ELECTRON DYNAMICS IN A CUSPED MAGNETIC FIELD

• Main Authors: CHIN-SHIH CHEN, 陳靜詩
• Other Authors: 程光蛟
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/30623601352092994353

碩士 === 國立海洋大學 === 電機工程學系 === 90 === Because of the fast rapid development of high-frequency microwave devices in the past half century, lots of high-frequency and high-power microwave power tubes were generated. Especially Gyrotrons, on which much study has been focused in recent years. Gyrotrons utilizes the cusp-magnetic field and large-orbit axis-encircling motion. This kind of magnetic field turns the motion of high-energy axis-accelerating electron beams into an axis-encircling one and makes it closer to the wall of the wave guide for better energy resonance interaction with the high-order harmonic waves. The advantages are a) the magnitude of magnetic field is inversely proportional to the N harmonic wave, b) size reduction of gyrotron, c) the energy of electron beams is directly proportional to the radius of the electron and d) enlarged moving path increases the relativistic effect to make the unstable effect of negative mass for better transition and radiation of high-frequency microwave. On the basis of basic physical principles, the dynamic mechanism of a single electron was studied in this thesis to understand the changes of electron trajectories by numerical simulation. The Runge-Kutta method was used to resolve these dynamic equations (six first-order differential equations for describing velocity and position). After establishing the model of computer simulation, many initial parameters will be changed and the results will be analyzed and discussed.