A year after complaining that the tap on their helium-3 supply had been shut off, US users of the gas for scientific applications say the flow has resumed. But researchers abroad continue to face prohibitively high prices for it, when they are able to find it. Although the shortage of 3He has spurred rapid advances in the development of alternatives for neutron detection, little progress has been made on adding new supplies.
The US inventory of 3He has stabilized since shipments from the US stockpile for use in radiation portal monitors were halted early in 2009 and an interagency task force took over control of distributions (see PHYSICS TODAY, June 2010, page 22). By then, the Domestic Nuclear Detection Office (DNDO) had drawn an estimated 60 000 liters from the US reserve to equip the approximately 1300 3He-guzzling monitors that have been installed at US ports...
