view Abstract Citations (40) References (26) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Primary Cosmic-Ray Electron Spectrum Near Solar Minimum L'Heureux, Jacques Abstract Two balloon flights were made from Fort Churchill, Manitoba, in the summer of 1965 to continue our investigation of the flux and energy spectrum of the primary cosmic-ray electron component. The spectrum was studied for energies from 20 MeV to 5.5 BeV. Above 1.2 BeV, the differential energy spectrum can be represented by a power la of the form dJ/dE = (48 + 15)E-(2 110 3) electrons . For energies below 1 BeV the spectrum becomes flatter (slope <= 1.6). Between 20 and 270 MeV the total flux rather than the differential flux has been measured. Its value is 180 + 30 electrons . A comparison of our results with data at higher energies obtained by other authors indicates that the spectrum is steeper above 10 BeV ( = 2.45). Our data are also compared with the results obtained from the observations of the non-thermal radio emission from high galactic latitudes. The electron energy spectrum obtained in this experiment is, for energies greater than 1 BeV, in agreement with the spectrum of galactic electrons as derived from the radio-noise measurements. Below 1 BeV the measured electron energy spectrum is flatter than would be predicted on the basis of the radio-noise frequency spectrum for frequencies less than 50 Mc/s (corresponding to electrons below 1 BeV). This might be an indication that solar modulation, even near solar minimum, affects the electron spectrum measured at Earth. The measurements were carried out using a counter system A total-absorbtion lead-glass Cerenkov counter was used to obtain the energy of the electrons Low-energy protons were rejected by the use of a gas (erenkov threshold counter. Guard counters served to identify high-energy protons. Publication: The Astrophysical Journal Pub Date: May 1967 DOI: 10.1086/149162 Bibcode: 1967ApJ...148..399L full text sources ADS |