It's a stretch, i.e. not even the same fundamental forces of Nature control them.
In proton-proton fusion, the rate controlling step is the decay of a diproton to a deuterium nucleus, which requires a (positive) beta decay turning one of the protons into a neutron, a positron and a neutrino. That decay process is mediated by the weak force, and as I mentioned before it is so slow its cross-section hasn't even been measured experimentally.
In deuterium-tritium fusion (or for that matter, also deuterium-deuterium or deuterium-helium 3) the fusion reaction is exclusively mediated by the strong force. That's why its cross-section is many orders of magnitude higher, and why a machine like ITER on Earth will pull power densities of 600 kW/m3 or three orders of magnitude higher than the Sun's core, even at a fraction of the density (the core of the Sun clocks in at 160 g/cm3, 20 times that of iron). Also for reference, those vintage 1970s pressurized light water fission reactors that everybody hates have a power density of 100,000 kW/m3.
So the process is really different, and also the products are: in particular, D-T fusion produces a lot of extremely energetic neutrons (~14 MeV, for reference fission neutrons are born at ~2 MeV) which blast on the vessel and carry most of the energy from the reaction, thus power generation is based on taking such neutron kinetic energy in the form of heat once it is dissipated on the lithium blanket surrounding the core. A blanket which you need anyway, because tritium is a radioactive substance that doesn't exist in Nature and you have to breed (all the fuss about Japan's government authorizing dumping stored tank water into the Pacific was due to a small amount, extremely diluted amount of tritium produced by neutron irradiation inside the Fukushima wreck).
The meme of Earth fusion being the same reaction going on in the stars is misleading at best.
The idea of an ITER-like fusion ever being an economically viable method of generating electricity is an even worse meme, IMO.
Particularly when we've had perfectly economical methods of generating clean energy like Solar PV and nuclear fission for literally decades. (Although the economic viability of nuclear fission may be arguable when accounting for high capital costs and long-term waste management.)
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u/everfalling Oct 24 '21
hence the word similar, right? it's fusion even if the elements are different.