Thermochromatographic separation of no-carrier-added Re-186 or Re-188 fromtungsten targets relevant to nuclear medical applications

The thermochromatographic behavior of no-carrier-added rhenium isotopes and macroscopic tungsten was studied at different temperatures as well as in d ry and watervapor containing (moist) atmospheres of oxygen or air. Due to t he high thermal volatility of HReO4, Re-186/188 can easily be separated fro m tungsten matrices in yields of 65 +/- 15% free from tungsten in less than one hour and in minimum volumes of various solutions. After double neutron capture by W-186, this separation process can be applied to construct a W- 188/Re-188 generator. In addition, the thermochromatographic separation pro cess might be an option to separate no-carrier-added Re-186 after a W-186(p ,n) or a W-186(d,2n) reaction at a small cyclotron.