[noobermin]

You don't use the ignition of one pellet for the next...each pellet ignites itself.

It isn't a nuclear fission reaction where it is a chain reaction between pellets. Each pellet interaction produces energy, and you capture that energy. It is ignition for the pellet, not other pellets in the machine. The boiling of water thankfully happens on a much longer timescale, being accumulationf of energy of many pellets over a few cycles.

[scythe]

The pellets produce a net energy release larger than the energy used by the laser. This energy gain is called "ignition" in fusion parlance. A fuel pellet does not ignite itself — otherwise, they would be destroyed as soon as they are produced, like the critical ball in a nuclear warhead. That's what I was saying from the beginning: the laser does not function like the spark plug on a car engine; it is required for every ignition. It's pretty clear if you go back and read the analogy I initially responded to.