Ignition—the process of releasing fusion energy equal to or greater than the amount of energy used to confine the fuel—has long been considered the “holy grail” of inertial confinement fusion science. A key step on the way to ignition is to have the energy generated through fusion reactions in an inertially confined fusion plasma exceed the amount of energy deposited into the deuterium–tritium fusion fuel and hotspot during the implosion process, resulting in a fusion fuel gain greater than unity. Read more »