TRIUMF researcher Paul Schaffer works at a “hot cell,” where radioisotopes are manipulated and extracted using remote operator arms. Photo by: Tim Leshuk
Vancouver-based TRIUMF, already an international focal point for accelerator-based science, is poised to help researchers take stock of radioactive isotopes that have been too rare to examine in any kind of practical way. This capability comes with the recent launch of a new facility, the Advanced Rare Isotope Laboratory (ARIEL).
Using home-grown superconducting acceleration technology, ARIEL increases the number of beam-lines that TRIUMF can utilize to irradiate targets for isotope production. Beyond simply increasing the quantity of isotopes from molybdenum, technetium or fluorine, which have well-established medical and industrial uses, ARIEL provides the scope to produce more unusual radioactive species from elements such as actinium, bismuth, radium, lutetium, strontium and yttrium.
According to Paul Schaffer, a principal investigator with TRIUMF, we know little about these species largely because there has been too little to work with. Schaffer offers the example of metal actinium, whose isotope 225Ac has demonstrated the potential to kill cancerous tumours, although it would need to be employed in combination with biochemical agents that could prevent it from accumulating in other parts of the body. Unfortunately, such clinical use has not been pursued because only a handful of places in the United States and Germany produce this particular isotope. The meagre volume of available 225Ac means it would cost a laboratory about US$1,500 per millicurie to obtain, an amount far beyond what most research budgets could afford.
Schaffer points out that all of these places combined would make just a single curie of 225Ac annually. However, he noticed that TRIUMF has been indirectly making as much as three curies at a time, as part of a regular irradiation process where this particular isotope is simply being warehoused for later disposal. “I want to tap into this warehouse and make it useful for the Canadian community,” he says. “I want to bring prices down. I want to encourage research. I want to encourage clinical use.”
With ARIEL, Schaffer says, TRIUMF could dramatically improve access to 225Ac so that its properties could be studied more thoroughly. And this is just one example among thousands of isotopes that could ultimately be explored for applications ranging from oceanography and botany to pulp and paper production. He also notes that the accelerator launch is just the halfway point in a 10-year initiative to ramp up TRIUMF’s isotope output. A second phase of the ARIEL installation will take place over the next five years, securing what Schaffer and others regard as a world-leading reputation for cutting-edge work across the full array of isotope science. “TRIUMF is a unique melting pot of science that enables this type of work to be done seamlessly across a number of different disciplines.”