Chemical reactions with accelerated ions. Chemical effects following interaction between chromium ions and solid oxyanion systems

Abstract

An electromagnetic isotope separator and a 600 kV ion accelarator have been used for the production of energetic beams of radioactive ⁵¹Cr ions from 5 to 450 keV. The chemical fate of singly-and doubly-charged chromium ions in KClO₄, K₂CrO₄, K₂SO₄, Na₂MoO₄, mixed K₂CrO₄+K₂SO₄ crystals, and mixed K₂CrO₄+K₂BeF₄ crystals have been studied using a tracer technique. A comparison between the distribution of ⁵¹Cr atoms among the possible chemical forms produced with accelerated ⁵¹Cr ions and chemical effects of recoils from nuclear reactions in K₂CrO₄, and in the mixed crystal systems show similar features. Evidence for the presence of chromous ions in KClO₄, K₂SO₄, and the mixed crystal systems is presented. The chemical distribution of the ⁵¹Cr atoms depends on the chemical composition of the target, the target preparation method, the energy, and the charge of the accelerated ions, and on the dose received. Further evidence for an electronic annealing mechanism for irradiated potassium chromate is obtained.