This article addresses how Fusion reactors will help achieve a Future of abundance and space exploration. We then explore methods to achieve Fusion reactions. We also deep dive into Magnetic Confinement reactors, their Anatomy, and the science behind them. Finally, we address some needed developments that will allow Fusion energy to reach its highest potential, jump-start our Type I civilization Status in the Galaxy.
Fusion reactors will eventually power our cities, spaceships, and colonies in this solar system and beyond. Clean fusion power will allow humanity to inhabit our solar system and expand further, sustainably. Fusion reactors are the ultimate positive net gain energy generators that produce environmentally friendly energy. It is the energy generator equivalent to replicators (Trekkie shoutout), a game-changer that will allow us to get closer to becoming a Type I civilization (TIC).
Let’s unpack that, shall we? There are many ways we can achieve TIC; we could stay earthbound, produce, and exhaust our resources to consume the equivalent of all the solar energy that hits our planet. Or we could colonize our solar system. The sum of our consumption throughout our colonies would be equal to the power threshold to qualify as a Type I civilization. Either way, Fusion power will play a significant role along those paths.
Fusion reactors will be able to generate an abundant amount of power. The game-changer here is that fusion reactors will have a positive net gain, meaning they will produce more energy than it takes to run them. We are currently halfway through building the Iter Fusion Reactor in the south of France that, when completely functional ( around 2035), will produce 500 Mega Watts (MW) of energy for every 50MW injected heat power; that is a ten-fold gain( Q= 10).
To achieve a Segan-Kardeschieve type 1.0 civilization, which requires 40 million gigawatts, we need to be producing enough energy to sustain 33.3 Thousand Chinas simultaneously (Chinas consumption in 2025 estimated around 1.2 thousand GW).
Iter is only a demo for future more efficient fusion reactors. The fuel to power the reactor is Hydrogen, abundant on earth and elsewhere in the solar system. Fusion is clean energy; unlike nuclear power plants, Fusion reactors do not produce radioactive waste, nor do they produce greenhouse gasses. Another factor is size. A current Reactor as big as a four-story building would produce 2 gigawatts (GW) more than what the Hover Dam currently provides ( 1.7 GW). With the advent of technology and material science, the reactors’ size will become smaller but still perform at high output.
With that said, we would not need coal and petroleum to power our cities. Our planet’s ecology will flourish again. We would be able to power Megastructures and Mega-cities on and of earth. Fusion reactors will power our space ships, orbital stations, and colonies on Mars, the moon, and elsewhere in our solar system. Abundant cheap and clean Fusion power will exponentially help us mine asteroids for raw material and have space manufacturing Gegafatories. Build bigger space ships that could travel faster and longer, bigger space stations that could launch exploration and science missions. Build and sustain planetary colonizations across plants and solar systems. Science fiction will become science fact.
Now, let’s break down the what and how of Fusion reactors.
Fusion Reaction Methods
Fusion reaction happens when two atoms fuse to produce a higher density atom. In the process, an enormous amount of heat is generated. The most common method to achieve a fusion reaction is confinement; Confinement produces high pressure, increasing the temperature of the plasma enough for the atoms to fuse. There are several types of confinement methods.
There is gravitational confinement; this method occurs naturally in stars. The mass and density of a star generate gravity; This pulls and confines the star’s mass into higher densities as we get closer to the star’s center. At a certain point relative to the center of a sun, the temperature becomes high enough to allow for a fusion reaction, turning, for instance, Hydrogen to Helium, Helium to Beryllium, Beryllium and Helium into Carbon and so forth.
Another type of confinement method is Magnetic confinement. Achieving Fusion in this type of confinement method is achieved by heating a gas and confining it within a strong magnetic field. This process turns the gas into a stable plasma flow, which produces heat to generate power.
Inertial confinement is another method of achieving a fusion reaction. In this method, multiple high energy laser ion beams to target a fuel pallet increasing its density and raising its temperature to generate a heat shock wave that would heat the gas into plasma. The heat from the plasma creates power.
Electrostatic confinement is a fourth type of fusion reaction generating confinement method. This confinement method uses electric fields to confine the plasma, unlike the magnetic confinement method that uses magnetic fields.
Gravitation Reactors: Our sun is a gravitation Fusion reactor. Unless we build a reactor that can harness the mass of stars, or physically tap into the energy of our sun, or prove and utilize the properties of the theoretical particle Graviton (different from the Marvel fictional Gravitonium), then a gravitational reactor is out of the question for the time being.
