<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chao-Hai Du</style></author><author><style face="normal" font="default" size="100%">T. H. Chang*</style></author><author><style face="normal" font="default" size="100%">P. K. Liu*</style></author><author><style face="normal" font="default" size="100%">C. P. Yuan</style></author><author><style face="normal" font="default" size="100%">S. J. Yu</style></author><author><style face="normal" font="default" size="100%">G. F. Liu</style></author><author><style face="normal" font="default" size="100%">Vladimir L. Bratman</style></author><author><style face="normal" font="default" size="100%">Mikhail Yu. Glyavin</style></author><author><style face="normal" font="default" size="100%">Yu. K. Kalynov</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Development of a magnetic cusp gun for terahertz harmonic gyrodevices</style></title><secondary-title><style face="normal" font="default" size="100%">IEEE Transactions on Electron Devices</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6352876</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">59</style></volume><pages><style face="normal" font="default" size="100%">3635-3640</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span&gt;A magnetic cusp gun (MCG) is being developed to generate an axis-encircling electron beam, which is called the large orbit beam, which is going to drive a 0.396-THz fourth-harmonic gyrotron. Developing an MCG imposes crucial challenges on a simultaneously minimizing guiding center deviation and velocity spread of the electron beam, particularly because an ultrahigh magnetic compression ratio is unavoidable, as is the case for a terahertz (THz) gyrotron. The study of the electron dynamics in the MCG reveals that, close to the emitter, a pair of focusing electrodes are employed to construct a special focusing and accelerating electric field as a way to balance the space-charge influence and guiding center deviation. Investigation indicates that both the electron-beam generalized-angular-momentum spread and the guiding center distribution are the critical factors contributing to beam parameter spread. Intensive optimization generates a high-power MCG with a pitch factor of 1.5, the highest magnetic field of 4 T, minimum transverse velocity spread of 1.1%, and a beam current of 2 A. The key parameters exhibit excellent stability tuning over a wide range of beam current and magnetic field. These merits enable the harmonic gyrotrons or even the frequency-tunable THz gyrotrons to be developed.&lt;/span&gt;&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">12</style></issue></record></records></xml>