OK, but MY point was that the "ignition" being referred to in ICF is a chain reaction, and not just "burning" at some low rate of consumption, as in the sun:
The energy released by these reactions will then heat the surrounding fuel, and if the heating is strong enough this could also begin to undergo fusion.The aim of ICF is to produce a condition known as "ignition", where this heating process causes a chain reaction that burns a significant portion of the fuel.
"These reactions" refers to the fusion caused by the laser heating, which plays the role of the fission "trigger" in an H-bomb, as I understand it. This is thermonuclear ignition, like an H-bomb, and like a pair instability supernova, but not like the sun.
Simply because only ~300W/m^3 are being produced, that doesn't mean the reaction is not sustaining itself! Remember even though only ~300W/m^3 are produced per second, a cubic meter of matter in the center of the sun has an energy density of around 10^16 J/m^3. That's ignited plasma, no question about it.
And keep in mind, when you consider the 'Q' that various projects are envisioning, fusion reactors will be using most of their energy to maintain confinement (fed back into the lasers or magnetic fields); they are not going to be exploding like a thermonuclear weapon. They will have many times better yields than the P-P fusion chain, but the definition of ignition doesn't change. It's just the difference between burning incense or gasoline. At some point, either fuel "catches" and the oxidation becomes hot enough to maintain the kindling temperature for more oxidation to occur. Only difference is, it's nuclear chemistry instead of atomic chemistry.