But wait, Graviton? Einstein’s general theory of relativity defines gravity as a warp in time and space caused by the mass of an astronomical object creating a dent on the space-time field. Now quantum mechanics theorizes that there should exist a theoretical particle, Graviton, emitted by the object that induces space-time to bend. The two physics above as they are now, are not unified. Each defines gravity differently according to in which realm we are observing it, the large or the small. Super String theory is a hypothetical framework unifying the physics of the large and the small into one theory of everything . The Super String theory has shown that it could produce a consistent theory of Graviton’s interactions. If Graviton’s theory is right and can be proven and eventually tested in experiments. The applications will change our entire world as we know it. We will deep dive into the science and implications of Graviton in a subsequent article.
For now, we have to work with what we have, which is still exciting and revolutionary. Innovative, dedicated scientists and engineers have been working on several types of reactors correlating to the different fusion reaction methods mentioned earlier. The Inertial Confinement Fusion (IFC) devices like the Lased Based National Ignition Facility Device(NIF), the Electrostatic Fusion Devices like the Fusor, and the most promising Magnetic Confinement reactors like the Sphere Torus Tokamak and the Stellarator. Let’s take a closer look at the most popular, available, and promising source of fusion energy, the Sphere Torus (ST) Magnetic Confinement reactor (MCR).
Magnetic Confinement Reactor (MCR)
The ST MCR works as follows. Gas is Ionized, heated up, accelerated, and injected into the reactor’s Torus section as plasma. A magnetic field then holds the plasma in confinement. Once the Magnetic confinement, it is further heated up to the point that allows for the fusion reaction. The atoms within the plasma fuse to become a higher element, and as a result, it produces Heat. The Heat runs a traditional generator that produces electricity.
A successful MCR would generate five times more power that is required to operate it (Q=5). Testes now can achieve Q=1.5; eventually, scientists and engineers expect the next generation MCR to have positive net energy of Q=10.
The most promising of the standard torus reactors is the Spherical Torus (ST) reactor. The Iter project in Europe is an excellent example of the innovation and development of an ST MCR.
The gas used as fuel in the MCR is Hydrogen: hydrogen isotopes to be more specific, Deuterium and Tritium. Hydrogen Isotope Deuterium (Heavy Water) is most efficient for fusion reactions. It is abundant in nature ( seawater); every cubic of seawater has an equivalent energy generation from Deuterium equals to +- 2 Kiloton bomb. In other words, there is a billion times abundance of Deuterium as a fuel in earth’s oceans than the reserves of Fussel fuel. Tritium, on the other hand, is scarce, but the fusion reactor produces Tritium as a byproduct, which we will discuss down the line.
The core fusion process starts with the Neutral Beam Injector.
Neutral Beam (NB) Injector
The NB function is to transmute the fuel gas to plasma and inject it into the reactor core. The process starts by injecting the hydrogen isotopes into the NB’s vacuum chamber. The isotopes pass through a high electric current, which strips the gas’s electrons, and the gas becomes positively charged. The positively charged hydrogen isotopes (ionized gas) then pass through an accelerating mesh grid, accelerating the gas flow within the NB. The accelerated ionized gas then passes through the “charge exchange” part of the NB, where a neutralizing gas is injected, neutralizing the Hydrogen gas. Neutralizing the heated and accelerated Hydrogen is an essential phase because only Neutral particles could penetrate the Electromagnetic field, holding the plasma in the ST vacuum Chamber. The last part of the NB is the Ion dump.
The Ion dump sucks in any remaining positively charged gas particles in the Hydrogen stream now Plasma stream. That way, only neutral gas plasma leaves the NB and is injected into the Torus vacuum chamber. By this time, the plasma has a temperature of 100 million degrees Celsius.
Anatomy of the Spherical Torus
The Tokamak’s spherical torus has two sets of Magnet systems, the Poloidal and the Toroidal, located around and encompassing the ST chamber. The Poloidal and the Toroidal Magnets are, in fact, electromagnetic coils. The next-generation Magnets for the ST-MCR will be made of HTC coils – high-temperature superconductor Coils.
