**Acknowledgements**

The authors are thankful to Dr. M.V. Kartikeyan, professor, Indian Institute of Technology (IIT)-Tirupati, India, for his valuable suggestions and inputs. The authors are also thankful to Sri G. Viswam, Center Head, Microwave Tube Research & Development Center (MTRDC), Bangalore, India, for his necessary help and support. Also, the authors are thankful to Shroyonaa Karmakar, Jain University School of Design, for the preparation of the diagrams.

*Gyrotron: The Most Suitable Millimeter-Wave Source for Heating of Plasma in Tokamak DOI: http://dx.doi.org/10.5772/intechopen.98857*
