IV. NUCLEAR MAGNETIC RESONANCE AND HYPERFINE STRUCTURE

New precision measurements of the hyperfine-structure interaction constants in 1 radioactive mercury isotopes by optical detection of Zeeman level crossings have been made. The magnetic fields at which the various crossings were observed are shown in Table IV-1, in terms of measured proton resonance frequencies. These values are still preliminary, since the analysis of systematic errors has not been completed. From the data in Table IV-1, the best values of the magnetic dipole interaction constants (A) and the electric quadrupole interaction constants (B) in the 6s6p 3P 1 state are obtained (Table IV-2). The calculations were carried out on the IBM 7090 computer at the Com-putation Center, M. I. T., by using the program HYPERFINE 3-9.2 The ratio of the previously measured 1 interaction constants for Hg 1 9 5 (9.5 hour) and Hg 1 9 9 (both nuclear spin 1/2) has been calculated to be A1 9 5 ( 3 P 1) f p(195) 1993 = 1. 071925(63). f (199