No, he was one of the people who elucidated the structure of DNA and was awarded a Nobel prize for this discovery in 1962. Maurice Wilkins and Francis Crick also shared the prize with Watson that year.
Francis Crick
1953
James Watson helped to discover the shape of a DNA molecule. A double helix
Nuclear fusion occurs naturally in stars. Artificial fusion in human enterprises has also been achieved, although it has not yet been completely controlled as an energy source; successful nuclear physics experiments have been performed involving the fusion of many different nuclear species, but the energy output is negligible in these studies. Building upon the nuclear transmutation experiments of Ernest Rutherford done a few years earlier, fusion of light nuclei (hydrogen isotopes) was first observed by Mark Oliphant in 1932; the steps of the main cycle of nuclear fusion in stars were subsequently worked out by Hans Bethe throughout the remainder of that decade. (Text taken from Wikipedia.)
James Watson And Frncis Crick
James Watson and Francis Crick discoverd the two strands of nucleotides that form a twisted ladder (double helix) in DNA
James Watson and Francis crick together with Maurice Wilkins announced their discovery of DNA in 1953, winning the Nobel prize in medicine.
James Watson and Francis Crick
28th February 1953
Francis Crick
Sir James Chadwick discovered it in 1932
James Watson and Francis Crick discovered the structure of DNA.