The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

A device for collimation or focusing of a relativistic electron packet, obtained in particular by laser-plasma acceleration, including a gas cloud and a laser capable of emitting a laser pulse focused in the gas cloud in order to create therein a wave of focusing electric and magnetic fields. The invention also relates to a device for emission of a collimated or focused relativistic electron packet. The invention further relates to a collimation or focusing method for a relativistic electron packet, and to methods for emission of a collimated or focused relativistic electron packet.

A device for collimation or focusing of a relativistic electron packet, obtained in particular by laser-plasma acceleration, including a gas cloud and a laser capable of emitting a laser pulse focused in the gas cloud in order to create therein a wave of focusing electric and magnetic fields. The invention also relates to a device for emission of a collimated or focused relativistic electron packet. The invention further relates to a collimation or focusing method for a relativistic electron packet, and to methods for emission of a collimated or focused relativistic electron packet.

According to one embodiment, a klystron includes an electron gun unit, a plurality of resonant cavities, a collector, and a plurality of drift tubes. The resonant cavities include an input cavity, a plurality of intermediate cavities, and an output cavity, positioned sequentially along the traveling direction of electrons from the electron gun unit. The intermediate cavities include a plurality of second harmonic cavities. The collector captures the electrons that have passed through the resonant cavities. The drift tubes are provided between the electron gun unit and the input cavity, between the resonant cavities, and between the output cavity and the collector.

The purpose is to make it possible to autonomously suppress a reduction in an electron beam without providing a means for supervising the electron beam intensity of a monitor or the like. An electron gun, provided with: a heater (12) in which one terminal serves as a heater terminal (H) and the other terminal serves as a shared terminal (HK), and in which a low-voltage power supply (21) is connected between the terminals, the heater (12) generating heat due to a current being supplied from the low-voltage power supply (21); and a cathode electrode (11) connected to the shared terminal (HK) and heated by the heater (12) to discharge thermal electrons. A cathode current (Ik) due to the thermal electrons discharged from the cathode electrode (11), and a current (Ih) due to the low-voltage power supply, flow in opposite directions through the heater (12).

A device for collimation or focusing of a relativistic electron packet, obtained in particular by laser-plasma acceleration, including a gas cloud and a laser capable of emitting a laser pulse focused in the gas cloud in order to create therein a wave of focusing electric and magnetic fields. The invention also relates to a device for emission of a collimated or focused relativistic electron packet. The invention further relates to a collimation or focusing method for a relativistic electron packet, and to methods for emission of a collimated or focused relativistic electron packet.

A device for collimation or focusing of a relativistic electron packet, obtained in particular by laser-plasma acceleration, including a gas cloud and a laser capable of emitting a laser pulse focused in the gas cloud in order to create therein a wave of focusing electric and magnetic fields. The invention also relates to a device for emission of a collimated or focused relativistic electron packet. The invention further relates to a collimation or focusing method for a relativistic electron packet, and to methods for emission of a collimated or focused relativistic electron packet.

The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

A Tera Hertz reflex klystron includes an electron emission unit, a resonant unit and an output unit. The electron emission is used to emit a plurality of electrons. The electron emission unit defines a first opening. The resonant unit comprises a resonant cavity frame. The resonant cavity frame comprises a top wall and a bottom wall and defines a resonant cavity. The top wall and the bottom wall faces with each other. The bottom wall comprises a bottom opening. The top wall comprises a top opening and at least one outputting hole. The bottom opening and the first opening are merged with each other. The output unit being configured to output Tera Hertz waves. The plurality of electrons are transferred to the output unit from the at least one outputting hole.