If you were to ask what the most challenging scientific research in the world is, according to Pan Yuan, an academician of the Chinese Academy of Engineering and a professor at Huazhong University of Science and Technology, there is no doubt it would be magnetic confinement nuclear fusion, also known as the "artificial sun." How to turn this "science fiction" into reality? He has been exploring this for many years.
Academician Pan Yuan. Image provided by the Hubei Provincial Department of Science and Technology.
Pursuing the "Artificial Sun"
This year, Academician Pan Yuan is already 90 years old. He told reporters that among all his scientific achievements, what makes him most proud and concerned is the "artificial sun." Scientifically speaking, it's called magnetic confinement nuclear fusion.
"Why is it called the 'artificial sun'? Because its purpose is energy, and nuclear fusion is about controlling hydrogen bombs to gradually release energy," Pan Yuan said.
Just how difficult is this project?
Pan Yuan explained that the occurrence of solar fusion is inseparable from the immense gravitational force of the sun. Under conditions of high temperature and pressure, hydrogen nuclei in the sun's interior, stripped of their electrons, collide due to mutual attraction, leading to fusion reactions. However, Earth's gravity is only one three-hundred-thousandth of that of the sun. Confining super-hot plasma on Earth to achieve controlled nuclear fusion is as challenging as the myth of "Kuafu chasing the sun."
As early as 1984, Pan Yuan participated in and completed China's first "artificial sun" device—the Chinese Tokamak Device-1.
At the outset of constructing the Chinese Tokamak Device-1, there was a severe lack of reference materials, with engineers having only a 4-page article introducing the general overview of similar devices from the former Soviet Union. As for how to design each component of the device specifically, it required their own exploration and experimentation.
"I drew the main wiring diagram and the logic diagram of the control system by myself. I was young at the time, and I would work until midnight. The device was very complex, with several sets of ultra-high vacuum and external power supplies. I would think, discuss, and revise repeatedly while drawing, ensuring that the dimensions of the device were stable in relation to the overall design," Pan Yuan recalled.
Additionally, there was a need to solve the issue of sourcing equipment. Pan Yuan collaborated with external factories for extensive equipment development. Among these, he is most proud of the two alternating current pulse generators he led the development of, which provided a powerful impetus for the development of nuclear fusion in China. These two 80-megawatt pulse generators were the largest in China at the time and are still in use today.
Overcoming numerous obstacles, Pan Yuan and his team finally succeeded in developing the Chinese Tokamak Device-1 on September 21, 1984. It marked the transition of China's controlled nuclear fusion research from theoretical exploration to large-scale physical experiments, providing an important experimental platform for China's nuclear fusion research and development and becoming a milestone in China's controlled nuclear fusion research and development.
After the successful development of Tokamak-1, nuclear fusion research has always been Pan Yuan's core work. In 2016, Pan Yuan further focused on fusion materials and identified deuterium as the key element, proposing a new technical path—deuterium-deuterium fusion.
Last November, the project "Pre-research on Magnetic Confinement Deuterium-Deuterium Fusion Neutron Source" was approved in Hubei Province's major science and technology infrastructure plan and commenced construction in the Optics Valley Science Island in Wuhan. Pan Yuan and his students will continue to explore around the project construction.
Exploring the Ultimate Energy
Pan Yuan's focus has always been on addressing national needs, with the goal of achieving superiority in people, strength, and innovation.
In addition to nuclear fusion energy, Pan Yuan is also committed to the construction of China's pulse strong magnetic field experimental device. At the end of the 20th century, Pan Yuan keenly noticed that since the discovery of high-temperature superconductors in the 1980s, Europe and the United States had successively built pulse strong magnetic field laboratories. He proposed the expedited construction of China's pulse strong magnetic field experimental device in 2001, which later became one of the 12 major science and technology infrastructure projects constructed in China during the Eleventh Five-Year Plan period.
To advance the project, Pan Yuan led the team to propose a dynamic control scheme for double-capacitor coupling, solving some technical challenges in the generation of flat-top magnetic fields during pulse generation, allowing China to take the lead in pulse strong magnetic field technology globally.
By the end of 2022, the facility had accumulated over 70,000 hours of operation, providing scientific research services for 1,677 domestic and foreign research units such as Peking University, Tsinghua University, and the Institute of Physics of the Chinese Academy of Sciences, and publishing 1,385 papers in journals such as Nature, Science, and PRL, achieving a large number of original results including the discovery of new types of quantum oscillations.
Pan Yuan subscribes to four newspapers year-round, seeking out problems that his professional background can solve within the context of national development.
To address the smog problem in the Beijing-Tianjin-Hebei region, he proposed the construction of a flexible DC power grid, providing high-quality environmental protection for the successful hosting of the 2022 Winter Olympics; to address the issue of heavy electricity loads in the southern power grid, he innovatively developed the world's first 500,000-volt mechanical DC circuit breaker, avoiding losses to the power grid infrastructure...
Currently, Pan Yuan's team is conducting experiments in the direction of instantaneous temperature rise and energy recovery, continuously exploring towards the direction of ultimate energy. Pan Yuan said that this is his swan song, and also the most difficult scientific research work in the world. He may not see the day when his swan song shines on the international stage, but as long as China can reach the top of relevant research through this, he will be happy.
