Reducing Background in Laser Spectroscopy Experiments at BECOLA*

A discontinuity is generally observed in trends of mean-square charge radii at the magic numbers.  The discontinuity, however, is missing at the N = 20 neutron magic number for Ar, K and Ca isotopes.  The trend of Sc charge radii across N = 20 is therefore of great interest, as it will show the effect on the missing signature caused by one proton in the 1f_7/2 shell outside the ⁴⁰Ca core.  As a preliminary step towards the investigation, a hyperfine spectrum of stable ⁴⁵Sc was studied using collinear laser spectroscopy techniques at BECOLA at NSCL/MSU to optimize the laser spectroscopy system.  Details of test measurements and results will be discussed.