> If we will have cheap source of muons, we can change equation.
You can make them but the cost in energy is exactly the problem: you will be spending money on energy to make muons at a considerable loss due to the inefficient ways in which we know how to make them (proton beams, which require a huge amount of energy to create), resulting in an insignificant number of particles. If your goal is to get net energy out it would be good to keep an eye on process efficiency from the beginning. Starting off with a billion to one or so conversion loss for step one raises the bar for the subsequent steps considerably.
> Sadly, we have no such cheap source of muons, AFAIK.
We have tons of free high-energy radiation in space. LENR can be impractical on Earth, but be practical on Mars, or on a space station, or in Van Allen belts. Mars is very cold, but constantly bombarded by cosmic rays, because it lacks magnetic shield. Thin atmosphere allows much larger flux of particles with lower energies to reach ground. It may work, if lattice will be exposed to the cosmic rays. LENR can be used here as lightweight source of heat for domes.
You can make them but the cost in energy is exactly the problem: you will be spending money on energy to make muons at a considerable loss due to the inefficient ways in which we know how to make them (proton beams, which require a huge amount of energy to create), resulting in an insignificant number of particles. If your goal is to get net energy out it would be good to keep an eye on process efficiency from the beginning. Starting off with a billion to one or so conversion loss for step one raises the bar for the subsequent steps considerably.
> Sadly, we have no such cheap source of muons, AFAIK.
Indeed we do not, and that's pretty logical.