The energy spectrum of 0.16 to 3 MeV electrons during solar quiet times

New observations of the quiet-time energy spectrum of 0.16- to 3-MeV electrons have been made with an electron/isotope spectrometer launched on IMP-7 on Sept. 22, 1972. Recent measurements of quiet-time electrons in this energy range by other groups have resulted in spectra differing by more than an order of magnitude in intensity. A minimum quiet-time flux level similar to the lowest previously reported spectra and consistent with an extrapolation of the spectrum measured at higher energies is found. A galactic secondary source of knock-on electrons is consistent with these results, provided that there is negligible solar modulation. Although not required, other recently suggested sources may also contribute to the observed fluxes.