Human yearning for nuclear fusion is like Prometheus stealing skyfire in myth. This is not only because it can release huge energy, but also because it represents a clean, safe and almost unlimited energy prospect. At the core of the sun, a spectacular nuclear fusion feast is being staged at all times, which gathers hydrogen atoms into helium atoms and releases light and heat on which we live. What we are pursuing is to bring this "fire of the sun" to the earth.
To realize controlled nuclear fusion, we must first face two core challenges: high temperature and high pressure. In order to make positively charged nuclei overcome strong electrostatic repulsion, get close to each other and fuse, we must heat the plasma to hundreds of millions of degrees Celsius. This is an unimaginable high temperature, and no known material can directly contact and contain it. Therefore, scientists must find a way to suspend the plasma so that it does not touch the container wall. At present, the mainstream solution is to use a strong magnetic field to restrain the plasma, which is like using an invisible magnetic bottle to "catch" this hot substance. The representative of this technical route is the Tokamak and the Star Simulator.
Another key challenge is to maintain sufficient density and time. Nuclear fusion reaction requires a sufficient number of nuclei to remain in a high temperature and high pressure state for a long time, in order to produce a net energy output. This means that we can't just "light" it briefly, but make it like a burning stove. In recent years, with the continuous progress of technology, we have made breakthrough progress in plasma confinement time and temperature. Some experimental devices have been able to maintain the plasma for several minutes, and the temperature has reached the standard required for nuclear fusion.
However, we still have a long way to go to turn scientific breakthroughs in the laboratory into feasible commercial power generation. This is not only a technical problem, but also a comprehensive challenge of engineering, materials and economy. We need to develop new materials that can withstand high-energy neutron bombardment to build a durable reactor inner wall; We need to design an efficient system to convert the heat generated by nuclear fusion into electricity; We also need to find an economically feasible way to produce and maintain these complex equipment on a large scale.
Despite many challenges, scientists and engineers around the world have not stopped. We are moving from pure scientific exploration to engineering verification stage. Some private enterprises have also joined the "energy revolution", bringing new technical routes and flexible business models. They tried to accelerate the commercialization of nuclear fusion through more compact and more innovative design.
Predicting how long it will take to control nuclear fusion is as difficult as predicting when the next scientific and technological revolution will come. The optimistic view is that in the next decade or two, we are expected to see the first demonstration nuclear fusion power station that can produce net energy output; A more cautious view is that large-scale commercial power generation may take longer. But in any case, nuclear fusion as the ultimate energy dream of human society is no longer out of reach. The success of every experiment and the discovery of every new material bring us closer to this goal. We may not be able to calculate the exact year, but what is certain is that we are steadily moving towards this future.
