Electrodisintegration of 3He

The continuum spectra of 3He have been measured up to excitation energies of 40 MeV by means of inelastic electron scattering. The experiment was performed at the 140 MeV linear electron accelerator facility of the National Bureau of Standards, Gaithersburg, Maryland. The following incident-electron energies were used: 60, 75, 90, 110 and 120 MeV; the corresponding momentum transfer range was from 0.3 to 1.1 fm-1. Electrons scattered were observed at two angles, 92.60 and 127.70. A gas target pressurized to 10 atmospheres with 3He was used in the experiment. Data were also taken on an empty target of identical construction for subtraction of backgrounds. A Cerenkov counter was used as a back-up detector, in order to reduce the sensitivity of the counting system to background neutrons. The measured spectra were corrected for radiation and ionization effects, and a calculated elastic radiation tail was subtracted from the data, before a bin-by-bin radiation unfolding was applied to the continuum spectra. The unfolded data were presented, and compared with photodisintegration and 1800 electron scattering experiments. The predominant transitions were found to be E1 and E2. Some magnetic strength was also present, but its multipole assignment has not been firmly established. The sharp rise from the p + d threshold observed in this experiment could be explained as a 2S → 2S electric monopole transition, in a simple model of a proton bound to a deuteron