Annealing of radiomanganese in irradiated potassium permanganate under different circumstances

The annealing of 52Mn, 54Mn and 56Mn was studied in irradiated solid KMnO4. The retention after annealing was found to be strongly dependent on the pretreatment of the crystals, on the absorbed dose, but not on the isotope formed. The retention at room temperature was hardly affected and showed a nearly constant value. It appeared that gamma irradiation before activation or after activation counteracts the annealing, leaving the unannealed fraction unaffected. Irradiations with charged particles, followed by neutron irradiation after the decay of the original 56Mn, showed a different behaviour for the different radiomanganese nuclides. (author)