There has always been a famous joke in tech circles that if you ask a scientist at any time when controlled fusion will be achieved, the answer is always: "30 years away". The answer is always: "In 30 years". The joke is more of a regret than a tease.

There are always twists and turns in scientific progress, but there is no other industry that has brought us as much hope and disappointment as controlled fusion, and after more than half a century of "jumping the gun", is still being talked about. The reason why it holds so much promise for mankind is that controlled fusion has many advantages, such as almost unlimited storage capacity and zero-carbon, and is seen as the "ultimate solution" to all energy problems. 

Although still a long way from being practical, in the eyes of the industry, controlled fusion technology has not only not stagnated in recent years, but has been making a welcome, if not spectacular, progress.

To give an example from the national team.

In 2018, China's "artificial sun" EAST achieved 100 million degrees Celsius electron temperature for the first time, reaching the target temperature for nuclear fusion reactions. In 2020, EAST successfully operated at 100 million degrees Celsius for 20 seconds; in 2021, EAST achieved repeatable 120 million degrees Celsius for 101 seconds and 160 million degrees Celsius for 20 seconds of sustained operation, extending the time by a factor of five while setting a new world record. 

In Dangerous Peak's view, controlled fusion has completed the most difficult scientific breakthrough from 0 to 1, and we are actually on the eve of the ultimate energy transformation: as the ultimate energy source for the future of mankind, "controlled fusion" is a typical "success gain far outweighs failure loss", and is naturally suitable for venture capital participation. With advances in high-temperature superconducting materials and reactor architectures over the last decade, the most difficult phase of controlled fusion has passed and the certainty of commercialization has increased dramatically. 

The trend towards compactness and miniaturization of fusion devices in recent years has opened up the possibility for commercial capital to enter. In particular, since 2020, global commercial capital investment in controlled fusion is picking up speed to the naked eye, signaling that the battle for the ultimate energy source may be about to enter the final round and that Chinese technology entrepreneurs are not, and cannot, afford to be absent.

In this article, we will try to explore the opportunities, challenges, and investment opportunities in this track through the underlying technologies and key breakthroughs in the development of controlled fusion. We also hope that you will continue to follow Dangerous Peak and continue to learn with us.

Nuclear Fusion: the Ultimate Solution for Human Energy?

It all started when a Swiss patent office employee called Albert Einstein wrote down the famous formula on his desk one day while groping for fish: E=MC²

It was probably the most awesome descending blow in the entire history of 20th-century science - you know at the time physicists were reeling in Newton's system of conservation of energy, but Einstein came along and told everyone.

Energy is mass, mass is energy, it's all the same thing.

Such an astonishing "four by two" principle not only shocked academic circles but also immediately alerted the world to a huge opportunity. In other words, Einstein predicted the fact that any small loss of mass in the matter would release a tremendous amount of energy.

And humans couldn't wait to get their hands on that energy.

And so, naturally, the academic world was divided into two schools of thought around how to make the loss of mass occur. One school of thought was that a large atom could be split into two smaller atoms, which is called 'nuclear fission; so the Hiroshima bomb went off with a bang and mankind entered the nuclear age. Another idea was to compress two small atoms into one large atom, known as 'nuclear fusion, which was first demonstrated in 1933 when the British used a particle accelerator to bombard the isotope of hydrogen, deuterium.

Encouraged, scientists continued to work hard, and in 1952 they finally succeeded in achieving the first 'large-scale application' of nuclear fusion - the detonation of the world's first hydrogen bomb. The light of victory seemed to be beckoning to mankind.

Indeed, the optimism of the time was justified by the fact that nuclear fusion had three obvious and enormous benefits over nuclear fission: firstly, it was 'extremely efficient. Nuclear fusion is the highest energy known to be produced on earth, several orders of magnitude higher than nuclear fission. For example, 100 kilograms of fusion fuel can produce about as much energy as 5 tons of fission fuel or 350,000 tons of coal. The second is the 'almost unlimited supply of raw materials. 

