cyclotron includes an acceleration chamber, a vacuum system, an ion source system, and a control system that is configured to determine at least one operating parameter as a particle beam is directed along a beam path of the cyclotron. The control system is configured to decrease a supply of the charged particles for the particle beam based on the at least one operating parameter. The particle beam continues after decreasing the supply of the charged particles. The control system is also configured to increase the supply of the charged particles for the particle beam after a predetermined time period or in response to determining that an amount of gas molecules has reduced based on the at least one operating parameter.

The accelerator includes a circular vacuum container which contains a circular return yoke. With respect to the central axis of the vacuum container, an incidence electrode is arranged towards the entrance of a beam emission path inside of the return yoke. Inside of the return yoke, electrodes are arranged radially from the incidence electrode in the periphery of the incidence electrode. Recesses are arranged alternately with the electrodes in the circumferential direction of the return yoke. In the vacuum container, an orbit-concentric region is formed in which multiple beam orbits centered on the incidence electrode are present, and, in the periphery of said region, an orbit-eccentric area is formed in which multiple beam orbits eccentric to the incidence electrode are present. In the orbit-eccentric region, the beam orbits between the incidence electrode and the entrance to the beam emission path are denser.

A photocathode comprises a substrate in which a cavity is formed and a film of material disposed on the substrate. The film of material comprises an electron emitting surface configured to emit electrons when illuminated by a beam of radiation. The electron emitting surface is on an opposite side of the film of material from the cavity.