Time and place: 2018.11.26, 14:30 pm, Wuhan National High Magnetic Field Center B206

Presenter:Olgerts Dumbrajs

Title:History and presentstate of gyrotrons

Abstract：

Gyrotron is well recognized as a promising high-power millimeter-wave and terahertz source. They are capable of providing hundreds of kilowatts of power at microwave and millimetric wavelengths. I will start the talk with an introduction to the electromagnetic spectrum and the operating principle of gyrotron oscillator. In the electron cyclotron maser (ECM), the effective frequency is directly related to the magnetic field, namely, the strength of the magnetic field determines the radiation frequency. So, in the next part, I will explain the magnetic field required for a gyrotronto generate higher frequency waves. In the second part, I will introduce the development path of gyrotron. The conventional gyrotron oscillator was first built and is now still widely used in different laboratories. The coaxial cavity gyrotrons show many advantages, but the technical complexity is increased. To achieve higher operating frequency at a given magnetic field, gyrotrons can operate at harmonics modes, with an increased risk of mode competition. The advantages and challenges of such types of gyrotron will be illustrated. In the last, I will present the present theoretical work on gyrotrons at University of Latvia.