co-propagating to the ion beam, respectively. The so-called “specific difference”, a weighted difference between the hyperfine transition energies in hydrogen-like and lithium-like ions, provides the means [...] sufficient amount of hydrogen-like 208 Bi 82+ , about 10 5 ions, to observe for the first-time ever the laser resonance signal of a highly-charged ion of an accelerator-produced radioactive isotope. The results [...] ca. 30 min. The ground-state hyperfine splitting structure in heavy hydrogen-like and lithium-like ions resides in the visible and the infrared part of the electromagnetic spectrum, respectively. Even though