One year later, the Sudbury Neutrino Observatory (SNO) started collecting data. That experiment aimed at the B solar neutrinos, which at around 10 MeV are not much affected by oscillation in both the Sun and the Earth. A large deficit is nevertheless expected due to the Mikheyev–Smirnov–Wolfenstein effect as had been calculated by Alexei Smirnov in 1985. SNO's unique design employing a large quantity of heavy water as the detection medium was proposed by Herb Chen, also in 1985. SNO observed electron neutrinos, specifically, and all flavors of neutrinos, collectively, hence the fraction of electron neutrinos. After extensive statistical analysis, the SNO collaboration determined that fraction to be about 34%, in perfect agreement with prediction. The total number of detected B neutrinos also agrees with the then rough predictions from the solar model.