Vannak
Your first point is wrong. The sun has additional "free" pressure put onto it by gravity which is a massive part of it's energy input. We don't have this, hence the statement "It takes more energy than
we can get out of it."
Wrong. Hydrogen fusion bombs, anyone?
The only struggle with a fusion reactor is to keep it under control in a way that still produces a net gain of useful energy.
Suicidesoldier#1
Man, so an isomer of krypton fusion is really just a pipe dream then D:
Is there anyway it's more practical, such as with a lower starting temperature, or being more "unstable" and likely to fuse etc.
The problem with hydrogen fusion seems to be we can't get the pressure or temperature high enough to start fusion on a large enough piece of mass with the precision that's required of lasers.
But if we threw some stuff in there, that was already releasing all kinds of energy, to start up fusion instead of having to use super lasers, it might be a good enough catalysts to start one reaction, which could then go on to use raw fusing 600 million degree fuel as an ember so to speak to light up more fusion reactors around the world and back up ones and whatnot etc.
We make a small one, transport it to a larger one, throw some of the blazing hot fuel in there etc.
All you have to do is keep adding fuel and it would be self sustaining; in case one went out, you could use another and siphon off a small amount of blazing hot material to start the next one etc.
Maybe, but think about it this way: any heat 'wasted' on fusing helium atoms into lithium or whatever is heat we might have been able to extract in the form of useful energy if only we had more hydrogen to spend it on instead.
There's probably an equilibrium point farther down the periodic table from iron that is the optimum for some function of re-using fuel while also extracting the maximum heat.