Femtosecond Lasers Simplify Plasma Research

Studying the behavior of electrons and atoms in super-dense plasmas can be done with a table-top laser, say researchers at the University of Michigan, Ann Arbor. For example, professor Don Umstadter and colleagues used a high-resolution femtosecond laser -- which can deliver a trillion Watts of power in 1015 seconds -- to watch how and when electrons and atoms organize themselves in environments such as those in fusion reactors or stars. Umstadter says the approach permits the first "clean measurements in a system that's usually never clean." In the astrophysical realm, the data can help calibrate measurements of the conditions in the interior of planets or collapsed stars. And it also should help in designing laboratory fusion reactors, where measurements of the structure of this unusual state of matter are made difficult by the smearing-out of information by rapidly changing conditions.