Shiva moves closer to laser fusion

In recent months, the 20‐armed Shiva laser system at the Lawrence Livermore Laboratory has attained a significant milestone on the road to the development of a laser‐fusion reactor. The Livermore group has reported that with target pellets of classified design Shiva has driven the deuterium–tritium fuel inside the pellets to between 50 and 100 times its liquid density. (With unclassified ablative targets they report achieving 10 to 20 times liquid density.) One hundred times liquid density is only an order of magnitude short of the densities that will be needed to achieve “scientific break‐even.” This goal, namely the release of as much fusion energy as the lasers deliver to the target (or the somewhat more modest goal of thermonuclear ignition), may well be achieved by Nova, the next generation laser system at Livermore, on which construction began in May.