We use a configuration-mixing quasiparticle Tamm-Dancoff approximation to calculate the expected event rate for an ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$ solar neutrino detector. Our cross section for ${}_{}{}^8{}_{}{}^{}\mathrm{B}$ solar neutrinos is 2.2×${10}^{\mathrm{-}42}$ ${\mathrm{cm}}^2$ [corresponding to about 13 solar neutrino units (SNU) in the standard solar model], a factor of more than 3 below an estimate by Haxton. This value may increase by about 30% when quadrupole correlations are included. The cross section for ‘‘Be neutrinos is 2.0×${10}^{\mathrm{-}45}$ ${\mathrm{cm}}^2$ (9.4 SNU), in agreement with a calculation by Dellagiacoma and Iachello. The total event rate per nucleus from all solar neutrinos is about 3 times that in ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$.

• Received 11 January 1991

DOI:https://doi.org/10.1103/PhysRevLett.67.426