Neutrino Recoil Spectrometer. Investigation ofA37

A neutrino recoil spectrometer has been constructed. The recoil momentum and the charge distribution of the recoil ions from the $K$ capture of ${\mathrm{A}}^{37}$ has been studied. The results are: neutrino energy, (812±8) kev; recoils of charge 1, (26±3) percent; recoils of charge 2, (13±4) percent; recoils of charge 3, (38±4) percent; recoils of charge 4, (18±2) percent; recoils of charge 5, (4±1) percent; and recoils of charge 6, (1±1) percent. Furthermore, the average momentum of the electrons emitted during the ionization of the recoils is 69±1 gauss-cm. The most energetic Auger electrons have a momentum of 162±4 gauss-cm and they occur in (65±5) percent of the decays.