These HTC coils are revolutionary because they operate most efficiently at very low temperatures, 20Kelvin (-253,15 Degrees Celsius), while withstanding very high loads of Amperes of electricity with zero resistance. That means no loss of energy that would otherwise transform into heat due to resistance (Friction). However, for the Electromagnetic coils to operate at full efficiency and act as superconductor Magnets, a cooling system cools the coils to near absolute zero (20Kelvin). The cooling system also acts as a temperature buffer protecting the Takoma from the plasma’s radiated heat. As a result, the HTC magnetic coils will generate a magnetic field intensity of 20 Tesla.
Tesla is the unit measuring the magnetic field intensity; in other words, the magnetic field’s strength. The HTC magnets will allow for 20 Tesla a fourfold increase. 20 Tesla is impressive, get this, the fridge magnet has 0.005 Tesla, and a white dwarf star has a magnetic field strength of 100 Tesla
The toroidal field coils in the ST-MCR create a magnetic field that acts on the plasma to generate a plasma current within the ST and confine it within the vacuum chamber center. The Poloidal Field coils, on the other hand, create a poloidal magnetic field that spins the plasma current, causing the plasma to move in a helical path within the chamber. Just like steering water with a spoon in a heating pot, the plasma’s spiraling current ensures the temperature stays coherent, allowing a longer and more stable fusion favorable environment.
If you are wondering about how any vessel could hold 150 Million degrees of plasma? Well, the thing is, the temperature is not the same as Heat. The temperature is the measurement of the average kinetic energy of the atoms of the plasma. Heat is the amount of thermal energy transferred through a medium between two systems, a hot to a cooler system. Thus, Heat is dependent on the density of the medium through which it transfer. The plasma is in a vacuum chamber, and the vacuum is a bad heat conductive medium. Thus the Heat that reaches the inner walls of the chamber is fractional compared to the plasma temperature. An example is a Fluorescent tube; the Ionized gas inside the tube is 10 thousand degrees Celsius; however, we can hold a lighted fluorescent tube with our bare hands.
Heat Vs Temperature
As you will note below q (heat variable) is a factor of the mass (m) of the medium by Cp (Temperature Constant) and the change in Temperature (ΔT) .
Naturally, mass (m) is the factor of Density (ρ) and Volume (V) of the Medium measured.
ρ=m/V ⇒ m=ρ x V
⇒ Heat is dependent on Temperature and Density .
Due to the efficiency rate of the current coil magnets used, the state of maturity of the magnetic confinement technology, and the type of the power source supplying the system, the confinement field holding the plasma could become unstable, causing plasma disruptions. When disruptions occur, the plasma destabilizes and get in contact with the vacuum chamber’s inner walls. In anticipation of these events, the scientists introduced regions known as Limiters and sacrificial surfaces into the ST chamber’s inner walls. Those surfaces that behave very much like bumpers contain unique endurance materials that could withstand a high amount of Heat and absorb any damage from the plasma disruptions. Carbon tiles are a type of limiters that cover the inner columns of an ST-MCR. The carbon tiles could handle an incredible amount of heat, so when the plasma touches the carbon, impurities released into the plasma cause it to radiate away, thus saving the chamber’s integrity.
As a matter of fact, the limiters and sacrificial areas are part of the vacuum chamber’s inner wall layer called the Blanket. Several heat-resisting materials make up the modular configuration of the Blanket. As we discussed earlier, carbon tiles tend to cover the surface of the inner column of the ST (Limiters). Mostly, the remaining vacuum chamber walls have a high heat resistant layer like Beryllium that covers the internal walls, then followed by high-strength Copper and stainless steel. There are many variations of the Blanket’s modular configuration. The most promising is called a Breeding Blanket, which also includes Lithium rich ceramic tiles. Breeding Blankets help in the cooling mechanism, absorb neutrons before they destabilize the ST’s structural integrity, and, most importantly, help produce Tritium, a scarce fusion fuel component very integral to the Tokamak’s fusion reaction.
The last and integral part of the ST Vacum Chamber is the Diverters. Located at the Upper and bottom part of the VC, the Diverters are crucial to the fusion reaction’s success in the plasma and the use of the generated heat to produce power. Their role is to suck impurities and neutral particles from the VC to help maintain a stable plasma and absorb the heat generated from the fusion reaction and transfer it to the heat exchange system that runs the power plant turbines and generate electricity.
