By Jeremy Beck
China is now leading the world into an industrial and scientific revolution, the sheer scale of which will of necessity soon require an entirely new form of energy, never before mastered on Earth: controlled thermonuclear fusion power, using helium-3 (He-3) as its fuel. The He-3 isotope is extremely rare on Earth, but exists in abundance on the Moon, and the Chinese leadership has already begun an ambitious program to acquire it. About three-fourths of China’s energy is now produced by coal-fired power plants, but a typical coal train of more than a kilometre long, carrying 5,000 tonnes of coal, would be replaced by just 40 grams of He-3, dramatically reducing transportation costs. Just eight tonnes of He-3 in fusion reactors would provide the equivalent energy of one billion tonnes of coal, burned in power stations. China’s plan to bring back He-3 from the Moon will benefit not only the Chinese, but all mankind, just as any scientific breakthrough anywhere in the world has always done. Moreover, China is not alone in needing huge new supplies of energy. Human civilisation now and in the foreseeable future already requires orders of magnitude more energy, while per capita energy consumption must also rise dramatically, if we are to eliminate poverty and transform industry, agriculture, transport and water management everywhere.
The Moon—“Persian Gulf” of the Solar System
Professor Ouyang Ziyuan, the chief scientist of the Chinese Lunar Exploration Program (CLEP), has said that the Moon is so rich in He-3, that this could “solve humanity’s energy demand for around 10,000 years at least.” While talking about the Moon’s reserves of iron and other metals, Ziyuan particularly drew attention to He-3, which he called “an ideal fuel for nuclear fusion power, the next generation of nuclear power.” He added, “It is estimated that reserves of helium-3 across Earth amount to just 15 tonnes, while 100 tonnes of helium-3 will be needed each year if nuclear fusion technology is applied to meet global energy demands. The Moon, on the other hand, has reserves estimated at between one and five million tonnes.” There are two stable isotopes of helium on earth, He-3 and He-4. The nucleus of each has two protons, but He-3 is lighter because it has only one neutron, while He-4 has two. He-3 accounts for just 0.000137 per cent of Earth’s helium, while the rest is He-4. He-3 is emitted from the Sun and carried throughout the Solar System by the solar winds, but is repelled by the Earth’s magnetic field, with only a tiny amount penetrating the atmosphere in cosmic dust. On the Moon, however, which has a weak magnetic field and no atmosphere, He-3 over the eons has been deposited in signifi cant quantities. In recent years China has launched a remarkable plan not only to land on the Moon in the near future, but to industrialise it. At the centre of this program lies the intent to mine He-3 and bring it back to Earth. The long-term perspective, emphasised by Ouyang Ziyuan, is shared by the famous Apollo 17 astronaut and former U.S. Senator Harrison Schmitt. Following the December 2013 landing of China’s Yutu (Jade Rabbit) lunar rover, Schmitt observed, “China has made no secret of their interest in lunar helium-3 fusion resources…. In fact, I would assume that this mission is both a geopolitical statement and a test of some hardware and software related to mining and processing of the lunar regolith.” Schmitt has numerous papers and books on the prospect of lunar development and helium-3 mining, and has worked closely with the group at the University of Wisconsin which is developing helium-3 fusion technologies. Yutu landed as part of the Chinese robotic lunar exploration program named Chang’e, after the mythical goddess of the Moon. Chang’e-1, the first probe, was launched on 24 October 2007. It provided high resolution images of the lunar surface and data for estimating He-3 reserves. The millions of tonnes of He-3, estimated by CLEP, mean that the Moon will be the “Persian Gulf” of the solar system.
A Second-Generation Fusion Fuel
Most fusion experiments, to date, have used first-generation reactors, fuelled with the isotopes of hydrogen—deuterium and tritium. Deuterium may be fused with tritium (DT) or fused with itself (D-D). This type of reaction, however, presents a big problem because most of the energy from the fusion reaction is in the form of neutrons, rather than charged particles. A D-T fusion reaction releases 80 per cent of its energy in a stream of highenergy neutrons. As particles with no charge, neutrons cannot be contained by the magnetic field used to contain the fusion reaction, and they are highly destructive to anything they hit, including the reactor containment vessel. A second-generation approach to controlled fusion power involves combining He-3 and deuterium. This reaction produces He-4 nuclei and high-energy protons. Some D-D side reactions occur, producing neutrons, but upwards of 90 per cent of the energy produced is in the form of charged particles, which can be directed away from the reactor walls by magnetic fields and used for generating electricity.
Direct Energy Conversion
Plasma products from fusion can be separated by charge, using magnetohydrodynamic or electrostatic “direct conversion”, and produce electricity directly. Conventional power stations use heat to boil water, and steam turbines to run a generator. Only 30-40 per cent of the energy released by the fuel (coal, natural gas, uranium etc.) gets converted into electricity, while the rest of the heat energy is lost as “waste heat”, typically in cooling towers or ponds. Eliminating the steam turbine and producing electricity directly will more than double the amount of electric power generated for every unit of fuel used. Magnetohydrodynamics (MHD) is a technology that can be used with virtually any fuel, such as, once again, coal, oil, natural gas, etc., to generate electricity directly from a hightemperature plasma. The basic principle in MHD conversion is to pass a high-temperature plasma through a magnetic field. The magnetic field creates an electrical current in the plasma, which is drawn off by electrodes along the length of the channel through which the plasma flows. There are essentially no moving parts, since the plasma is itself moving through the magnetic field. These are not simply theoretical concepts: in the 1970s, researchers at Argonne National Laboratory achieved a 60 per cent effi ciency with a nuclear fission-powered MHD system, and the experimenters were confident they could reach a level of 80 per cent with future developments. Despite these exciting studies and results, serious MHD direct conversion research was basically shut down in the 1980s. MHD must be revived for generating electricity with fusion. The other “direct conversion” method uses an electrostatic converter, essentially a linear particle accelerator run backwards. Fast ions from the fusion plasma enter the “exit” of the accelerator and are decelerated, before being finally collected. By this process, the kinetic energy of the ions is directly converted to electric potential energy.
