High-resolution laser spectroscopy of singly charged natural uranium isotopes.

High-resolution collinear laser spectroscopy has been performed on singly charged ions of U at the IGISOL facility of the Accelerator Laboratory, University of Jyväskylä, in Finland. Ten ionic transitions from the and ground and first excited states were measured in the 300 nm wavelength range, improving the precision of the hyperfine parameters of the lower states in addition to providing newly measured values for the upper levels. Isotope shifts of the analyzed transitions are also reported for U with respect to U.