Over the last 8 years the cost of helium has ballooned. In 2008 it cost around £2.4 per litre. In 2015 the cost was £7.81 per litre - an increase of well over 300%. Ironically, Helium is the second most abundant element in the universe, after hydrogen. But down here on Earth, the lighter than air gas, left to its own devices, cannot be retained by the Earth’s gravitational field and literally just floats away.
ISIS is a major user of Helium. Liquid helium is used in cryogenics, to keep samples cool, on a wide range of instruments. Two thirds of experiments carried out at ISIS require cryogenic sample environments. Inside the target stations helium gas is used in gas form as it is inert, allowing neutrons to pass through unscathed. The yearly usage is of the order of 45,000 litres - an annual bill of over£500k at current market prices.
The helium recovery project began in 2013, with the aim of reducing the helium bill by capturing, compressing and storing helium, before making available for re-use. Led by Richard Down and Oleg Kirichek from the ISIS sample environment group, the project set out to identify best practice in helium recovery and use this knowledge to design and build a system for ISIS.
The recovery system will capture “waste” helium from the cryogenic sample environments that currently escapes into the atmosphere and is lost. The captured helium will then be processed in R108 before being returned to the target stations in gas form. This form of recycling presents a potential saving of £55k annually. The next stage is to reliquify the helium so that it can be used in multiple experiments, with the potential to save nearly £500k / year.
Richard Down says, “The huge increase in the cost of helium over the past 8 years means organisations around the world are looking for ways to save and reuse helium. The ISIS helium recovery system was developed by sharing expertise with facilities like the ILL and HZB. Once the ISIS system is up and running we will be in a position to share our own knowledge, internationally but also at home. Certainly CLF and Technology here at RAL have been closely following our progress.”
Zoe Bowden, ISIS deputy director, says, “I’m delighted to open R108 and to celebrate the significant milestone of the system being ready to compress gas. This is a shining example of using technological innovation and knowledge sharing to bring down costs in very real terms. Congratulations to Richard and the team!”
