We saw that, on Earth, the number flux of solar neutrinos from the p-p chain is 6.7E10 s-1 cm-2. Other nuclear reactions in the Sun supplement this neutrino flux with a small additional flux of higher-energy neutrinos. A neutrino detector in Japan, named Super Kamiokande, consists of a tank of 50kton of water, surrounded by photomultiplier tubes. The tubes detect the flash of Cerenkov radiation emitted by a recoiling electron when a high-energy neutrino scatters on it. Calculate the detection rate for neutrino scattering in events per day, if 10-6 of the solar neutrinos have a high enough energy to be detected by this experiment, and each electron poses a scattering cross section=10-43 cm. Hint: Consider the density of neutrino targets "seen" by an individual electron, with a relative velocity of c between the neutrinos and the electron, to obtain the rate at which one electron interacts with the incoming neutrinos, and multiply by the total number of electrons (I've already done this: 1.4E34 electrons) to obtain the rate in the entire detector.

We saw that, on Earth, the number flux of solar neutrinos from the p-p chain is 6.7E10 s-1 cm-2. Other nuclear reactions in the Sun supplement this neutrino flux with a small additional flux of higher-energy neutrinos. A neutrino detector in Japan, named Super Kamiokande, consists of a tank of 50kton of water, surrounded by photomultiplier tubes. The tubes detect the flash of Cerenkov radiation emitted by a recoiling electron when a high-energy neutrino scatters on it. Calculate the detection rate for neutrino scattering in events per day, if 10-6 of the solar neutrinos have a high enough energy to be detected by this experiment, and each electron poses a scattering cross section=10-43 cm. Hint: Consider the density of neutrino targets "seen" by an individual electron, with a relative velocity of c between the neutrinos and the electron, to obtain the rate at which one electron interacts with the incoming neutrinos, and multiply by the total number of electrons (I've already done this: 1.4E34 electrons) to obtain the rate in the entire detector.