It was clear that the Cherenkov radiation is result of the coupling between the slow TM mode propagated along the waveguide and the negative-energy space-charge mode propagated along the beam, and the coupling strength is proportional to the beam density.

• 分析结果表明:切伦科夫辐射是由沿介质同轴波导传播的慢波与沿薄环形相对论电子注传播的负能空间电荷波耦合所致,且其耦合强度与电子注的密度成正比;