| The cyclotron autoresonance maser (CARM) amplifier has been demonstrated to be a high power, high gain coherent radiation source in millimeter and submillimeter waves. Potential applications include plasma heating, high-density communications, deep-space radar, high-gradient linear colliders, atmospheric sensing, and tracking of space debris.In the process of producing high power microwave, a large amount of Ohimc heating arised from short wavelength electromagnetic wave in cavity may harm the device stable operation; even induce that the device can not work normally. So, the thermal wall loading is one of the main technological constraints in the design of gyrotron cavity. One of available ways to reduce the wall loading is employing large diameter cavity which is with enlarged area to loss heating and is convenient for machining. However, most of operation modes in the large diameter cavity are high-order modes, which easy to make mode competition and unstable operation because of denser spectrum of high-order modes. It is confirmed in gyrotron oscillators that two ways to rarefy the operate modes' spectrums and enhance the beam-wave interaction are respectively using of coaxial cavity and slotted structure.Combining the characters of coaxial waveguide and slotted structure and advantages of high power and high efficient in CARM amplifier, slotted coaxial waveguide CARM amplifier have been proposed by Professor Zhang Shichang on the basis of proposed smooth coaxial waveguide CARM amplifier. It is reasonable in such device to rarefy the mode spectrum and depress the competing action of neighboring modes, enabling stable single mode operation and obtaining high power and ultrahigh gain.With the shape of the waveguide cross-section, there are four kinds of coaxial waveguide in this dissertation. They are smooth-coaxial waveguide, inner-slotted-coaxial waveguide, outer-slotted-coaxial waveguide, and outer-inner-slotted-...
|
PDF Full Text Request