Ac. Cummings et al., DISTANCE TO THE SOLAR-WIND TERMINATION SHOCK AND THE SOURCE FLUX OF ANOMALOUS COSMIC-RAYS DURING 1986-1988, J GEO R-S P, 99(A6), 1994, pp. 11547-11552
We use observations of the intensity of anomalous cosmic ray helium an
d oxygen in the outer heliosphere near the last solar minimum period,
in conjunction with solar observations of the tilt of the neutral curr
ent sheet, to estimate that the solar wind termination shock was at 67
+/- 5 AU during the time period 1986.7-1988.5. We find the source flu
x of anomalous cosmic rays at the shock to be 1.7 +/- 0.3 (M2 s sr MeV
/nucleon)-1 for 7.1-17.1 MeV/nucleon anomalous cosmic ray oxygen and 4
.3 +/-0.8 (M2 s sr MeV/nucleon)-1 for 31-57 MeV/nucleon anomalous cosm
ic ray helium. We also estimate a source flux of anomalous cosmic ray
hydrogen of 2.3 +/-0.6 (m2 s sr MeV)-1 at 134 MeV. The resulting energ
y density of anomalous cosmic rays at the solar wind termination shock
is approximately 0.03 eV/cm3, approximately 2% of the energy density
of the solar wind at 67 AU.