Because you are using two positively charged nuclei you must have a lot of heat to overcome the repelling nature. At the moment on earth we cannot get to these temperatures - therefore at this present time it is not used.
Now nuclear fusion is not totally controlled at industrial scale.
Nuclear fusion is used only in experimental installations.
in nuclear fusion bombs
Bombs.
In test reactors.
Fission. Fusion has never been used on Earth, except for nuclear weapon tests.
nuclear fusion
Nuclear fusion is not used for any purpose at present, it is still in the experimental phase
Nuclear fusion is used only in experimental installations.
in nuclear fusion bombs
Nuclear fusion.
In test reactors.
Bombs.
nuclear fusion
Nuclear fusion has been used for nuclear transformation, which is the production of new materials by fusion, and for the type of specific type of transformation called nuclear synthesis, which is the production of materials not normally found in nature. It has been used in nuclear bombs, specifically fusion bombs or hydrogen bombs. There is hope that nuclear fusion can be used to provide power for generation of electricity, though this has not yet been achieved in a practical system. There is a link below to an article on nuclear fusion.
Both are used.
deuterium, and tritium
Nuclear fusion.