模式纯度 meaning in English

mode purity

Output window is the core of the gyrotron , which speciality can decide the speciality of the gyrotron greatly . the major subjects of output window design for high power gyrotron are to reduce the reflection and absorption power in order to enhance the gyrotron ’ s stability and protect the output window
如果窗片的反射升高,在高功率情况下返回到高频系统的功率将显著上升,引起寄生模式在高频系统中自激振荡,从而降低回旋管的高频输出功率和模式纯度,乃至于使回旋管不能正常稳定工作。