Hi, my name is John and i’m a hapless high school student.
I’m doing a research project on nuclear physics. Everyone: textbooks, websites, literature, seem to be all over the problem on fission, from atomic theory all the way to the power plant. But noone even knows who DISCOVERED fusion, even though it’s much more powerful than fission. So my question is twofold: who is credited with discovering FUSION and why doesn’t anyone seem to care?
Who discovered fusion? God. No-one else has been able to make it work twice. That’s why you can’t find much about it. Fission is understood, controllable and replicable. That’s why you find so much about it.
Edward Teller and his team are generally credited with the creation of the first hydrogen (fusion) bomb, but I don’t know as you could turn around and say that they “discovered” it. Since fusion is what powers the Sun and stars, I suppose you could argue that God discovered it. 
It was widely known that nuclear fusion powers the stars before fusion bombs or fusion reactors were every created, so it seems the proper question is: Who fisrt figured out that nuclear fusion releases lots of energy, and that it is the process by which the stars work?
That honor would probably go to Sir Arthur Eddington, who was one of the first to postulate the idea in the 1920s. In Some time later, Hans Beth(sp?) clarified this idea a bit more by working out how the specific proces of fusing hydrogen atoms might work.
The discovery of fusion is usually attributed to Oliphant, Harteck and Rutherford in 1934 (*Proc.Roy.Soc.*A 144). They were bombarding heavy water with deuterium nuclei and realised that they were forming helium, together with stuff like neutrons and gamma rays. By all accounts, the paper not only nailed the effect, they realised what they were observing.
Note that this means that the discovery of fusion actually predates that of fission.
The prehistory is somewhat murkier …
Writing in 1939, Chandrasekhar (An Introduction to the Study of Stellar Structure, reprinted Dover, 1957) is interestingly vague about assigning credit here. Writing in the final chapter (p456), he states:
“[A] source of stellar energy … is the transmutation of elements - a suggestion which appears to have been first seriously considered by Harkins, Perrin, Eddington, and, more recently, by Atkinson and Houtermans.”
However in the bibliographical notes at the end of the chapter, he lists his references for this as Eddington (1920), Perrin (1920) and Harkins and Wilson (1915), in that order. Of course, Chandrasekhar had reason to dislike Eddington, so there may be an agenda here. But I’d suspect anybody discussing transmutation in this period probably did have a fusion-like process in mind. One would have to read these papers to be sure.
There’s also the complication that in the 1920s, you get a handful of people believing that they’ve achieved fusion in test-tubes. But such claims were dismissed, forgotten about and only dug up again once “cold-fusion” purported to be doing something very similar.
Bethe proposed the proton-proton chain, the final explanation of how stars get most of their energy, in 1938. Judging by Chandrasekhar’s account the following year, this took a while to be universally accepted.