Hydrogen-boron Fusion gets an Energy Boost
Injecting boron into a magnetically contained hydrogen plasma may be a productive way to finally reach the promise of nuclear fusion.
Not long after the December 2022 announcement that the world’s first scientific energy breakeven in a controlled fusion experiment has been reached by a team at Lawrence Livermore National Laboratory (LLNL), TAE Technologies working in collaboration with Japan’s National Institute for Fusion Science (NIFS), has announced it has achieved the first-ever hydrogen-boron fusion in a magnetically confined fusion plasma.
Energy breakeven means the fusion reaction produced more energy than the energy used to drive it, and although the TAE breakthrough didn’t achieve this milestone, it still is an interesting and potentially viable variation of previous fusion experiments.
Next generation TAE fusion reactor. Image used courtesy of TAE Technologies
A History of Developing Fusion Power
TAE Technologies is based in California and was founded in 1998 to develop and commercialize fusion power. The company has built five generations of laboratory-scale fusion devices, has over 500 employees, and received 1,100 patents.
The hydrogen-boron breakthrough, published in Nature Communications, is significant as it represents the first time hydrogen-boron fusion has been achieved within a magnetically confined hydrogen plasma. Also called proton-boron (or p11B) fusion, it differs from traditional deuterium and tritium (DT) fusion in several significant ways. When deuterium and tritium undergo a fusion reaction, they produce a helium nucleus containing two protons and two neutrons while releasing a great deal of energy and an energetic neutron. The energy can be used to convert water into steam to power a turbine and generator to create electricity.
Proton-boron (or p11B) fusion. Image used courtesy of Adobe Stock
Non-toxic Energy Source
This kind of hydrogen-boron fusion is also called aneutronic fusion because the majority of energy released is carried by charged particles rather than high-energy neutrons. Because hydrogen and boron are abundant in nature, non-toxic, and non-radioactive, they are attractive for future energy sources. The p11B fusion reaction produces almost no neutrons and only results in helium nuclei in the form of alpha particles. There are no radioactive byproducts to dispose of.
Instead of using the fusion heat energy to produce steam, the charged particles formed in the hydrogen-boron fusion reaction can be collected and used to make electricity. The plasma temperature required is 30 times higher than that required for a DT fusion reaction(more than 30 million °C or 54 million °F), requiring greater amounts of input energy which makes finding an energy breakeven point even more difficult.
Fusion Energy Powering the Grid
It is one thing to produce fusion under controlled laboratory conditions but quite another to produce energy that can be delivered reliably to a power grid. The TAE announcement is far from that, as it documents the first measurement of hydrogen-boron fusion within a magnetically confined plasma. Previously p11B fusion had only been measured in laser-produced plasmas, so the significance of the work is proof that these fusion reactions can occur in the types of reactors that the company plans to build in the future.
In many ways, the announcement was a byproduct of other research the company and NIFS undertook. Boron was in use, injected into a hydrogen plasma to condition and clean the walls of the containment vessel. By placing an alpha particle detector in the fusion chamber, the team could observe 150 times the number of alpha particle pulses when boron was injected into the hydrogen plasma, confirming the existence of the p11B fusion reaction.
Although it seems a stretch to go from a blip from an alpha particle detector to a full-scale working power grid running on fusion energy, TAE has plans to have the world’s first hydrogen-boron fusion reactor up and running and feeding electricity to the power grid by the early 2030s. After decades of unfulfilled predictions of limitless power, fusion suddenly looks much more promising.