The earth's surface is 70% ocean, and there is enough deuterium in seawater to fuel fusion for billions of years. Thirdly, it is "safe and environmentally friendly". The reason why the public is 'scared of nuclear talk' is that heavy atoms such as uranium and plutonium decay in the natural environment, releasing energy and radioactivity, and requiring artificial control of the reaction rate. 

In other words, nuclear fission reactions are 'easy to start but hard to stop' and can lead to major accidents like Chornobyl if care is not taken; whereas nuclear fusion is the opposite: it is 'hard to start but easy to stop' and if any of the conditions are not met, no fusion reaction will take place. If any one of these conditions is not met, the fusion reaction will not take place. In addition, nuclear fusion is based on the same principle as the sun, so there is almost no pollution and no carbon emissions, which can fundamentally solve mankind's energy problems.

Uncontrollable Nuclear Fusion

The ideal is rich, but the reality is bleak. Mankind lit up the fusion tree 70 years ago, but to this day, the word "controllable" has not yet been achieved. The reason why this is so difficult is that in order for two small atoms to collide and produce a large atom, three conditions must be met at the same time.

1. the temperature is high enough (to simulate an environment similar to that of the interior of the sun, so that the atoms reach a plasma state)

2. high enough density (so that they can collide together)

3. long enough to last (enough collisions)

Together, these three elements are known as the 'Lawson criterion', and one cannot be missing.

So the first problem was - where to find such a container that would hold all this hot plasma and not 'melt' itself?

It was the Soviets who finally came up with a solution: a magnetic field. Thus a Tokamak device, similar to a doughnut, was invented.

(Diagram: Tokamak device diagram)

The principle is simple: an electromagnet is energized to keep a stream of hot deuterium-tritium ions suspended in the air and then 'circled' along a central ring. This is like a giant 'washing machine' - a virtual 'drum' of hot ions spinning around, colliding with each other, and triggering fusion reactions.

In this way, the greatest contribution of the tokamak device to mankind was to turn the 'physics problem' of nuclear fusion into an 'engineering problem'.

Since then, the 'Lawson criterion' has also been translated into three very specific indicators: confinement, magnetic field strength, and device size. Theoretically, it was only a matter of improving materials, structures, and processes to improve the performance of these three metrics.

Why Now: What Advances Have Been Made in the Underlying Technology?

Increasing size has always been the simplest and most brutal approach compared to the other two metrics, which is why early fusion devices were so large.

But the problem with this is the high cost.

For example, the world's largest fusion reactor, ITER, located in France, is today 30 meters high and covers 180 hectares.

The capital investment of hundreds of billions of dollars and the decades-long construction cycle is clearly not conducive to rapid technology iteration and commercial operation. So in recent years, the idea of breaking the mold has reverted to improving 'constraint' and 'magnetic field strength'.

In fact, both electrifying an electromagnet and heating an atom to an ionic state require huge amounts of energy in themselves. A reactor only makes economic sense if it achieves "energy output > energy input", and the ratio of these two is known as the "Q-value".

Unfortunately, the best result in the industry so far has been achieved by JET in the UK, with a Q-value of only 0.67.

In other words, until today, no country or team has actually achieved a 'positive output' of fusion energy (i.e. Q>1); this has been one of the main points of criticism of controlled fusion over the years.

But to follow this logic in reverse - to commercialize fusion energy is actually quite simple - all that is needed is to bring down the cost of two pieces: one is the magnetic field and the other is heating.

Fortunately, thanks to the efforts of scientists, considerable progress has now been made in both of these areas, the most representative of which was the breakthrough in 'high-temperature superconductivity technology' around 2010.

One important reason for the low efficiency of the magnetic field in early reactors was that the magnetic coils at the time were all made of copper. To ensure the current density and magnetic field strength, they had to be wound very thickly, and as a result, they took up a lot of space, and most of the energy was wasted by converting it into heat, which could even burn up the coils over long periods of operation.

