摘要:
A cylindrical waveguide with a mode converter transforms a whispering gallery mode from a gyrotron cylindrical waveguide with a helical cut launch edge to a quasi-Gaussian beam suitable for conveyance through a corrugated waveguide. This quasi-Gaussian beam is radiated away from the waveguide using a spiral cut launch edge, which is in close proximity to a first mode converting reflector. The first mode converting reflector is coupled to a second mode converting reflector which provides an output free-space HE11 mode wave suitable for direct coupling into a corrugated waveguide. The radiated beam produced at the output of the second mode converting reflector is substantially circular.
摘要:
A coaxial cavity gyrotron with two electron beams includes an electron gun (magnetron injection gun, “MIG,” with two beams), a coaxial beam-wave interaction cavity and an outer magnetic field tube. The coaxial beam-wave interaction cavity consists of two parts: an outer conductor and an inner conductor. The two hollow electron beams produced by the MIG are located between the outer conductor and the inner conductor. The MIG includes inner and outer anodes, with a single cathode located between the anodes. The cathode further includes two emitter rings which produce the two hollow electron beams. The entire gyrotron is immersed in the magnetic field tube such that the magnetic field profile is the same or similar to that for a coaxial gyrotron with one electron beam.
摘要:
In an inner conductor of a coaxial gyrotron, which inner conductor is disposed on the cathode of the gyrotron and includes an entrance funnel, a center part and an exit funnel, axial corrugations are formed in the conductor by axial grooves formed into its wall such that they begin at the end of the entrance funnel and have, in the center part, an increasing depths up to the exit funnel, in which the depth again becomes steadily smaller, the corrugations being evenly distributed about the inner circumference of the inner conductor.
摘要:
A gyrotron system comprises an electron gun that produces an electron beam, a magnetic field generating unit comprising a permanent magnet and two electromagnets and capable of generating an axial magnetic field that drives electrons emitted from the electron gun for revolving motion, a cavity resonator that causes cyclotron resonance maser interaction between the revolving electrons and a high-frequency electromagnetic field resonating in a natural mode, a collector for collecting the electron beam traveled through the cavity resonator, and an output window through which a high-frequency wave produced by the cyclotron resonance maser interaction propagates. The gyrotron system can be fabricated at a comparatively low cost, is easy to operate, has a comparatively small size and is capable of operating at a comparatively low running cost.
摘要:
A harmonic gyro-TWT is provided that has only one possible mode of operation. The harmonic gyro-TWT comprises a waveguide and an electron beam projected through the waveguide and encircling an axis of the waveguide. A plurality of evenly spaced electrical conductors are disposed within the waveguide parallel to the axis and spaced a fixed distance from an inner wall of the waveguide. The electrical conductors are connected together at an end of the waveguide. The electrical conductors are excited in phase with an AC signal connected between the electrical conductors and the inner wall of the waveguide. As a result, a multipole field having an order equal to twice the number of electrical conductors is defined within the waveguide. A plurality of support rails couple the inside surface of the waveguide to each respective one of the plurality of electrical conductors. The distance between adjacent ones of the support rails is approximately equal to 1/4 of a wavelength of a center frequency of a desired passband of the harmonic gyro-TWT, and the distance between the inner wall of the waveguide and the electrical conductors along a respective one of the support rails is approximately equal to 1/4 of a wavelength of a center frequency of a desired passband of the harmonic gyro-TWT.
摘要:
A quasi-optical component for microwave radiation comprises a quasi-optical element (16a) which radiates incident microwave radiation along a major axis (19) and which has a characteristic transverse dimension (D) which is smaller than 50-times one wavelength. It is distinguished by the fact that a cooled absorption device (17) is provided which is arranged closely in front of the quasi-optical element (16a) in such a manner that at least one high-power secondary peak (20) of the diffraction due to the characteristic transverse dimension is destroyed.
摘要:
In a quasi-optical gyrotron which exhibits a quasi-optical resonator having two mirrors (4a, 4b) which opposite one another on a resonator axis (5), the required electromagnetic radiation is coupled out by means of a hologram. In this arrangement, at least one of the two mirrors (4b) of the resonator exhibits a reflective surface (8b) provided with a hologram. The hologram is constructed in such a manner that the radiation to be coupled out is scattered in the direction of at least exactly one coupling-out axis (10), the at least exactly one coupling-out axis (10) enclosing a predetermined angle .alpha. not equal to zero with the resonator axis (5). The angle .alpha. is preferably as small as possible.
摘要:
A method and apparatus for suppressing lower order cyclotron harmonics in order to permit resonance within a quasi-optical gyrotron/gyroklystron configuration of a desired higher order harmonic. In the gyrotron/gyroklystron configuration at least one open resonator defined by at least two mirrors is positioned downstream from an electron beam source for receiving therethrough the beam of electrons and for exchanging energy therewith. This method includes the steps of choosing a mirror radius size .rho. for the mirrors forming the at least one open resonator which is large enough relative to the spot size of a desired radiation cyclotron harmonic .omega..sub.n so that the harmonic .omega..sub.n oscillates within the at least one resonator, but small enough so that the spot size for the next lower cyclotron harmonic .omega..sub.m is larger than the mirror so that the harmonic .omega..sub.m does not oscillate due to diffraction losses. This method further includes the step of generating an electron beam via the electron beam source with a beam current which is greater than or equal to the starting current I.sub.n for the desired nth cyclotron harmonic, but less than the starting current I.sub.m for the mth cyclotron harmonic. The method also includes the step of extracting radiation energy at the nth cyclotron harmonic from the at least one open resonator. The desired mirror radius size .rho. for a given cyclotron harmonic frequency .omega..sub.n, for a desired diffraction loss Y.sub.n for that harmonic n, a given half length separation L.sub.y between the mirrors, and a given radius of curvature R.sub.M, can be determined by the equation ##EQU1## wherein r.sub.on is the spot size at the mirror for radiation at the nth cyclotron harmonic.
摘要:
A gyrotron backward wave oscillator device is described which can be operated in a controlled and predictable manner. The device includes an evacuated waveguide section, an electron source at one end providing a spiral electron beam, a collector at the opposite end, means for producing a magnetic field parallel to the longitudinal axis of the waveguide section, and an output window, the parameters of the device being such as to support backward wave oscillation therein and to output same through the window.
摘要:
Disclosed are methods and devices suitable for generating electron beams and pulses of radiation. Specifically, in some disclosed embodiments, multiple emitting electrodes of a ferroelectric emitter are sequentially activated, generating a relatively long electron beam pulse that is substantially a series of substantially consecutive short electron beam pulses generated by the sequentially-activated individual emitting electrodes.