时间：周二，5月20日，14:00
地点：海纳苑8幢322教室
报告人：傅国勇教授
Since the beginning of the research on magnetic confinement fusion in early 1950s, many types of magnetic confinement plasma devices have been invented, such as the linear magnetic mirror, Z-Pinch, the toroidal tokamak and stellarator. The magnetic mirror is one of the earliest and simplest magnetic confinement devices. It utilizes a non-uniform magnetic field to confine plasma in a magnetic trap. However, it suffers from serious end losses which severely degrade particle and energy confinement. To address this issue of end losses, researchers have developed various solutions to reduce the end losses, including the tandem mirror approach using complicated end-plug coils. In this talk we present the proposal for a new approach to magnetic fusion: the linked mirror [Feng, Nuclear Fusion 2021, and Qiu et al. 2025]. In the early version, the linked mirror consists of two linear magnetic mirror sections connected with two half-torus solenoids. The two straight mirror sections are not parallel. The angle between them generates a finite rotational transform just like the early figure-8 stellarator invented by Lyman Spitzer in 1950’s. Particle simulation results show that this linked mirror scheme completely solves the problem of particle end losses of the linear magnetic mirrors, and the corresponding neoclassical transport is very small. In the new version of linked mirror obtained very recently, we use the 3D shape of the two half-torus solenoids to generate both rotational transform and magnetic well for particle confinement and MHD stability. Compared with tokamak and stellarator, the linked mirror approach has the advantages of simple structure, good confinement, and natural steady-state operation, and has potential for future fusion reactors.
