And the merger?

Reports at the end of last year about the construction of a reactor for synthesis by Chinese specialists sounded sensational (1). China's state media reported that the HL-2M facility, located at a research center in Chengdu, will be operational in 2020. The tone of the media reports indicated that the issue of access to the inexhaustible energy of thermonuclear fusion was solved forever.

A closer look at the details helps to cool the optimism.

Nowy tokamak type apparatus, with a more advanced design than those known so far, should generate plasma with temperatures above 200 million degrees Celsius. This was announced in a press release by the head of the Southwestern Institute of Physics of the China National Nuclear Corporation Duan Xiuru. The device will provide technical support to the Chinese working on the project International Thermonuclear Experimental Reactor (ITER)as well as construction.

So I think it's not yet an energy revolution, even though it was created by the Chinese. reactor KhL-2M so far little is known. We do not know what the predicted thermal output of this reactor is or what levels of energy are needed to run a nuclear fusion reaction in it. We do not know the most important thing - is the Chinese fusion reactor a design with a positive energy balance, or is it just another experimental fusion reactor that allows a fusion reaction, but at the same time requires more energy for "ignition" than the energy that can be obtained as a result of reactions.

International effort

China, along with the European Union, the United States, India, Japan, South Korea and Russia, are members of the ITER program. This is the most expensive of the current international research projects funded by the above mentioned countries, costing around US$20 billion. It was opened as a result of cooperation between the governments of Mikhail Gorbachev and Ronald Reagan during the Cold War era, and many years later was included in a treaty signed by all these countries in 2006.

2. At the construction site of the ITER tokamak

The ITER project in Cadarache in southern France (2) is developing the world's largest tokamak, that is, a plasma chamber that must be tamed using a powerful magnetic field generated by electromagnets. This invention was developed by the Soviet Union in the 50s and 60s. Project Manager, Lavan Koblenz, announced that the organization should receive the "first plasma" by December 2025. ITER should support a thermonuclear reaction for about 1 thousand people each time. seconds, gaining strength 500-1100 MW. For comparison, the largest British tokamak to date, JET (joint European torus), retains a reaction for several tens of seconds and gains strength up to 16 MW. The energy in this reactor will be released in the form of heat - it is not supposed to be converted into electricity. Delivering fusion power to the grid is out of the question as the project is for research purposes only. It is only on the basis of ITER that the future generation of thermonuclear reactors will be built, reaching the power 3-4 thousand. MW.

The main reason why normal fusion power plants still do not exist (despite over sixty years of extensive and costly research) is the difficulty of controlling and "managing" the behavior of the plasma. However, years of experimentation have yielded many valuable discoveries, and today fusion energy seems closer than ever.

Add helium-3, stir and heat

ITER is the main focus of global fusion research, but many research centers, companies and military laboratories are also working on other fusion projects that deviate from the classical approach.

For example, conducted in recent years on from the Massachusetts Institute of Technology experiments with Helem-3 on the tokamak gave exciting results, including tenfold increase in energy plasma ion. Scientists conducting experiments on the C-Mod tokamak at the Massachusetts Institute of Technology, together with specialists from Belgium and the UK, have developed a new type of thermonuclear fuel containing three types of ions. Team Alcatel C-Mod (3) conducted a study back in September 2016, but the data from these experiments have only recently been analyzed, revealing a huge increase in plasma energy. The results were so encouraging that the scientists running the world's largest operating fusion laboratory, JET in the UK, decided to repeat the experiments. The same increase in energy was achieved. The results of the study are published in the journal Nature Physics.

3. Tokamak Alcator C-Mod in operation

The key to increasing the efficiency of nuclear fuel was the addition of trace amounts of helium-3, a stable isotope of helium, with one neutron instead of two. The nuclear fuel used in the Alcator C method previously contained only two types of ions, deuterium and hydrogen. Deuterium, a stable isotope of hydrogen with a neutron in its nucleus (as opposed to hydrogen without neutrons), makes up about 95% of the fuel. Scientists at the Plasma Research Center and the Massachusetts Institute of Technology (PSFC) used a process called RF heating. The antennas next to the tokamak use a specific radio frequency to excite the particles, and the waves are calibrated to "target" the hydrogen ions. Because hydrogen makes up a tiny fraction of the total density of the fuel, concentrating only a small fraction of the ions on heating allows extreme energy levels to be reached. Further, the stimulated hydrogen ions pass to the deuterium ions prevailing in the mixture, and the particles formed in this way enter the outer shell of the reactor, releasing heat.

