Galactic Cosmic-ray Electrons in the Heliosheath from Voyager 1 Observations

Voyager 1 (V1) crossed the termination shock of the solar wind on 16 December 2004 at a distance of 94.0 AU from the Sun and traversed the heliosheath until crossing its boundary, the heliopause, on 25 August 2012 at a distance of 121.6 AU from the Sun. During this traversal, the intensity of galactic cosmic ray (GCR) particles penetrating the High Energy Telescopes on the Cosmic Ray Subsystem (CRS) experiment, consisting primarily of >70 MeV protons, increased steadily by a factor of 2, with a final jump up by another factor of 1.3 near and at the heliopause. The total intensity change in the heliosheath accounts for nearly half the intensity change observed by V1 since launch. The situation with GCR electrons has not been as clear due to the presence of considerable background in The Electron Telescope (TET) on CRS during the early part of the traversal of the heliosheath. In this paper we use multiple methods to infer the background in TET and derive GCR electron intensities with 5 to 74 MeV at several intervals in the heliosheath. Implications of the results for solar modulation and other studies will be discussed. Voyager data analysis is supported by NASA Grant NNN12AA01C.