The radiation chemical yields of the Fricke dosimeter have been determined for incident nickel and uranium ions with energies of up to 470 and 3780 MeV, respectively. Track segment yields have been determined from the observed energy dependences. Experiments utilizing both aerated and deaerated solutions indicate that at the very high values of linear energy transfer (LET) exhibited by these ions in water (a maximum of 5000 and 17 000 eV/nm, respectively) a significant fraction of radicals escape from the track. The radiation chemical yield of H atoms for both ions is found to be similar to 10% of the value with fast electrons. The data also suggest that there is a substantial yield of an oxidizing species produced by particles of very high LET. A comparison of the results with particles of lower LET is made.