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 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.

The invention, which relates to a miniaturizable plasma thruster, consists of: igniting the plasma by microhollow cathode discharge close to the outlet and inside the means for injecting the propellant gas, said injection means being magnetic and comprising a tip at the downstream end thereof; bringing the electrons of the magnetized plasma into gyromagnetic rotation, at the outlet end of said injection means; sustaining the plasma by means of Electron Cyclotron Resonance (ECR), said injection means being metal and being used as an antenna for electromagnetic (EM) emission, the volume of ECR plasma at the outlet of said injection means being used as a resonant cavity of the EM wave; accelerating the plasma in a magnetic nozzle by diamagnetic force, the ejected plasma being electrically neutral.

The invention, which relates to a miniaturizable plasma thruster, consists of: igniting the plasma by microhollow cathode discharge close to the outlet and inside the means for injecting the propellant gas, said injection means being magnetic and comprising a tip at the downstream end thereof; bringing the electrons of the magnetized plasma into gyromagnetic rotation, at the outlet end of said injection means; sustaining the plasma by means of Electron Cyclotron Resonance (ECR), said injection means being metal and being used as an antenna for electromagnetic (EM) emission, the volume of ECR plasma at the outlet of said injection means being used as a resonant cavity of the EM wave; accelerating the plasma in a magnetic nozzle by diamagnetic force, the ejected plasma being electrically neutral.

The invention comprises a multi-axis charged particle irradiation method and apparatus. The multi-axis controls includes separate or independent control of one or more of horizontal position, vertical position, energy control, and intensity control of the charged particle irradiation beam. Optionally, the charged particle beam is additionally controlled in terms of timing. Timing is coordinated with patient respiration and/or patient rotational positioning. Combined, the system allows multi-axis and multi-field charged particle irradiation of tumors yielding precise and accurate irradiation dosages to a tumor with distribution of harmful proximal distal energy about the tumor.

The invention comprises a multi-axis charged particle irradiation method and apparatus. The multi-axis controls includes separate or independent control of one or more of horizontal position, vertical position, energy control, and intensity control of the charged particle irradiation beam. Optionally, the charged particle beam is additionally controlled in terms of timing. Timing is coordinated with patient respiration and/or patient rotational positioning. Combined, the system allows multi-axis and multi-field charged particle irradiation of tumors yielding precise and accurate irradiation dosages to a tumor with distribution of harmful proximal distal energy about the tumor.

A method of generating electromagnetic fields comprises the step of using the interaction between a laser source and an appropriate target, as the source for generating high-intensity electromagnetic fields. A strong positive charge is generated in the target hit by the laser. The target has a structure consisting of at least two different elements. The method can be used to obtain the acceleration, deceleration, deflection, focusing or selection of moving charges. Such charges have been previously accelerated by a completely separate process, and therefore the two processes of pre-acceleration and subsequent processing of the beam of particles are completely separate and therefore separately tunable and optimizable Such electromagnetic fields can be used in other fields than those previously indicated, such asmerely by way of examplemedicine, biology, studies on materials, electromagnetic compatibility, and generation of terahertz radiation.

An annular apparatus is provided for generating accelerated electrons, wherein ions from a glow discharge plasma may be accelerated onto the surface of an annular second cathode and electrons emitted by the annular second cathode may be accelerated towards an annular electron exit window by a second electrical voltage applied between the annular second cathode and an annular second anode, wherein a housing is designed as a first cathode; a first anode comprises a number of wire-like electrodes which extend completely or partially through an annular evacuable space, and wherein a second reservoir contains a hydrocarbon-containing compound which may be admitted into the evacuable space through the at least one first inlet.

An annular apparatus is provided for generating accelerated electrons, wherein ions from a glow discharge plasma may be accelerated onto the surface of an annular second cathode and electrons emitted by the annular second cathode may be accelerated towards an annular electron exit window by a second electrical voltage applied between the annular second cathode and an annular second anode, wherein a housing is designed as a first cathode; a first anode comprises a number of wire-like electrodes which extend completely or partially through an annular evacuable space, and wherein a second reservoir contains a hydrocarbon-containing compound which may be admitted into the evacuable space through the at least one first inlet.

Embodiments of systems, devices, and methods relating to a beam system. An example method of detecting beam misalignment a beam system includes detecting beam misalignment in an injector system of the beam system. The example method further includes detecting beam misalignment in an accelerator system of the beam system.