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Hyperfine Structure of Thallium Bromide

The hyperfine structure of the J  =  2J=2 and J  =  3J=3 rotational states of TlBr has been measured with a molecular‐beam electric resonance spectrometer. Hyperfine transition frequencies were measured under conditions of very weak electric and magnetic fields. The linewidth was 500 Hz. The hyperfine interaction constants have been determined for 205Tl79Br, 203Tl79Br, 205Tl81Br, and 203Tl81Br in the first five vibrational states for J  =  2J=2. In addition, the interaction constants for J  =  3,υ  =  0J=3,υ=0 were determined for Tl79Br and Tl81Br, but it was not possible to resolve the effect of the two thallium isotopes in the J  =  3J=3 state. The spectra measured are well described by a hyperfine Hamiltonian containing the bromine quadrupole interaction, the spin–rotation interactions of both the thallium and the bromine nuclei, and both the scalar and tensor parts of the spin–spin interaction between the nuclei. The dependence of the magnetic hfs constants on vibrational state and on isotopic composition shows good agreement with theory. The magnetic octupole interaction of the bromine nucleus in TlBr is negligibly small, and we find no evidence for nuclear polarization or pseudoquadrupole effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70429/2/JCPSA6-53-4-1525-1.pd

Molecular Beam Measurement of the Hyperfine Structure of 85Rb19F

Radio‐frequency transitions between the hfs levels of the J=1 rotational state in 85Rb19F have been observed using a molecular beam electric resonance spectrometer. From these spectra we have obtained values for the constant eq1Q1, which characterizes the interaction between the electric quadrupole moment of the Rb nucleus with the molecular electric‐field gradient; for the constants c1 and c2 which characterize the magnetic interaction between the Rb and F nuclei, respectively, and the rotational angular momentum J of the molecule; and for the constants c3 and c4 which describe the magnetic coupling of the two nuclear spins. Measurements have been made on the first‐five vibrational states. The results for v=0 areeq1Q1=(−70.342±0.001)MHz,c1=(+0.52±0.02)kHz,c2=(+10.615±0.06)kHz,c3=(+0.80±0.06)kHz,c4=(+0.15±0.05)kHz.Values of these constants for v=1, 2, 3, and 4 are given with somewhat less precision.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69352/2/JCPSA6-45-10-3731-1.pd

Triple Resonance Method for Molecular hfs Spectroscopy: Measurements on 133Cs19F

Three sequential oscillatory fields are employed in a molecular beam electric resonance spectrometer in order to observe molecular hfs transitions which do not obey the criteria for observability in the usual beam apparatus. The triple resonance method has been used to examine the hfs of CsF under conditions of very weak external fields. The method shows considerable promise for the detailed study of molecular hfs when more than one nucleus has a quadrupole moment, and for the observation of transitions at audio frequencies between closely spaced molecular energy levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70906/2/JCPSA6-47-10-3904-1.pd

Hyperfine Structure of Thallium Chloride

The radio‐frequency spectra of TlCl at very weak electric and magnetic fields have been measured with a molecular beam electric resonance spectrometer. From these spectra the hyperfine interaction constants for the four isotopic species of the molecule were calculated. The constants for 205Tl35Cl in the J  =  2,υ  =  0J=2,υ=0 state are: eqQ  =  − 15793.32(50)kHz,cCl  =  1.38(10)kHz,cTl  =  76.35(10)kHz,c3  =  − 0.13(10)kHz,c4  =  − 1.54(10)kHz.eqQ=−15793.32(50)kHz,cCl=1.38(10)kHz,cTl=76.35(10)kHz,c3=−0.13(10)kHz,c4=−1.54(10)kHz. A test was made for the polarization of the chlorine nucleus in the electric field of the molecule by comparing the ratio of the quadrupole interaction constants for 205Tl35Cl and 205Tl37Cl to the ratio of the quadrupole interaction constants for the free chlorine atoms. The agreement of the two ratios is within their uncertainties, thus providing no evidence for a polarization effect. In addition, the dependence of the spin–rotation and spin–spin interaction constants on isotope was found to show good agreement with theory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69724/2/JCPSA6-50-5-2086-1.pd

Raising a Small Flock of Sheep in Ohio

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