To view this page ensure that Adobe Flash Player version 11.1.0 or greater is installed.

A new subcritical measurement tool will help scientists protect and preserve the nation’s stockpile. T went y-five years ago l ast month, deep underground in the remote Nevada desert, the United States conducted its last full-scale test of a nuclear weapon. That test, led by Los Alamos National Laboratory, was code-named “Divider” and, though not known at the time, would serendipitously come to represent a divide between two eras of nuclear- weapons science. With the cessation in the 1990s of underground nuclear explosions, nuclear-weapons science was forced in a new direction. Grounded now in computer simulation, modern nuclear-weapons science has produced groundbreaking new discoveries essential to national and global security.