The addition of certain solutes to a water Cerenkov detector will introduce new charge-current channels for the detection of ${\nu }_e$'s. The experimental conditions necessary to exploit such signals—large volumes and very low backgrounds—should be reached for the first time in SuperKamiokande and the Sudbury Neutrino Observatory. I compare some of the more attractive possibilities ( ${}^7\mathrm{Li}$, ${}^{11}\mathrm{B}$, ${}^{35}\mathrm{Cl}$) in terms of counting rate, reliability of the cross section, specificity of signal, and potential for distinguishing competing solutions to the solar neutrino puzzle.

• Received 28 November 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.1562