He is particularly remembered for his contributions to research in nuclear physics. In 1926, together with Merle Tuve and Lawrence Hafstad, he constructed a Van de Graaf generator for the Carnegie Institute. Ten years later he did the same for Chr.
Michelsen Institute (Chartered Management Institute) in Bergen.
In the early stages of European Organization of Nuclear Research, Dahl was invited to participate and finally in 1952 to lead the Proton Synchrotron Group"s work to which his contribution had a definitive role.