The Sudbury Neutrino Observatory was designed to operate in three distinct configurations that made use of different techniques for measuring the rate of the neutralcurrent disintegration of deuterium by solar neutrinos. In the third of these phases an array of 3 He-filled proportional counters was deployed in the heavy water, and neutrons from the neutrino-induced breakup of deuterium were detected when they captured on 3 He, liberating 764 keV of energy in the form of ionization of the gas.

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... pects of the analysis of the data from this phase are described, and the results presented. There is good agreement with the results obtained with the other techniques in previous phases, and improved precision on the determination of the "solar" mixing angle.