Electron disintegration of helium between 45 and 100 MeV

The differential cross section of 4He(e,efn)3He:,was measured at five angles over an energy range of 45-100 MeV. Electrons from the National Bureau of Standards 120 MeV, 40 kW linear electron accelerator struck a gaseous-He target. The charged reaction products were detected by 10 lithium drifted silicon detectors cooled to 770K located in the focal plane of the d~ub1e focusing 1200 wedge magnet of the positive ion spectrometer.The amplified pulses from the detectors, after conversion to digital form, were recorded and stored in an IDS 920 computer. The resulting pulse height spectra exhibited distinct peaks corresponding to tritons, deuterons, protons and 3He fs. The data were analyzed using virtual photon spectra to- yield photodisintegration, cross sections corresponding to the reaction 4He (y,h)3He . The resulting differential cross sections are consistent with the form go = A Sin2e(l + ~ cos e). The sin2e