The Isotope Economy
China’s fusion program is not solely about acquiring power for the economy in its existing state. The scientific research will open up many other technological breakthroughs, creating a new isotope economy. Atoms of the same element, but varying in mass, are known as different isotopes of the element. For example, tin has ten stable isotopes—the most for any element; tin-112 is the lightest and tin-124 the heaviest. Heavier isotopes contain more neutrons in the atomic nucleus. An isotope economy will incorporate the 3,000-some isotopes of the Periodic Table into our economy. We can separate and exquisitely fine-tune subatomic processes, generating various species of atoms as raw materials for industrial production. China’s nuclear fusion science is progressing at the Center for Fusion Science (CFS) and the Institute of Plasma Physics Chinese Academy of Sciences (IPP). The CFS consists of eight research divisions, with 285 personnel, including senior academic staff and research scientists. The IPP has more than 400 staff, of which 223 are scientists or engineers. A few of the countless potential fusion applications and technologies that will transform our economy are highlighted here.
Seawater Desalination
There need be no worldwide water shortage. The oceans cover 71 per cent of Earth’s surface, with an average depth of more than four kilometres. Dry continental areas may use water desalination to address local water shortages, and nuclear power is the most efficient way to produce cheap fresh water. China has begun nuclear-powered desalination with the new Hongyanhe Nuclear Power Plant. The site incorporates a seawater desalination plant producing 10,080 cubic metres of potable water per day. While fission power can produce relatively cheap desalinated water, fusion power’s massive increase in energy fl ux density will enable its large-scale use, even to replenish entire dry river beds. There need not be any deserts on Earth.
The Fusion Torch
The “fusion torch” design, first proposed in 1969 by Bernard Eastlund and William Gough of the U.S. Atomic Energy Commission, uses ultrahigh temperature fusion plasma, diverted from a fusion reactor core, to reduce virtually any feedstock (low-grade ore, fission by-products, seawater, garbage from landfills, etc.) to its constituent elements. Once the feedstock has been injected into the plasma, the elements become dissociated into electrons and ions, and the desired elements (or isotopes) can be separated from one another by atomic number or atomic mass, creating pure, newly synthesised mineral “deposits” from virtually any substance. For instance, an average cubic mile of dirt contains approximately 200 times the amount of annual U.S. aluminium production, eight times the iron production, 100 times the tin, and six times the zinc, but most of it is not in a concentrated form, making it impossible to effectively mine and process with current technologies. Lower-grade ores and lower concentrations of ores, which are currently useless to us, will suddenly become available resources. Dirt will become ore. Scrap materials, which already contain concentrated elements, can also be efficiently reprocessed as new raw materials. Urban landfills, containing disorganised forms of all the elements we already use, will become one of the most valuable sources of materials to be processed. Beyond accessing existing resources, the ability to select and harvest specific ratios of isotopes and elements in substantial quantities creates the potential for a revolution in the qualities and properties of materials. For example, specialty steel can be custom built down to the isotopic level, improving capabilities to handle high-energy processes ranging from industry, to fusion reactors, to space travel. With the fusion torch, bogus claims about “limited resources” will fly out the window.
Schematic of fusion torch processing of solid waste. credits- Bernard Eastlund, William Gough, US Atomic energy commission
Chemical Processing by Fusion Torch
Another use for the fusion torch will be to transform energy from the plasma into radiation across the entire electromagnetic spectrum, for use in processing industrial materials and chemicals. By injecting selected “seed” materials into the fusion torch, the frequency and intensity of the emitted radiation from the reaction can be manipulated. Within the fusion plasma it is possible to maximise this energy in specific, narrow bands of the electromagnetic spectrum. This radiation can then be transmitted through a “window” material, to a fluid or other body. Because the frequency of this radiation can be tuned to the material being processed, existing limitations on bulk processing of materials, caused by the limits of surface heat transfer, can be largely overcome. For example, ultraviolet radiation could be generated to sterilise industrial process water or drinking water. Neutrons from the fusion reaction could be used for heating process materials to temperatures ranging from 1,000 °C to more than 3,000 °C. The neutrons could be used themselves, or converted via a blanket material into high-energy gamma rays for catalysing chemical reactions—thus directly converting the fusion energy into chemical energy. This could greatly increase the efficiency of the production of industrial chemicals requiring high heats or high activation energies, such as hydrogen, ozone, carbon monoxide, and formic acid. This increased power over materials and chemicals processing opens up a scale of production never before possible.
Fusion Rockets
The next platform in the evolution of our human economy, the control of atomic processes like those found in our Sun, will be applicable not only to energy production and materials creation here on Earth: the development of this power will be the means to conquer the entire domain of our Sun’s influence, the Solar System, and will ultimately put us in range of our closest neighbouring stars. To achieve this will require full exploitation of the dynamic relationships that currently exist between the fields of plasma, laser, antimatter, and fusion research, i.e., high-energy-density physics, where much of the work is already vectoring towards the next generation of space propulsion techniques. Only fusion propulsion can generate acceleration conditions equivalent to one earth gravity (1g), which are necessary to sustain the human body. Acceleration at 1g, the equivalent of Earth-like gravity, would mitigate some of the deleterious effects of microgravity, and reduce travel time, thus limiting exposure to harmful cosmic radiation. For example, at 1g acceleration, achieving a maximum velocity of 3,000,000 km/h, a trip to Mars would take just two days when the planet is at its closest to Earth.
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