Double-resonance-ionization mapping of the hyperfine structure of the stable Cu isotopes using pulsed narrowband Ti:sapphire lasers

摘要

We present two approaches to enhance the resolving power for measuring hyperfine structure constants using resonance ionization spectroscopy. The first method employs a 2D-resonance ionization spectroscopy scanning technique with pulsed, narrowband Ti:sapphire lasers (1 GHz linewidth), allowing us to resolve hyperfine components that cannot be separated using the standard 1D-scanning method across only one optical transition. In a second refinement, the resolving power is further enhanced through the use of a ring design of the laser cavity. This layout leads to a reduction of the laser linewidth from 1 GHz to below 50 MHz, resulting in experimental linewidths of about 150 MHz. Motivated by the current nuclear physics interest in radioactive Cu isotopes, the hyperfine structure of the 3d(10)4s S-2(1/2) ground state and the 3d(9)4s4p P-4(3/2)o and 3d(10)6s S-2(1/2) excited states in stable Cu isotopes were studied using both approaches. The hyperfine A parameter of the 3d(10)6s S-2(1/2) state was measured with values of 296(18) MHz for Cu-63 and 307(18) MHz for Cu-65.