Sudden change in the nuclear charge distribution of very light mercury isotopes

Abstract

The following quantities have been determined by optical pumping with the spectral line 2537 A ̊ : 183 Hg: I = 1 2 , μ I = 0.513(9) nm , isotopic shift ( 183 Hg − 204 Hg) = 18.9(8) GHz; 185 Hg: I = 1 2 , μ I = 0.449(4) nm , isotopic shift ( 185 Hg − 204 Hg) = 19.2(4) GHz . The siotopic shifts for 183,185Hg deviate very strongly from an extrapolation from the heavier mercury isotopic (including 187Hg). This indicates that a large increase in the effective nuclear volume of Hg occurs in going from N = 107 to N = 105.