China is advancing the “artificial sun project” to develop an almost infinite energy source. Chinese scientists working on this project have discovered a previously unknown method of plasma activity that may enable more reliable and efficient nuclear fusion energy production.
A breakthrough and demonstration of a new plasma operating scenario called Super I-Mode has been performed on an Experimental Advanced Superconducting Tokamak (EAST), according To Hefei Institutes of Physical Sciences, Chinese Academy of Sciences (CAS).
Hefei’s EAST reactor detected “Super I-mode” for the first time in December 2021 after a record 17-minute operation, mentioned SCMP. The results, which have been rigorously peer-reviewed, were published January 6, 2023, in the international journal Science Advances.
The new highly confining, self-regulating Super I mode embodies the machine’s progression and reliability and provides insights into how to keep the plasma working stably and for a long time.
The standard run, which used magnetic fields to heat a plasma-charged gas consisting of free-moving electrons and hydrogen ions to a temperature of 70 million °C, managed to capture high energy at the plasma edge and farther out in the plasma.
Additional testing revealed that the new mode has high potential for use in the International Experimental Thermonuclear Reactor (ITER), according to Chinese Academy of Sciences researchers and their collaborators from the United States, Europe and Japan, among others.
The world’s largest fusion reactor, ITER, is currently being built in France. This is a significant achievement for ITER and fusion, according to physicist Richard Bates, who oversees experiments and plasma operations at ITER.
Bates added that the EAST tests are important because they have revealed for the first time that tokamak plasma can be preserved and regulated for very long pulses — more than 1,000 seconds, which is equivalent to the long pulses for which ITER aims long term.
Bates noted several challenges associated with very long pulse operations, and it is very reassuring for ITER to see this accomplished, even on a much smaller device.
According to Song Yuntao, a co-author of the study, one of the main benefits of Super I-mode was its ability to reduce energy losses near the plasma edge, where the superheated gas directly encounters the tokamak’s heat shield.
If we equate nuclear fusion processes with lightning bolts, Song explained, the researchers aim to collect as many bolts as possible in a magnetic cage and transfer energy in a stable and sustainable way for human use.
The new operating mode discovered at EAST allows Chinese scientists to capture more lightning bolts while maintaining steady-state performance for an extended period, Song said.
Why is the new Super I-Mode important?
Fusion is the process of fusion of two hydrogen atoms to produce an atom of helium while emitting enormous energy, which powers the sun and stars.
Scientists aim to recreate the sun’s power on Earth and want to control the fusion process well. They expect society to be fed in a new, more efficient and environmentally friendly way.
one of the most promising methods Towards administered nuclear fusion with tokamaks such as EAST and ITER. The challenge remains producing high-performance plasmas and confining them long enough for hydrogen to combine to produce net energy as the sun does.
Liu Zhihong of the Institute of Plasma Physics in Hefei states that fusion scientists use operating parameters, or “modes,” to control the state of the plasma. These factors include temperature and energy.
Most Today’s tokamaks, including EAST, are operated in high confinement or H-mode. Large reactors such as ITER were made possible by H-mode, first discovered on a tokamak in Germany in 1982. H-mode was no less efficient than 100 times more plasma confinement than the previous low confinement mode.
However, a significant drawback of H-mode operation is that it may cause a sudden release of energy at the edge of the plasma and damage nearby materials.
To avoid damaging surfaces, scientists recently discovered mode I, also known as enhanced confinement mode, in which fusion energy is released through a more continuous process.
But the scientists were amazed to learn that when compared to I-mode, the new mode greatly enhanced energy trapping, earning it the nickname Super I-mode. Bates noted that because the super I mode was only observed on EAST, it is unclear whether ITER can use it. He added that ITER planned to operate in “advanced scenarios” similar to the East’s experiences.
“These advanced scenarios allow you to run very long periods of plasma — up to 3,000 seconds on ITER. In H mode, ITER can only spike for 500 seconds of plasma,” Bates said.
EAST is the first of its kind to operate with pulses of 1,000 or less. Since its commissioning in 2006, the reactor has supported thousands of experiments conducted both locally and with the global fusion community.