Minimization of effects of backscattered electrons in gyrotrons with depressed collectors

Gyrotron performance can be adversely affected by electrons backscattered from the collector and travelling back to the rf cavity and beyond. They can cause deposition of excessive heat in sensitive areas, and enter high field cavities, causing breakdown or instabilities. They can also become trapped, resulting in loss of mode purity. Avoiding such effects can enhance the reliability, usability and life of the gyrotron. Tailoring of magnetic field configuration offers a possibility of minimizing these adverse effects. A study of this approach is presented here.