Collinear laser spectroscopy of 178m2Hf

With the production of micro-weight quantities of the nucleus 178m2Hf (T1/2 = 31 y, Iπ = 16+) at JINR in Dubna, it was been possible to produce mass separated fast atomic beams at the PARIS mass separator at CSNSM in Orsay. We have assembled apparatus to perform collinear laser spectroscopy on the atomic Hf beam to measure the nuclear moments μI and Qs and the isomeric shift (from which we can extract the change in mean square nuclear charge radius) of this isotope. Initial measurements using the 6s23P2 -> 6s6p 1P1 transition (λ=572 nm) resulted in detection of three of the nine hyperfine components of the Hf isomer. We have also made complementary measurements on the stable isotopes 177,179Hf allowing us to extract the A and B factors for the initial and final states of the transition. Recent modifications of the apparatus have improved the signal to background ratio from 20 to 500. We expect this will allow us to measure all the lines in the hyperfine spectrum in an upcoming experiment. (author)