Recently, the research team led by Prof. XU Guosheng from Institute of Plasma Physics, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences demonstrated a novel "two-step" magnet design strategy to design advanced stellarator with standardized permanent magnet blocks and simple coils.
The related achievement was published on Cell Reports Physical Science.
In the recent two years, permanent magnet was introduced to help simplify the complicated 3D coils of the stellarators and some designs have been proposed. However, the previous magnet designs are far away from engineering implementation due to the complicated forms of the permanent magnet blocks. Scientists have been considering to standardize the magnet blocks with regular shape and size, uniform magnetization and finite discrete magnetization orientations for mass production.
This "two-step" design strategy is proposed based on the "divide and conquer strategy" principle. It divided the design of large number of magnet blocks into independent designs of each magnet block. Thus, the standardized magnet blocks can be regularly customized for stellarator design. Moreover, the permanent blocks can be automatically arranged in Halbach arrays to obtain higher field strength.
Based on the new design strategy, scientists proposed identical cubic magnet blocks, which is the simplest form for mass production. The blocks were assembled like LEGO toys, which can improve assembly accuracy control and reduce the technical barrier for stellarator construction.
Compared with the previous designs, this new design significantly reduced the engineering difficulties and costs in design, construction, assembly and maintenance of the stellarator, which is important for future stellarator development.
Figure 1. Quasi-axisymmetric stellarator designed with identical cubic permanent magnet blocks and planar coils (Image by LU Zhiyuan)