EFS is experimenting with a new fusion energy technology that does not emit hazardous radiation and can be scaled up or down to almost any size.
Electric Fusion Systems (EFS) has announced that it has carried out successful aneutronic fusion experiments in the laboratory. EFS, founded in 2020, is experimenting with a new energy technology that does not emit hazardous radiation.
Aneutronic fusion is what it sounds like: very little of the released energy is in the form of hazardous neutrons. The process devised by EFS involves lithium + proton, with helium + energy output products converted directly into usable electricity.
The inventors and co-founders, Ken E. Kopp and Ryan S. Wood, told EE Times that they have found a safe way to generate fusion chain reactions. Their Light Element Electric Fusion (LEEF) reactor was built in miniature to suit a wide range of applications and it was created by following a series of measurements which confirmed the fusion reactions through neutron detection, gamma spectroscopy and optics. As observed in optical spectra, dense plasma initiates proton-lithium fusion reactions (Figures 1 and 2).
The speakers said their technology is in the patent phase and will provide constant energy without generating pollutants, thus helping to sustainably reduce greenhouse gases and delay climate change. They also said: “We have set ourselves the goal of not only demonstrating and validating the technology with the scientific community but licensing the intellectual property to strategic industries to accelerate global adoption”.
LEEF has no minimum critical mass: it can be produced in small or large sizes in a factory. It has no special nuclear materials of concern and no high-level radioactive waste. This combination reduces the design, licensing, construction and safety costs for possible adoption.
In recent years, experiments in the field of nuclear fusion have mainly used the two simplest reactants, deuterium (composed of one proton and one neutron) and tritium (one proton and two neutrons) — both of them are isotopes of hydrogen. This same fusion reaction, which produces a helium nucleus (two protons and two neutrons) and a neutron, occurs in “young” stars at the beginning of their life cycle. Under experimental conditions, the choice of these elements is dictated by the advantage of the reaction rate, i.e. the probability with which the two elements give rise to the process. However, this reaction produces an intense stream of very energetic neutrons, which pose a significant radiological risk and must therefore be shielded with thick concrete shielding surrounding the reactor.
Recent advances in laser technology and a deeper understanding of laser-plasma interactions and laser-accelerated particle beams have opened up new paths for the realization of fusion fuels based on “aneutronic” nuclear reactions that produce less high-energy radiation.
For EFS, the lithium-proton fusion reaction is the best option as it generates virtually no neutrons or radiation and has a high-energy output.
A proton is a hydrogen atom stripped of its electron; lithium (Li) is a light, non-radioactive element that is used in lithium-ion batteries and many other industrial applications. As the speakers pointed out, the hydrogen-lithium combination is a clean and abundant fusion fuel cycle, making it the ideal fuel source for EFS’s commercial fusion solution.
EFS fusion reactor
EFS believes it has achieved a new solution on fusion physics by employing a cyclic induction process to harness the energy of fusion chain reactions as an electric arc, which passes through a plasma fuel resulting in direct conversion to electricity. The plasma density is an essential factor and determines the efficiency of the system. EFC defines such a system as a “fusion-plasma transformer” where one of the keys is fuel, which must be super dense.
EFS states this will allow cutting the cost of electricity by a factor of ten. “In the US, costs are around $100 per megawatt-hour (or 10 cents per kWh), and the advent of new clean technologies could reduce such costs,” said the speakers.
“Our prototype technology is an aneutronic fusion reactor capable of delivering tens of kilowatts of power, but scalable to megawatts. The plasma transformer is ~90% efficient at converting diamagnetic pressure to electricity.”
The EFS fuel operates in a supercritical fluid state. Ion temperatures are of the order of MeV resulting in significant chain reactions during each fusion cycle. The process is cyclic (100-1000’s of hertz) and the fusion energy is extracted at each cycle through magnetic induction (figures 4 and 5).
When fusion reactions occur in a chain reaction state, they create explosions of charged particles that are electromagnetically coupled to the reactor’s oscillating magnetic field, which is subsequently transformed into electricity. Basically, it’s a gain transformer that uses fusion plasma as its core. “This allows us to use efficient power electronics to collect the EMF and then regulate it as a switching power supply. So, the direct output conversion can be, for example, 800 VDC or 35 kilovolts AC,” said the speakers.
They added, “we have an arc that goes through these electrodes and that expands with the fusion reactions, and then creates a magnetic pressure and an electromagnetic force that we capture in a plasma core transformer. And these can be developed on a large scale in industry, replacing normal transformers. Then, once you’ve put the energy into the coil, you can use typical power conversion electronics to bring the power up to whatever AC or DC voltages and frequencies yet,at the same time you need some control electronics to modulate the reactions. Essentially, what we’re doing is using the nature of fusion plasma to couple directly to the magnetic field and transfer the energy (an electromagnetic force) into the surrounding inductor coils. Hence we have a gain core transformer dirven by burning lithium and that’s really the source of the energy that we’re generating.” It is straightforward hot fusion– E=Mc2.
Magnetic and electric fields, plasma physics, pressure confinement, electromagnetic pulses and energy extraction through inductive coupling, together with electrical engineering solutions, could combine to finally offer new opportunities for fusion physics.
This article was originally published on EE Times.
Maurizio Di Paolo Emilio holds a Ph.D. in Physics and is a telecommunication engineer and journalist. He has worked on various international projects in the field of gravitational wave research. He collaborates with research institutions to design data acquisition and control systems for space applications. He is the author of several books published by Springer, as well as numerous scientific and technical publications on electronics design.