The United States has completed its first test in a new line of experiments aimed at achieving nuclear fusion "ignition" using a giant laser array at the Lawrence Livermore National Laboratory in California, the U.S. National Nuclear Security Administration announced yesterday (see GSN, Oct. 1).
The successful test at the laboratory's National Ignition Facility focused one megajoule of energy on a pellet containing a combination of tritium, deuterium and hydrogen. The fuel blend was intended to enable the most comprehensive physics, a needed milestone in efforts to achieve ignition, the nuclear agency said (U.S. National Nuclear Security Administration release, Oct. 6). The pellet's temperature was reduced to minus 425 degrees Fahrenheit for the Sept. 29 test, the Contra Costa Times reported.
The energy of the facility's 192 lasers on the gold-coated pellet prompted the release of 1,000 times more neutrons than the site's previous experiments; such particles are expected to power future ignition tests, according to the newspaper (Suzanne Bohan, Contra Costa Times, Oct. 6).
Various systems under review performed together as expected in the test, which involved 26 target diagnostics, according to an NNSA press release. The process under investigation is mainly intended to help measure the safety and dependability of U.S. nuclear weapons, but it could also have energy and other applications.
“From both a system integration and from a physics point of view, this experiment was outstanding,” National Ignition Facility Director Edward Moses said in a statement. “This is a great moment in the 50-year history of inertial confinement fusion. It represents significant progress in our ability to field complex experiments in support of our NNSA Stockpile Stewardship, Department of Defense, fundamental science and energy missions” (U.S. National Nuclear Security Administration release).