Inertial fusion energy: the solution to damaging greenhouse gas emissions?

25 February 2020

Peter Norreys, Professor of Inertial Fusion Science in Oxford University’s Department of Physics, is bringing together the world’s leading scientists and policy advocates to begin preparations for the next generation facilities that could unleash the potential of inertial fusion energy – and help to halt climate change.

‘The impact of realising inertial fusion energy will be transformative for humankind,’ explains Peter. ‘There are no long-lived radioactive by-products, provided that careful selection of the reactor chamber materials is made. An inertial fusion energy reactor is compatible with the existing electricity infrastructure distribution and generation grid. The process is inherently safe, each nation can have security of supply, and the fusion fuels are abundant and will satisfy humankind’s needs for millennia to come.

‘Now is the time to be talking about this: while it is true that ignition has not been achieved so far, it is now arguable that sufficient progress has been made in understanding laser-driven burning plasmas to begin to contemplate what the next facilities might look like. Controlling emissions is essential in combating climate change and so the search for alternative energy sources is a global priority; I am confident that present and next-generation scientists in our universities, national laboratories and industry are up to the challenge and are capable of real delivery.

‘It is significant that this event is taking place now, as it marks 80 years on from the Frisch-Peierls memorandum, arguably one of the most historic documents of the 20th century. And here we are today, bringing people together from around the world to discuss how the understanding of high energy density science could potentially be a huge force for good.’

In January 2019, Professor Norreys was awarded an Enabling Research grant from EUROFusion, part of EURATOM. The consortium comprises fifteen laboratories in nine nations, including the UK. Overall, the project has enabled increased co-operation and co-ordination of inertial fusion energy activities using high power laser facilities across Europe. This year’s scientific meeting builds on the success of last year’s Institute of Physics International Conference on High Energy Density Science.

The meeting is intended for researchers in relevant fields and is free to attend; registration is essential.
Register now.

Recorded audio will be available after the event and papers will be published in Philosophical Transactions of the Royal Society A.

How does inertial fusion energy work?
Inertial fusion energy involves the compression of matter to ultra-high densities (300–1,000 gcm-3) and temperatures (greater than 50,000,000 C) over a very short period of time. This is done by irradiating and imploding a small spherical shell containing isotopes of hydrogen (deuterium and tritium), either directly using intense laser beams or by first converting the laser energy to soft X-rays. Once these density and temperature conditions are met, then the hydrogen-like ions have sufficient kinetic energy to overcome the repulsive barrier associated with their positive electric charges and for strong nuclear force to fuse these isotopes into helium ions.

As the rest mass of the fusion products (a helium nucleus and a neutron) is less than the combined masses of the deuterium and tritium ions (given that energy equals mass multiplied by the square of the speed of light, i.e. E = mc2), this results in a massive release of energy for each fusion event. If a sufficient number of these fusion reactions occur, then more energy can be generated than was used to drive the compression in the first place. It should be possible to capture that energy so that it can be turned into heat in order to drive a steam turbine for electricity generation.

Image credit: © CEA