Internal Toshiba MRI scanner

Helium is critical to the functioning of MRI scanners

UK: Concerns over dwindling sources of helium – a vital element in cryogenic refrigeration – have been allayed following the discovery of a vast gas field in Tanzania.

The discovery could address the increasingly critical shortage of this vital element which is vital in the fields of medicine – particularly in the operation of MRI scanners – welding, industrial leak detection and nuclear energy.Liquid helium is used to cool down the superconductive magnets coil in MRI scanners to a temperature below 10K. It is also used extensively in the Large Hadron Collider.

Despite being the second most abundant material in the universe, helium is scarce on Earth and known reserves of helium have been running short. One of the world’s lightest gases, it is constantly being lost to space. It cannot be artificially produced, and is found in rocks deep below ground.

Now, a research group from Durham and Oxford universities, working with Helium One, a Norway-headquartered helium exploration company, has developed a brand new exploration approach. The first use of this method has resulted in the discovery of a world-class helium gas field in Tanzania.

Their research shows that volcanic activity provides the intense heat necessary to release the gas from ancient, helium-bearing rocks. Within the Tanzanian East African Rift Valley, volcanoes have released helium from ancient deep rocks and have trapped this helium in shallower gas fields.

Independent experts have calculated a probable resource of 54 billion ft³ in just one part of the rift valley. This is said to be enough to fill over 1.2 million medical MRI scanners. To put this discovery into perspective, global consumption of helium is about 8 billion ft³ per year and the United States Federal Helium Reserve, which is the world’s largest supplier, has a current reserve of just 24.2 billion ft³. Total known reserves in the USA are around 153 billion ft³.

“This is a game changer for the future security of society’s helium needs and similar finds in the future may not be far away,” said professor Chris Ballentine of the Department of Earth Sciences at the University of Oxford.

Colleague Dr Pete Barry, who sampled the gases, added: “We can apply this same strategy to other parts of the world with a similar geological history to find new helium resources. This is badly needed given the current demand for helium.”