Merger Compression and the process of Fusion
Let’s dive even further, shall we? Phase one of the Fusion is to raise the plasma’s temperature to the degree that allows fusion reaction to occur, a fusion relevant temperature. The temperature of the plasma injected through the NB injector is yet not sufficient to foster Fusion. Thus, a second external heating method, High-frequency waves, is required to heat the plasma. That is, we microwave the plasma! The high-frequency wave further excites the particles in the plasma, causing their velocity to accelerate in orders of magnitude. Increased particle excitement means increased molecular interaction and pressure, which translates to increased temperature. The plasma’s temperature rises by orders of magnitude. However, this rise is still not enough for a fusion relevant temperature.
The third and final method enables the plasma to reach a Fusion relevant temperature through an internal heating technique called merger compression. In the first stage of merger compression, the Magnetic field system configuration creates two plasma streams above each other. In the second stage, an adjustment in the Toroidal and Poloidal magnetic field applies pressure causing the two plasma currents to merge through magnetic reconnection. As each stream’s magnetic field interacts with the other during the merge, the magnetic energy transforms into thermal energy.
The produced thermal energy is so efficient and high that it allows the plasma’s temperature to rise to 150 million degrees, the sweet spot of relevant fusion reaction. At these temperatures, Fusion occurs between two hydrogen isotopes. The result is Helium, along with high energy neutrons.
Only the Fusion released neutrons, being neutral particles, can escape the electromagnetic field confining the plasma. The emitted neutron bombard the Lithium breeding blankets, which turns Lithium to Tritium and Helium.
The Helium and Tritium are vacuum sucked through the diverters. Tritium is recycled back and mixed with Deuterium and injected back into the NB as fuel for the MCR. The Heat generated from the plasma feeds the built-in cooling system, which transfers the heat into an adjacent electric plant. The transferred heat then operates the plant’s turbines that produce electricity to supply the electric grid.
An operational Fusion reactor is still years away from being realized; however, the technology is catching up with the science. More importantly, many governments and private corporations are increasingly investing in and testing multiple types of fusion reactors.
There is no denying that Fusion power will be instrumental in achieving sustainable space travel, manufacturing, and colonization. It is one of many stepping stones for humanity to reach a Type I Civilization. Below are some further Fusion Reactor technologies that need to be further developed and improved to achieve a sustainable operational Fusion reactor that could be used at scale.
HTC Magnets is one of the Material Technologies that need to be further developed. Its superconductivity properties could be achieved at a relatively high temperature of up to 24 Kelvin; Normal material achieve Superconductivity state at around 1 Kelvin or less. Utilizing HTC Magnetic coils in the Poloidal and Toroidal Magnetic systems will exponentially increase the Magnetic Flux strength (Tesla) applied to the plasma for it through merger compression to achieve Fusion favorable temperature of 150 Million Degrees. The effects of the HTC magnetic coils will also help stabilize the plasma current to avoid plasma disruptions and help achieve ignition.
Achieving Ignition is the ultimate aim of Scientists and engineers for a sustainable fusion operation within the MCR reactors. Ignition is when the plasma stops needing externally induced heating methods to keep it stable. Instead, the byproduct heat from the fusion reaction is sustained within a steady plasma flow without the need for externally induced heating methods. Ultimately, ignition would dramatically increase the Positive gain of the reactor by multiple Folds.
Direct Energy Transfer (DET) through Plasma to direct electricity transfer is another game-changing technology that could replace the Current inefficient System. Currently, Turbines powered by the Heat produced by the reactors would generate electricity. There is a substantial energy loss between the heat Source (MCR) and the Electrical Plant compared to Generating electricity from an endless supply ignition state plasma. With an operational DET, Electricity is generated on the spot, the MCR becomes the turbine, and the Fusion reactor becomes the Power plant.
Last but not least comes Miniaturization, the next holy grail for the road to having MCRs at scale. To sustainably expand and venture into our solar system and colonize our neighboring planets and their moons, our space ships, Orbital stations, asteroid mining factories, and colonies need an efficient and sustainable Fusion energy source. Fusion reactors need to be small enough to fit in our stations, off-world factories, and colonies. To compare, Iter, which is the current most promising ST-MCR being built is around four stories high. That will not do for our purposes. We need to develop reactors that are compact and could be sent out into space for plug and play use.
We are in the age of science and engineering. The future is promising; the technology is developing faster than ever. Among other emerging technologies, Fusion energy will help us realize what Sci-Fi could only imagine possible. I feel lucky to be living in these exciting times.