Highly charged ions for atomic clocks and search for variation of the fine structure constant

الأصل · EN

We review a number of highly charged ions which have optical transitions suitable for building extremely accurate atomic clocks. This includes ions from Hf¹²⁺ to U³⁴⁺, which have the 4f¹² configuration of valence electrons, the Ir¹⁷⁺ ion, which has a hole in almost filled 4f subshell, the Ho¹⁴⁺, Cf¹⁵⁺, Es¹⁷⁺ and Es¹⁶⁺ ions. Clock transitions in most of these ions are sensitive to variation of the fine structure constant, α (α= e²/ℏ c). E.g., californium and einsteinium ions have largest known sensitivity to α-variation while holmium ion looks as the most suitable ion for experimental study. We study the spectra of the ions and their features relevant to the use as frequency standards.