In recent years, however, with the application of new materials represented by YBCO, new generations of fusion devices have generally started to be equipped with more advanced high-temperature superconducting coils; these coils have zero resistance and little or no loss in the current passage, thus greatly improving the Q-value.

On the other hand, superconducting materials have also contributed to improvements in the 'form factor' of tokamaks.

The design of the tokamak itself has been responsible for the slow progress in controlled fusion research in the past.

"The 'doughnut' structure, although classical, is very difficult to control because the magnetic field and ion flow profiles are extremely irregular - the closer to the outer edges, the weaker the confinement.

Therefore, if we consider 'confinement' alone, the 'spherical tokamak' is actually far superior to conventional tokamak designs.

(Chart: Spherical tokamaks are better constrained than rings; source: Star Ring Fusion)

The biggest problem with the spherical design, however, is that the space in the 'central column' is simply too small to accommodate the coils and neutron shield, and so it was kept on the back burner by the industry for many years until superconducting materials technology changed the game after 2010.

Tests have shown that high-temperature superconducting materials still have a very, very substantial critical current density at 25T magnetic fields - meaning that superconducting coils can be made small enough to fit into an intermediate column at the same magnetic field strength.

In other words, a fusion reactor with superconducting materials + a spherical design would theoretically require very little energy to achieve better confinement performance than in the past, which provides room for further increases in Q.

Currently, the fastest runner in this field is the British technology company Tokamak Energy (Tokamak Energy).

Back in 2017, Tokamak Energy built the world's first spherical tokamak reactor and this year achieved a reaction temperature threshold of 100 million degrees Celsius (i.e. the central temperature of the sun), setting a milestone in privately funded fusion research, for a total cost of just £50 million for the entire project.

Are We on the Eve of the Ultimate Energy Source?

According to a report published in 2021 by the Fusion Industry Association (FIA) and the UK Atomic Energy Authority, there are already more than 30 private technology companies working on fusion technology worldwide; of these, 18 companies with publicly available funding have received more than $2.4 billion in investment, almost all of which has come from commercial capital.

However, this figure may already be lagging behind the real response of the capital markets. Shortly after the report was released, US fusion start-up CFS (Commonwealth Fusion Systems) announced the completion of a $1.8 billion Series B round of funding.

This is the largest single funding round in the fusion sector to date, with investors from Bill Gates, Soros, Tiger Global Fund, Google's parent company Alphabet, Marc Benioff, DFJ Growth, and a host of other financial giants.

It is important to know that CFS was only founded in 2017 as a student project off the back of MIT - when a few MIT students were inspired by Iron Man's chest power core and came up with the idea of creating a minimized fusion product.

As one of the highest halls of physics, MIT has always had strong technological accumulation in magnetic confinement, and after several years of research, the CFS successfully leveraged high-temperature superconductivity to increase the magnetic field strength of fusion reactions by a factor of several dozen.

In September 2021, the CFS research team managed to achieve a magnetic field strength of 20 Tesla (T) by slowly charging a 10-tonne D-shaped magnet.

Remember that 'Lawson criterion' from earlier? The three elements that produce fusion: confinement properties, magnetic field strength, and size - three can be approximated as a multiplicative relationship.

For example, for every 1-fold increase in magnetic field strength for the same output power, the requirement for ion flow volume can be reduced by a factor of 16.

In other words, the increase in magnetic field strength and confinement means that the new generation of reactors can be made smaller, or the temperature does not need to be as high (100 million degrees is sufficient).

In any case, either way, it means an exponential drop in reactor construction costs, which provides room for commercial capital to enter.

For example, the prestigious science journal Nature published a long article in November 2021 called "Fusion energy may be just around the corner" about the fierce competition that is currently taking place between more than 30 technology companies around the world - to see who can be the first company in history to commercialize controlled fusion.

In addition, this year's MIT Technology Review's "Top 10 Breakthrough Technologies in the World 2022" lists "practical fusion reactors" alongside "grid storage batteries" and "carbon capture plants" - for which "achievable time", the article gives a judgment of fewer than 10 years.