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In HD+, a proton is replaced by a deuteron, which makes the molecule more accessible in spectroscopic terms.

In the lab, Wu and Shaknov used it to bombard a sheet of copper with deuterons, generating an unstable isotope, Cu 64, as a source of positrons—the antimatter.

In the first step of this fusion process, two protons inside the sun fuse into a deuteron while giving off a neutrino and a positron—the antiparticle of the electron.

To make the deuteron and hydrogen ion orbit under the same conditions, Myers and Fink kept the two in the same electromagnetic trap for weeks at a time.

The deuteron mass, md, is then found in atomic mass units, where one atomic mass unit is defined as one-twelfth the mass of the carbon atom.