In one exemplary aspect, the subject matter described in this specification can be embodied in an energy extraction system that includes a decelerator cavity coupled to a transport line for a charged particle beam and an energy conversion device coupled to the decelerator cavity. The decelerator cavity is configured to extract energy from the charged particle beam traveling through the decelerator cavity as RF energy. The energy conversion is configured to convert the RF energy into electrical current and supply the electrical current to an electric power grid. The charged particle beam includes charged particles with individual rest masses greater than the rest mass of an electron.

A reflective optical system (100) comprising at least one reflective aspheric surface (1) of focal length f.sub.0 and optical axis (Z), the surface being configured so that an incident laser beam (2) propagating along an axis (Z′) is focused along the optical axis (Z) with a FWHM ((Full Width at Half Maximum) of the intensity of the reflected beam along the optical axis (Z) being larger, preferably by a factor of at least 10, than the FWHM of the intensity of a focused beam reflected by a parabola having same focal length f.sub.0 and same optical axis (Z), receiving same beam.

A method for providing an ensemble of beamlets effectively acting as a high-energy laser pulse is disclosed. According to the method, a beamlet pattern with a plurality of spatially distributed laser beamlets is provided. The beamlets are spread in time by introducing a different temporal delay to each of the beamlets. The beamlets are spectrally broadened. The beamlets are incoherently combined in space and time to provide the ensemble of beamlets. Also disclosed is a method for accelerating charged particles. Further disclosed is an optical arrangement for providing an ensemble of beamlets effectively acting as a high-energy laser pulse. The optical arrangement comprises a beamlet generating device providing a beamlet pattern of spatially distributed laser beamlets, a step optic for spreading the spatially distributed laser beamlets in time, a spectral broadening device, and a combining device for incoherently combining the spectrally broadened beamlets in space and time to provide the ensemble of beamlets. Additionally disclosed is a laser-plasma accelerator comprising the optical arrangement.

A method for providing an ensemble of beamlets effectively acting as a high-energy laser pulse is disclosed. According to the method, a beamlet pattern with a plurality of spatially distributed laser beamlets is provided. The beamlets are spread in time by introducing a different temporal delay to each of the beamlets. The beamlets are spectrally broadened. The beamlets are incoherently combined in space and time to provide the ensemble of beamlets. Also disclosed is a method for accelerating charged particles. Further disclosed is an optical arrangement for providing an ensemble of beamlets effectively acting as a high-energy laser pulse. The optical arrangement comprises a beamlet generating device providing a beamlet pattern of spatially distributed laser beamlets, a step optic for spreading the spatially distributed laser beamlets in time, a spectral broadening device, and a combining device for incoherently combining the spectrally broadened beamlets in space and time to provide the ensemble of beamlets. Additionally disclosed is a laser-plasma accelerator comprising the optical arrangement.

A linear accelerator comprises a plurality of cyclotrons arranged axially in a cyclotron stack, each cyclotron having a set of dees and a central aperture passing through the set of dees. Each central aperture is axially aligned with one another in the stack, forming a central channel having an inlet and an outlet that passes through the stack. Magnets are positioned so as to generate a magnetic field perpendicular to the set of dees. A power supply applies an oscillating voltage to each set of dees of the stack. In operation, subatomic particles are ejected radially outwardly of the stack, creating a dead zone within the central channel that is void of particles and electromagnetic fields. A mass or light beam is accelerated as it passes through the central channel's dead zone, due to the absence of frictional forces acting on the mass or light within the dead zone.

An electromagnetic accelerator system may include a barrel defining a bore through which an acceleration path extends. An electromagnetic coil may be positioned around the barrel such that the acceleration path extends through a core of the electromagnetic coil. A first electrical contact may be positioned along the acceleration path approximately within the core of the electromagnetic coil and electrically coupled to the electromagnetic coil. A second electrical contact may position along the acceleration path approximately within the core of the electromagnetic coil and spaced apart from the first electrical contact. The second electrical contact may be electrically coupleable to the first electrical contact to complete a circuit when a projectile to be accelerated is positioned therebetween.

A method of accelerating charged particles in a plasma and an associated plasma accelerator and electromagnetic radiation source, the method including creating a region of non-uniform electric field within the plasma which propagates through the plasma; using the non-uniform electric field to accelerate a first plurality of charged particles in the direction of propagation of the region of non-uniform electric field; and once the accelerating first plurality of charged particles have propagated part-way through the plasma: adding a second plurality of charged particles to the plasma, such that the second plurality of charged particles propagates through the plasma, the second plurality of charged particles create a local distortion in the non-uniform electric field experienced by the accelerating first plurality of charged particles, and the local distortion in the non-uniform electric field propagates through the plasma with the accelerating first plurality of charged particles; and the method also including using the local distortion in the non-uniform electric field to accelerate the first plurality of charged particles in the direction of propagation of the region of non-uniform electric field.

A method of accelerating charged particles in a plasma and an associated plasma accelerator and electromagnetic radiation source, the method including creating a region of non-uniform electric field within the plasma which propagates through the plasma; using the non-uniform electric field to accelerate a first plurality of charged particles in the direction of propagation of the region of non-uniform electric field; and once the accelerating first plurality of charged particles have propagated part-way through the plasma: adding a second plurality of charged particles to the plasma, such that the second plurality of charged particles propagates through the plasma, the second plurality of charged particles create a local distortion in the non-uniform electric field experienced by the accelerating first plurality of charged particles, and the local distortion in the non-uniform electric field propagates through the plasma with the accelerating first plurality of charged particles; and the method also including using the local distortion in the non-uniform electric field to accelerate the first plurality of charged particles in the direction of propagation of the region of non-uniform electric field.

Systems and methods for generating tunable x-ray emissions including a tunable x-ray source that includes a driver, such as a laser, configured to generate one or more driver pulses, such as one or more laser pulses, and a target source configured to emit a target material. The target source is arranged so that the emitted target material intersects a propagation axis of the driver pulse(s) and the target source may be configured so that the emitted target material has a tailored density profile along the propagation axis of the driver pulse(s), the tailored density profile along the propagation axis having a first density peak region followed by a lower density region followed by a second density peak region, e.g., in an “M” shape.

The present invention relates to an ion generation composite target for an ion irradiation technology including: a substrate having a through hole formed thereon; and a graphene thin film configured on the substrate, across the through hole, having a thickness in a range between 1 nm to 3 nm, and ionized to release a proton or a carbon ion.