题 目：History and presentstate of gyrotrons

报告人：Olgerts Dumbrajs教授

        拉脱维亚大学物理学教授

        美国物理学会的终身会员

        欧洲ITER项目专家组成员

时 间：2018年11月26日（周一）下午14:30

地 点：国家脉冲强磁场科学中心B206

报告摘要：

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.

报告人简介：

Olgerts Dumbrajs教授是欧洲ITER专家组成员、美国物理学会终身会员、拉脱维亚荣誉科学家、拉脱维亚科学院院士、欧洲等离子体物理理论委员会成员。长期从事回旋管理论的研究，是回旋管领域的权威专家，日本福井大学THz中心和德国KIT回旋管研究中心客座教授、顾问专家。

热忱欢迎广大老师，同学来聆听讲座！