Prospects for a day-nightCl37solar-neutrino oscillation experiment

If neutrino oscillations in the solar interior are responsible for the suppressed ${}_{}{}^8{}_{}{}^{}\mathrm{B}$ solar-neutrino flux measured by the Homestake ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ detector, then for certain values of neutrino mass difference and mixing angle, distinct day-night differences in the counting rate are expected due to propagation effects in the Earth. We describe the plans to measure day-night variations with the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ detector, and present the results of calculations of ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ detector sensitivity and expected results.