EHL-2 device model
Our next-generation device is a spherical torus called EHL-2. EHL stands for ENN He-Long, which literally means "Peaceful Chinese Loong." EHL-2 will play a crucial role in advancing the understanding of nuclear fusion and developing technologies necessary for future p-11B fusion reactors. Currently, EHL-2 is in the physics design stage. The construction of EHL-2 is estimated to be completed by mid-2027.
The EHL-2 experiment platform is expected to be a leading ST fusion device capable of achieving several critical objectives, including:
1.To identify, study, and solve the most significant scientific and technological challenges associated with the development of STPBF.
2.To verify the scientific feasibility of proton-boron fusion.
3.To provide a scientific and technological foundation for subsequent construction of larger platforms to verify the engineering feasibility of proton-boron fusion.
4.In particular, to elevate fusion reactivity and verify the ST energy confinement scaling law, particularly in high magnetic fields and high-temperature (low collisionality) pB plasmas.
EHL-2 physics design parameters
Based on 0-dimential system design and 1.5-dimentional transport modelling analyses, the main target parameters of EHL-2 have been basically determined, including the plasma major radius, R0, of 1.05 m, the aspect ratio, A, of 1.85, the maximum central toroidal magnetic field strength, B0, of 3 T, and the plasma toroidal current, Ip, of 3 MA. The main heating system will be the NBI ion heating at a total power of 17 MW. In addition, 6 MW of electron cyclotron resonance heating (ECRH) will serve as the main means of current localization drive and MHD instability control.
The physics design of EHL-2 is focused on addressing three main operating scenarios, i.e., 1) high ion temperature scenario, 2) high-performance steady-state scenario and 3) high triple product scenario. Each scenario will integrate solutions to different important issues, including equilibrium configuration, heating and current drive, confinement and transport, MHD instability, p-11B fusion reaction, plasma-wall interactions, etc.