I think it is safe to assume that NIF and the approach they use will never become a practical fusion power plant , so given a layman can understand this I think they know they are working for a totally different purpose...
Even if they manage to get more energy out (electrical) from each shot and pellet than they put in via the lasers , which is I'd say rather impossible given the layout of the pellet fusion chamber and not close to breakeven for laser energy in - thermal energy out , they would still succumb to a very slow repetition rate since the pellet is a physical ball which needs to be replaced , not to mention what
@mfb said about the time the lasers take to cool, and even if they use different lasers the power supply would probably need some time to "charge up" given how much energy it takes to drive a single shot.
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@mfb can maybe also answer , if those laser crystals need so much time to cool after a single shot , and the shot itself lasts (ns?) then how in the world they don't crack or explode to pieces at the moment of the pump? What is the rate of temp increase under such a fast and powerful energy discharge? Or is it that they simply use a lot of parallel smaller ones and then combine the beams?But one thing somewhat intrigues me , what new physics do they hope to see at NIF with regards to H bombs and thermonuclear fusion that hasn't already been found by theory and other fusion experiments and the numerous H bomb detonations both by US and USSR alike?
One thing I can imagine is a much better access to the process of radiation ablation and implosion , a process that happens similarly in the H bomb only the source of photons is a laser instead of an A bomb and the radiation wavelength is I think higher at NIF.
So at NIF they can utilize the open geometry and poke all kinds of sensors and cameras to capture the implosion fusion, I think even more than they can in Sandia's Z machine , since that approach has a metal liner.
on it's laser and laser based fusion physics and isn't tasked with inventing practical fusion reactors as others are. But the above quote begs the obvious question if 250 kJ of the output energy of one shot could be diverted to the next shot in a suitable design forming a controlled chain reaction and if so what would be the cost of creating a pellet vs. the value of the ~1 MJ of energy output even assuming the conversion was fairly efficient?
