Evolution of the Energy Spectra of Anomalous Cosmic Rays in the Outer Heliosphere and the Distance to the Solar Wind Termination Shock

Using data from the Voyager 1 and 2 (Vl and V2) spacecraft, we examine the energy spectra of anomalous cosmic rays (ACRs) for three time periods in 1993 - 1994. We use a spherically-symmetric model of the propagation of ACRs in the heliosphere to derive the energy spectrum of ACRs at the solar wind termination shock and the shock's location. We find that in late 1994 the shock strength has a value of 2.40 ± 0.12 and is located at 84.2 (-2.2, +2.6) AU.