Computers Simulate Nuclear Blast

Thursday, July 20th 2000, 12:00 am
By: News On 6

LOS ALAMOS, N.M. (AP) — Computers for the first time have simulated the beginning of a hydrogen bomb blast in full-scale 3-D, Los Alamos National Laboratory scientists say.

The simulations took 42 days to run using super-fast computers at Los Alamos, Lawrence Livermore and Sandia national laboratories.

The simulations, completed April 30 and announced this week, are a major step toward replacing underground nuclear test blasts.

A Lawrence Livermore simulation showed the detonation of the plutonium spark plug that starts an H-bomb bomb blast. The Los Alamos simulation showed the second step, when a burst of radiation from the plutonium ignites the fuel that gives a hydrogen bomb its big blast.

Nuclear weapons scientists in the past have devised two-dimensional computer simulations. They then built bombs and triggered them underground to check their theories.

But the United States, as part of an international arms control effort, stopped underground testing in 1992.

Since then, the nation's nuclear lab scientists have been working to develop faster computers and better simulations to replace the information they once received from underground tests.

A key problem was how to simulate the complex whorls and eddies of materials mixing as they are compressed.

Tackling the problem was impossible until a new supercomputer was deliver to Los Alamos lab in 1998, said Bob Weaver, test leader. The computer is capable of performing 1.6 trillion calculations per second.