HYPERFINE-STRUCTURE IN THE CONFIGURATIONS 4F(4)6S(2) AND 4F(4)5D6S OF ND-I

The high resolution laser-atomic-beam technique was used to investigate the hyperfine structure in Nd I 4f46s2 5I, 5F, 5S and 4f45d6s7L, 7K, 7I, 7H. The metastable states were populated by an arc discharge burning in the atomic beam. The measured hyperfine constants A and B of the levels of 4f46s2 and 4f45d6s allow a parametric analysis to be performed using the effective tensor operator formalism. The experimental radial integrals of the 4f and 5d electrons fit with those of the other lanthanides. The 4f radial integrals are in agreement with values of optimized Hartree-Fock-Slater calculations. The spectroscopic quadrupole moments of Nd-143 and Nd-145 are deduced from the 4f parameters: Q(I) = -0.610(21) b and -0.314(12) b, respectively. The Q(I) resulting from the 5d parameter are in satisfactory agreement with these values. The hyperfine anomaly due to the s electron in 4f5d 6s amounts to about 1%.