British nuclear fusion reactor JET creates a new record for global energy output

European scientists at the Joint European Torus (JET) nuclear fusion reactor facility have achieved a significant scientific milestone by releasing 69 megajoules of regulated and sustained fusion energy, a new world record. Their experimental drive to confirm operation scenarios for future fusion machines under settings as near to ITER and future fusion power plants as possible led to this breakthrough.

In September 2023, the JET facility of the U.K. Atomic Energy Authority (UKAEA) in Culham, U.K., hosted an ambitious experimental campaign by the EUROfusion consortium, a group of fusion laboratories from across Europe. Their objective is to evaluate operating scenarios derived from small and medium-sized European devices in order to prepare the ground for the future fusion power plants and the international ITER project.

Nuclear fusion reactor JET is distinct from current tokamak devices, which enclose a hot, ionized fuel or plasma cloud in a magnetic field cage, since it is capable of operating with deuterium-tritium fuel, which is the building block for fusion devices such as ITER and the demonstration power plant DEMO.

Thanks to innovative scenarios employed to organize and control their plasma, researchers at the JET facility of the U.K. Atomic Energy Authority (UKAEA) have established a new record for fusion energy, releasing 69.26 megajoules of heat in a single pulse. By releasing the energy from just 0.21 milligrams of fuel over the course of six seconds, a major breakthrough was accomplished. The energy recorded is the same as what is produced when two kilograms of coal are burned.

With this new accomplishment, the EUROfusion team surpasses their previous world records of 22.7 megajoules (1997) and 59 megajoules (2022), both of which were also set at JET. The JET scientists’ comprehension and mastery of the intricate fusion processes were demonstrated when they were able to consistently replicate the fusion conditions required for the new record in several experimental pulses.

Two hydrogen isotopes, deuterium and tritium, were heated to a temperature of 150 million degrees Celsius in order to accomplish the record-breaking achievement.

The best prospects for fusion energy are deuterium and tritium because of their high fusion cross-section and low ignition temperature. Seawater contains deuterium, but common metal lithium can be used to make tritium.

Without contributing to global warming, the fusion of deuterium and tritium produces helium, which releases a vast amount of heat energy. Since fusion cannot initiate a runaway process and generates no persistent waste, it is intrinsically safe.

“We can reliably create fusion plasmas using the same fuel mixture to be used by commercial fusion energy powerplants, showcasing the advanced expertise developed over time.”

Dr Fernanda Rimini, JET Senior Exploitation Manager, JET Scientific Operations Leader

“Our successful demonstration of operational scenarios for future fusion machines like ITER and DEMO, validated by the new energy record, instill greater confidence in the development of fusion energy,” said Professor Ambrogio Fasoli, Programme Manager (CEO) at EUROfusion. “Beyond setting a new record, we achieved things we’ve never done before and deepened our understanding of fusion physics.”

JET represents a significant breakthrough in the field of fusion energy research. It is a key research site of the European Fusion Programme and the biggest and most successful fusion experiment in history. In order to fulfill the world’s future energy demands, JET has sought safe, low-carbon, and sustainable fusion energy solutions since its founding as a cooperative European initiative in 1983. It has given scientists vital insights into the intricate mechanics of fusion, enabling them to organize the international fusion experiment ITER and DEMO, the demonstration fusion power plant that the European fusion community is now designing.

Constructed in Europe and utilized cooperatively by European scholars throughout its existence, JET was acquired by UKAEA in October of 2021. The device, which produced 105,842 pulses at its 40th anniversary celebration in June of this year, will discontinue plasma operations by the end of 2023.