As the key material bearing the future energy needs of humanity, helium-3 fusion is mainly divided into two types:
helium-3 with deuterium fusion, and helium-3 with helium-3 fusion.
The former is known as Second-Generation Nuclear Fusion Technology, and the latter as Third-Generation Nuclear Fusion Technology.
Deuterium and tritium are both isotopes of hydrogen, with only one proton, while helium-3 has two protons; thus, the more advanced the fusion technology, the greater the mass of the reactants.
But don't underestimate the difference in mass of just one proton; the conditions required for ignition are completely different, and the difference is tremendous.
The lighter the nucleon, the easier the reaction; conversely, the difficulty dramatically increases.
External media often deliberately emphasize the ignition temperature of controlled nuclear fusion test reactors; this is actually just one aspect and it isn't the absolute condition for successful ignition.
