A 3D-rendered illustration of the anatomy of a cancer cell. Image: © Sebastian Kaulitzki /Stock.adobe.com
These alternative proton accelerators are smaller, more flexible, and ‘hopefully’ cheaper, said a QUB researcher involved in the study.
Researchers from the Queen’s University Belfast (QUB) have simplified the creation of proton beams, a technique which could make obtaining cancer treatment easier.
Proton beams are created by large machines called cyclotrons, which are generally difficult to obtain, explained Dr Charlotte Palmer from the School of Mathematics and Physics at QUB.
They have wide use cases, including testing components for satellites and nuclear reactors, producing radioisotopes necessary for medical imaging, and targeting and destroying cancerous tissues in a technique called proton beam radiotherapy.
“There are only three cyclotrons available to the NHS for cancer therapy in the UK,” Palmer added. “So it’s difficult to access suitable facilities for cancer therapy or for radiobiology research, which is necessary to develop future cancer treatments.”
In a bid to make proton beams more accessible, the team – which also includes researchers from the SLAC National Accelerator Lab and the University of Michigan – have been working on a compact way of creating protons using a laser-plasma accelerator.
Their findings, published in Nature Communications, details an approach for generating stable proton beams with low divergence which can enable “vastly improved” beam capture and transport required for radiobiology experiments.
“This is a smaller, more flexible and hopefully cheap source of protons that can be based at hospitals or universities,” Palmer said.
“When using these alternative accelerators, scientists focus a high-power laser pulse onto a small piece of solid material and vaporise it. This creates bright pulses of protons.”
For a proton source to be useful, several identical pulses are required in quick succession. However, proton pulses vary between different laser shots in accelerators, while pulses are also broad. The broad pulses diverge as they move away from the source – similar to the light from a light bulb, rather than a precise laser beam.
However, in their new study, QUB researchers have demonstrated the creation of focused beams using the accelerator at a pace of five pulses per second.
“The breakthrough shows that it is possible to solve multiple challenges and create more effective protons using compact and cost-effective methods. This paves the way for using protons to further advance research, industry and medicine,” said Dr Matthew Streeter from QUB, who is also the study’s first author.
“Working in collaboration we were able to exploit an innovative thin liquid sheet target. We used this to replace the traditional solid foil target used as the proton source in the accelerator.
“This liquid target renews rapidly, meaning it can support hundreds of pulses per second.”
Moreover, in addition to supporting a large amount of beams in quick succession, the evaporated liquid creates a vapour which allows for the proton beams to focus, explained Streeter.
“When the liquid evaporated, it formed a vapour cloud around the target. The interaction of the proton beam with this cloud caused the proton beam to focus. This was amazing as it made it brighter and more collimated – a much more precise beam.”
In December, QUB and the University College Dublin joined efforts to launch a three-year, all-island cancer alliances partnership to further research and collaboration in the field.
Don’t miss out on the knowledge you need to succeed. Sign up for the Daily Brief, Silicon Republic’s digest of need-to-know sci-tech news.
