Tabletop laser enriches isotopes

Materials made from isotopically pure elements have medical, industrial, and other uses. The production of bulk quantities of isotopes has traditionally been left to government facilities, where large pieces of sometimes-antiquated equipment perform the task slowly and expensively. Now, researchers at the University of Michigan (Ann Arbor, MI) have enriched isotopes of gallium, boron, and other elements using an ultrafast tabletop Ti:sapphire laser. Although the amount of isotopic matter produced thus far is small, so is the size of the equipment needed to produce it.

The discovery of the technique was accidental, according to Peter Pronko, research scientist. Aided by an instrument called a sector-field electrostatic analyzer, the group was studying the ion plumes given off when a femtosecond laser ablates material in a vacuum. The analyzer produces a time-of-flight spectrum containing components separated by ionic charge and isotopic mass. "The isotope ratios were way off," says Pronko.