Nuclear Magnetic Quadrupole Moment Research Articles

Nuclear Moments and Intermediate Coupling

The effect of intermediate coupling on the calculation of the nuclear moments of the rare earths from analyses of hyperfine structure is examined. It is shown that the observed hyperfine splittings may be satisfactorily interpreted as due to the interaction of the spin and orbital moments of 4f electrons with the nuclear magnetic and electric quadrupole moments. The interaction of the electron-spin moments with the nuclear magnetic moment is shown to be very sensitive to the form of the coupling. The consistency of the measurements of nuclear moments by atomic-beam and paramagnetic resonances is discussed. Instead of using the more usual spin-Hamiltonian formalism, the matrix elements of the interactions are calculated explicitly in terms of the actual quantum numbers of the states involved. Calculations are presented for Pr141 and Ho165.

Atomic-Beam Measurement of the Hyperfine Structure and Nuclear Moments of Iodine-131

The nuclear magnetic dipole and nuclear electric quadrupole interaction constants a and b were measured in 8-day I/sup 131/ by an atomic beam magnetic resonance experiment. The results were a = 575.903 plus or minus 0.007 Mc/sec, b = 578.866 plus or minus 0.075 Mc/sec. The zero-field hyperfine splittings computed from these values of a and b were DELTA nu (5,4) = 3292.99 plus or minus 0.09 Mc/sec, DELTA nu (4,3) = 2138.22 plus or minus 0.05 Mc/sec, DELTA nu (3,2) = 1314.24 plus or minus 0.07 Mc/sec. The nuclear magnetic dipole moment and nuclear electric quadrupole moment were calculated as mu /sub 131/ = 2.738 plus or minus 0.001 nm, Q/sub 131/ = --0.41 plus or minus 0.01 x 10/sup -24/ cm/sup 2/. The value of mu /s ub 131/ obtained differed slightly from that obtained by other workers, whereas the value of Q confirmed an earlier measurement made by a different method. (auth)

Hyperfine Structure and Nuclear Moments of Bromine-82

The nuclear spin, the magnetic dipole, and the electric quadrupole interaction constants have been measured for 35-hr bromine-82 by the method of atomic beams. The results are $I=5$, $|a|=205.04\ifmmode\pm\else\textpm\fi{}0.05$ Mc/sec, $|b|=870.7\ifmmode\pm\else\textpm\fi{}0.9$ Mc/sec, and $\frac{b}{a}=\ensuremath{-}4.246\ifmmode\pm\else\textpm\fi{}0.001$.The nuclear magnetic and electric quadrupole moments obtained from these values of $a$ and $b$ are $|\ensuremath{\mu}|=1.6264\ifmmode\pm\else\textpm\fi{}0.0005$ nm, and $|Q|=0.76\ifmmode\pm\else\textpm\fi{}0.03$ barn. While only the relative sign of $\ensuremath{\mu}$ and $Q$ is determined, both $\ensuremath{\mu}$ and $Q$ are almost certainly positive. A new method for solving the interaction Hamiltonian with magnetic field, for arbitrary $I$ and $J$, by using an IBM 650 computer, is described.

Hyperfine structures of the resonance lines of indium 115

The hyperfine structures of the two visible resonance lines of the arc spectrum of indium 115 have been measured in the absorption of a multiple atomic beam of high collimation by means of a double Fabry-Perot interferometer; the combined instrumental and Doppler width of the absorption lines was less than 5 mK (0∙005 cm -1 ). By taking the necessary precautions to avoid systematic errors and by measuring a large number of different interferograms to reduce the random error it has been possible to measure the h. f. s. of the lines 4101 and 4511 Å with an accuracy sufficient to allow the intervals of the terms 5 2 P 3/2 , 5 2 P ½ and 6 S ½ to be determined with a probable error of 0∙07 mK. The ratios of the three h. f. s. intervals of the term 5 2 P 3/2 are in agreement, within the limits of the probable error, with those required on the assumption that the h. f. s. is due to nuclear magnetic dipole and electric quadrupole moments; the value found for the dipole coupling factor, A , is 8∙083 ± 0∙01 mK and for the quadrupole coupling factor, B , is 15∙10 ± 0∙1 mK. A comparison is made between the values of the h. f. s. intervals found in this work and those found by microwave measurements, since one of the principal aims of this research is to test the agreement between the results found by optical spectroscopic methods and by microwave methods.