China's "artificial sun" has made a new breakthrough.

On the afternoon of March 28, China National Nuclear Corporation announced that a breakthrough was made in the experiment of the new generation of artificial sun "China Circulation No. 3" (HL-3), and the nuclear temperature was 117 million degrees and the electron temperature was 160 million degrees for the first time in China.

"Our experiments have achieved 'double 100 million degrees', and the comprehensive parameters have also jumped significantly, marking the advancement of China's nuclear fusion research in combustion experiments." According to CCTV News, Zhong Wulu, the chief designer of CNNC's "China Gyre-3", said.

After the above news was announced, the A-share controllable nuclear fusion sector rose. As of the close of the day, Heduan Intelligent (603011.SH) and Snowman (002639.SZ) rose by the limit, Hongxun Technology (603015.SH) rose 5.61%, Guoguang Electric (688776.SH) rose 3.65%, and China Nuclear Construction (601611.SH) rose 2.38%.

A new generation of artificial sun, China Circulation-3 (HL-3), image source: China National Nuclear Corporation

"The so-called entry into the combustion experiment is to reach the threshold of 100 million degrees. But it's unclear whether HL-3 heats electrons and ions to 100 million degrees at the same time, or does it alone. A person in the domestic fusion industry told Jiemian News that if it reaches 100 million degrees at the same time, it will be a very big experimental breakthrough.

The person told Jiemian News that there are differences in the temperature of electrons and ions, and the heating methods are also different, and there is no device in China that can heat the two to more than 100 million degrees at the same time.

Nuclear fusion is the process by which light atomic nuclei combine into heavier nuclei and release enormous amounts of energy. Due to the relatively abundant raw material resources of fusion and no polluting emissions, controllable nuclear fusion has always been regarded as an important way out for mankind to solve the energy problem and is regarded as the "ultimate energy".

In the various nuclear fusion technology routes, Tokmak is known as the "artificial sun", and the center of its device is a ring-shaped vacuum chamber, with coils wound around the outside, like a doughnut, and when the power is applied, a huge spiral magnetic field is generated inside, and the plasma in it is heated to a very high temperature.

Plasma refers to the state of matter in which electrons detach from the nucleus at high temperatures to form free electrons and ions.

"China Circulation-3" is China's largest and most advanced tokamak device, which is independently designed and built by the Southwest Institute of Physics of Nuclear Industry of China National Nuclear Corporation, and its coil system is wound by copper conductor water-cooled coils.

In October 2022, the plasma current of "China Circulation No. 3" exceeded 1 million amperes, and in August 2023, it achieved high-confinement mode operation at 1 million amperes plasma current for the first time.

China National Nuclear Corporation said that the "China Circulation-3" experiment has achieved a significant jump in the comprehensive parameter fusion triple product.

The

fusion triple product (the product of plasma temperature, density, and energy confinement time) is a measure of the effect of fusion. It is believed that when this value reaches the 22nd power of 10, the power output of the fusion reaction can be greater than or equal to the power input to drive the reaction, and the ignition condition (Q>1) can be reached.

Because it is difficult for the pressure inside the Sun to form on Earth, fusion devices need to heat the plasma to more than 100 million degrees Celsius and maintain it long enough to trigger the fusion reaction.

Successful ignition also means that the "furnace" of the fusion raw material is ignited, and the plasma enters a self-sustaining combustion state, that is, no additional energy input from the outside is required, and an extremely high temperature can be maintained only by internal heating.

According to the above-mentioned domestic fusion industry sources, China's fully superconducting tokamak nuclear fusion (EAST) experimental device in Hefei, Anhui Province, has achieved plasma operation of more than 100 million degrees many times, but not the electrons and atomic nuclei have reached 100 million degrees at the same time.

The device was independently developed by the Hefei Institute of Physical Sciences of the Chinese Academy of Sciences, completed on September 28, 2006, and the first plasma discharge was successful, and the plasma has been operated more than 150,000 times so far.

In May 2021, EAST successfully achieved repeatable plasma runs of 120 million degrees Celsius for 101 seconds and 160 million degrees Celsius for 20 seconds. In December of that year, the device maintained a long-pulsed, high-parameter plasma with an electron temperature of nearly 70 million degrees Celsius for 1,056 seconds.

At the same time, the person pointed out that the European Joint Ring Facility (JET) in the United Kingdom, and the JT-60SA, a large-scale nuclear fusion experimental device jointly built by Japan and the European Union, have achieved simultaneous heating of electrons and ions to 100 million degrees.

The breakthrough of "China Circulation-3" is the embodiment of the core link of controlled nuclear fusion application, but it does not mean that fusion reaction will be realized soon.

On February 28 this year, Duan Xuru, a member of the National Committee of the Chinese People's Political Consultative Conference (CPPCC) and chief scientist of the fusion field of China National Nuclear Corporation, said at a meeting with representatives and members of the two sessions that the "China Circulation-3" is still in the experimental research stage, and the goal is to verify the feasibility of fusion reactor physics and engineering-related technologies, and it is not yet direct power generation.

Duan Xuru pointed out that the core task of the device is to achieve "fusion ignition", according to China's nuclear energy development strategy, its application is expected to be realized by the middle of this century (about 2050), is expected to enter the demonstration stage around 2045, and is expected to be commercialized around 2050.

However, the latest experiment of "China Gyre-3" has set a number of new records and achievements in China's fusion research.

"Our self-developed heating, control and diagnostic equipment and systems have been put into operation for the first time, and the relevant technical indicators have reached the forefront of the world, creating a number of new records in China's nuclear fusion research." Zhong Wulu said.

Among them, the self-developed high-power microwave cyclotron was successfully put into operation, with a maximum injection power of 2.5MW, and the control technology of stably obtaining the internal transport barrier of electrons was mastered, and the electronic temperature was 160 million degrees.

In addition, two sets of high-power neutral beam injection heating systems with completely independent intellectual property rights have been built and put into operation, with a maximum power of 7 MW per beam line, ranking among the first echelon in the world. This system is the core device for raising the temperature of the nucleus.

The Southwest Institute of Physics of the Nuclear Industry has also proposed and implemented a new method to improve the energy constraint of the core for the first time, and mastered the operation strategy of increasing the temperature of the atomic nucleus. According to the core energy constraint control method, the instability of the core magnetofluid, which restricts the increase of nuclear temperature, was successfully suppressed, and the technical problems such as current profile and density profile control were overcome, and the repeatable discharge of the nuclear temperature exceeding 100 million degrees was realized for the first time in China.