Active ion tracer experiments attempted in conjunction with the ion composition experiment on GEOS-2

To date, six ion injection/tracer experiments have been attempted in conjunction with the GEOS-2 Ion Composition Experiment: three rocket borne Ba shaped-charge releases (Porcupine 3 and 4 and Ba-GEOS), one Li release, and two periods of operation of the Xe⁺ accelerator on the SCATHA satellite. All six attempts have yielded null results for ion detection at GEOS-2 with a 2σ upper limit on ion fluxes of ≈ 10²/cm² s sr. Three of these attempts were unlikely to have succeeded, however, due to poor conjugacy conditions or to low ion source intensity.