@inproceedings{oai:niigata-u.repo.nii.ac.jp:00031904, author = {Ogura, Kazuo and Ono, Atsushi and Watanabe, Osamu}, book = {平成10年度核融合科学研究所共同研究研究会「パルスパワー生成高温・高密度プラズマ物理とその応用」セッション4(16), 平成10年度核融合科学研究所共同研究研究会「パルスパワー生成高温・高密度プラズマ物理とその応用」セッション4(16)}, month = {Dec}, note = {A large diameter backward wave oscillator (BWO) without guiding magnetic field is demonstrated experimentally. The beam propagation is achieved by filling SWS with helium gas. The oscillation mode of the BWO might be the axisymmetric TM mode as well as TE mode. The output power of the TM mode is less than lkW, which corresponds to electronic efficiency less than 0.004 %. At zeo-magnetic field, the conventional Cherenkov and cyclotron interactions are degenerate and perturbed beam motions perpendicular as well as parallel to an axial direction should be taken into account. In the degenerate beam interaction, surface charge σ1 at beam-vacuum boundary plap essential role. Numerical analysis shows that the degenerate interaction is superior to the conventional Cherenkov interaction in the high current region above 100 A and in the weakly relativistic energy region., 本報告書は、大学共同利用機関法人自然科学研究機構核融合科学研究所からリポジトリ登録許諾を得て、平成9年度~平成11年度科学研究費補助金(基盤研究(C)(2))研究成果報告書(課題番号:09680456)「チェレンコフ・サイクロトロン縮重相互作用によるマイクロ波発生の研究」(小椋一夫著)から複製したものである。}, publisher = {核融合科学研究所}, title = {Study of a Large Diameter Backward Wave Oscillator without Guiding Magnetic Field}, year = {1998} }