National collaboration uses laser research to advance fusion power plant designs
A collaboration between the University of Leeds, UKAEA, and Oxford Cryosystems has demonstrated that an innovative laser technology has the potential to be used in future fusion power plants.
The University of Leeds and the United Kingdom Atomic Energy Authority (UKAEA) completed the first stage of experiments to test whether compact Quantum Cascade Lasers (QCLs) could be suitable to continuously monitor extremely hot plasmas, up to 200 million °C, in a fusion machine.
To assess the suitability of QCLs, the team conducted extensive tests on laser beam shape, stability, and long-duration operation. Lasers with wavelengths in the range of 20-150 microns (2-15 THz in frequency) are currently not commercially available, giving rise to the “THz gap”. QCLs offer promise to fill this gap based on these initial tests demonstrating their potential. The team are now planning their next phase of research, which could see the lasers tested on fusion machines.
The use of QCLs could see a move from a four-metre-long laser, requiring expensive gases and high voltage, to a device the size of a memory stick with very low power consumption, 10 % of the cost, and yet with 10 times more laser power. These benefits could mark an encouraging step towards the future commercialisation of fusion energy.
QCLs emit in the mid- to far-infrared spectrum and will be used to measure plasma density continuously. This is essential as the density of plasma directly influences its behaviour and, therefore, requires monitoring and control. Lasers are one of the key ways to monitor plasma, and commercial fusion power plants will require highly reliable sensor systems for non-stop operations.
Quantum Cascade Terahertz Laser chip (QCL THz) mounted inside the customised Oxford Cryosystems Phenix vacuum chamber at the UK Atomic Energy Authority (UKAEA) Culham Campus in the United Kingdom. Photo courtesy of UKAEA.
QCLs are operated in a very cold environment, inside a cryogenic device called a cryostat. Oxford Cryosystems and QMC Instruments supported this research with Oxford Cryosystems providing essential support with their ‘Phenix’ cryostat.
Lasers are currently used in various industries, such as medical diagnostics, industrial gases monitoring, and imaging systems. This research has demonstrated that they may also be a key technology for fusion energy.
Dr Alexandru Boboc, Division Task Manager for Diagnostics Innovation at UKAEA, said: “This research showcases the world-leading science and engineering taking place in the UK. We are pleased with the initial results and hope this research could support the acceleration of innovation for the design of future fusion power plants.”
Dr Joshua Freeman, an Associate Professor in Electronic and electrical Engineering at the University of Leeds, worked on the breakthrough alongside Professor Edmund Linfield, Professor Giles Davies, Dr Mohammed Salih, and Dr Lianhe Li.
He said: “We are working with UKAEA to replace existing gas laser technology in fusion diagnostics with more compact and powerful lasers, which could solve a number of problems such as cost and sustainability.”
“Leeds is a world leader in the development of QCLs. We have been developing compact semiconductor lasers that emit terahertz light, and we currently hold the world record for the highest power output from this type of laser.”
Dan Bodio, Managing Director at Oxford Cryosystems, added: “We’re incredibly proud to support UKAEA with this project. Customising the Phenix hardware and control software to meet their specific needs was a rewarding challenge for our team, and we’re eager to see how QCLs influence the future of fusion technology.”
Further information
- Learn more about the UK Atomic Energy Authority (UKAEA) Culham Campus.
- Learn about the TeraCom Programme Grant, through which Leeds’ researchers aim to develop the first integrated high-throughput wireless communication systems operating at carrier frequencies >2 THz.
- For media enquiries, email Faculty Communications Manager Matt Gardner via M.D.Gardner@leeds.ac.uk.
