'Ambitious' fusion experiment begins in Oxfordshire

A team comprising more than 100 scientists from 37 institutions is carrying out the experiments at the UK Atomic Energy Authority's (UKAEA) Culham Campus.

The Mega Amp Spherical Tokamak (MAST) Upgrade will be the centre of attention for the next 100 days.

MAST Upgrade (Image: UKAEA) This is MAST Upgrade’s fourth round of experiments, and the largest ever undertaken by the fusion machine.

The scientists aim to conduct more than 50 experiments, generating up to 1,600 plasma pulses.

MAST Upgrade is a compact fusion machine, designed in the shape of a cored apple, in contrast to other ring-shaped tokamaks.

It tests plasma science theories with deuterium fuel - an isotope of hydrogen - using real-world experiments.

One of the experiments (Image: UKAEA) The focus of the scientific campaign will be on maximising the core plasma pressure to determine its effects on the plasma’s properties, and understanding the methods to control the plasma’s exhaust - the intense heat that escapes from the plasma.

Plasma exhaust is one of fusion’s major challenges, and MAST Upgrade is renowned for addressing it.

James Harrison, MAST Upgrade science leader at UKAEA, said: "A diverse team of researchers from across the world will be contributing to this effort.

"This will be the most exciting scientific campaign MAST Upgrade has undertaken to date, with a clear focus on understanding how to confine and stabilise high-performance fusion plasmas while ensuring effective power exhaust."

MAST Upgrade (Image: UKAEA) The experiments will see MAST Upgrade operate at higher temperatures, increasing from 15 million degrees Celsius to 35 million degrees Celsius.

This will create conditions closer to those expected in future machines.

Dr Fulvio Militello, director of plasma science and fusion operations, said: "Previous results have demonstrated the effectiveness of MAST Upgrade’s innovative Super-X divertor, showing a 10-fold reduction exhaust temperature without impacting the hot core plasma.

"This campaign aims to build on these impressive results and will explore whether more compact and cost-effective divertors can achieve similar reductions in exhaust temperature."

MAST Upgrade received significant improvements to its operating system this year, including the addition of a cryoplant.

One of the experiments (Image: UKAEA) This is a facility that produces and distributes the cooling power required for the magnets, thermal shields, and cryopumps to reduce the pressure inside the machine’s inner vessel, and raise the plasma’s temperature.

Dr Militello added: "By utilising our world-leading facilities and expertise at UKAEA, we aim to lead the charge in fusion research.

"MAST Upgrade’s fourth round of experiments will accelerate our scientific progress by deepening the understanding and optimisation of future tokamak designs and fusion powerplants, bringing us one step further to commercial fusion energy."