Abstract: A radiotherapy apparatus adapted for use with a Magnetic Resonance Imaging (MRI) system, the radiotherapy apparatus comprising a linear accelerator, the linear accelerator including an electron source. In the linear accelerator electrons which are introduced by the source are accelerated to impact on a target and produce a beam of radiotherapeutic radiation. The linear accelerator has an accelerator waveguide within which the electrons are accelerated and an external waveguide enclosure; this enclosure extends substantially continuously over the accelerator waveguide.

Abstract: A radiotherapy apparatus adapted for use with a Magnetic Resonance Imaging (MRI) system, the radiotherapy apparatus comprising a linear accelerator, the linear accelerator including an electron source. In the linear accelerator electrons which are introduced by the source are accelerated to impact on a target and produce a beam of radiotherapeutic radiation. The linear accelerator has an accelerator waveguide within which the electrons are accelerated and an external waveguide enclosure; this enclosure extends substantially continuously over the accelerator waveguide.

Abstract: An exciter system (1, 2) able to communicate information between an exciter unit (10) and one or more remote units (12) or between multiple exciter units (10). The exciter units (10) may include wireless type exciter devices, such as optimum exciters (14), or they may include wired equivalent type exciter devices, such as direct connect exciters (16). The exciter devices (14, 16) inject or extract RF currents (24) in the metallic framework (22) of a vehicle. The remote units (12) couple electromagnetic fields (26) with the metallic framework (22) of the vehicle. The information is exchanged with the exciter devices (14, 16) by communications equipment (20) that modulates or demodulates the RF currents (24) and/or electromagnetic fields (26) with the information. As the RF currents (24) and/or electromagnetic fields (26) reach everywhere within, on and in close proximity to the vehicle the information is communicated throughout.

Abstract: An antenna system, particularly for vehicles. A discone-type antenna is preferably utilized for frequencies outside the vehicle. At various frequencies, either or both the antenna and the vehicle serve as exciters.