The efficiency of this process increases when helium-3 ions are added to the mixture in an amount of less than 1%. By concentrating all the radio heating on a small amount of helium-3, the scientists raised the energy of the ions to megaelectronvolts (MeV).

First come - first served Equivalent in Russian: Eating late guest and bone

There have been many developments in the world of controlled fusion work over the past few years that have rekindled the hopes of scientists and all of us to finally reach the "Holy Grail" of energy.

Good signals include, among others, discoveries from the Princeton Plasma Physics Laboratory (PPPL) of the US Department of Energy (DOE). Radio waves have been used with great success to significantly reduce the so-called plasma perturbations, which can be crucial in the process of "dressing up" thermonuclear reactions. The same research team in March 2019 reported a lithium tokamak experiment in which the inner walls of the test reactor were coated with lithium, a material well known from batteries commonly used in electronics. The scientists noted that the lithium lining on the walls of the reactor absorbs scattered plasma particles, preventing them from being reflected back to the plasma cloud and interfering with thermonuclear reactions.

4. Visualization of the TAE Technologies project

Scholars from major reputable scientific institutions have even become cautious optimists in their pronouncements. Recently, there has also been a huge increase in interest in controlled fusion techniques in the private sector. In 2018, Lockheed Martin announced a plan to develop a compact fusion reactor (CFR) prototype within the next decade. If the technology the company is working on works, a truck-sized device will be able to provide enough electricity to meet the needs of a 100-square-foot device. city ​​dwellers.

Other companies and research centers are competing to see who can build the first real fusion reactor, including TAE Technologies and the Massachusetts Institute of Technology. Even Amazon's Jeff Bezos and Microsoft's Bill Gates have recently become involved in merger projects. NBC News recently counted seventeen small fusion-only companies in the US. Startups like General Fusion or Commonwealth Fusion Systems are focusing on smaller reactors based on innovative superconductors.

The concept of "cold fusion" and alternatives to large reactors, not only tokamaks, but also the so-called. stellarators, with a slightly different design, built including in Germany. The search for a different approach also continues. An example of this is a device called Z-pinch, built by scientists from the University of Washington and described in one of the latest issues of the journal Physics World. The Z-pinch works by trapping and compressing the plasma in a powerful magnetic field. In the experiment, it was possible to stabilize the plasma for 16 microseconds, and the fusion reaction went on for about a third of this time. The demonstration was supposed to show that small-scale synthesis is possible, although many scientists still have serious doubts about this.

In turn, thanks to the support of Google and other advanced technology investors, the California company TAE Technologies uses a different, than typical for fusion experiments, boron fuel mixture, which were used to develop smaller and cheaper reactors, initially for the purpose of the so-called fusion rocket engine. A prototype cylindrical fusion reactor (4) with counter beams (CBFR), which heats hydrogen gas to form two plasma rings. They combine with bundles of inert particles and are kept in such a state, which should contribute to an increase in the energy and durability of the plasma.

Another fusion startup General Fusion from the Canadian province of British Columbia enjoys the support of Jeff Bezos himself. Simply put, his concept is to inject hot plasma into a ball of liquid metal (a mixture of lithium and lead) inside a steel ball, after which the plasma is compressed by pistons, similar to a diesel engine. The pressure created should lead to fusion, which will release a huge amount of energy to power the turbines of a new type of power plant. Mike Delage, chief technology officer at General Fusion, says commercial nuclear fusion could debut in ten years.

5. Illustration from a US Navy thermonuclear patent.

Recently, the US Navy also filed a patent for a "plasma fusion device." The patent talks about magnetic fields to create "accelerated vibration" (5). The idea is to build fusion reactors small enough to be portable. Needless to say, this patent application was met with skepticism.