MEASUREMENT OF THE ELECTRIC DIPOLE POLARIZABILITIES OF ALKALI HALIDE DIMERS, AND DOUBLET-P(1/2) INDIUM AND THALLIUM

An electric field deflection technique has been used to obtain the average dimer polarizabilities of all the alkali halides, and the scalar ('2)P(, 1/2) polarizabilities of indium and thallium. The experimental procedure consisted of passing a well collimated effusive beam through a region of inhomogeneous electric field and analyzing the deflected beam pattern, with respect to the undeflected beam shape, at the detector.;A second method, employing a C.D.C. Cyber 360 computer, comprizes a quantitative analysis of the monomer and dimer deflections in which part of the actual deflected beam shape is used.;Our results are compared with the polarizability values obtained from a simple 'mass-spring' model for the dimer which employs calculated (and experimental) vibrational frequencies and effective ionic polarizabilities from various dimer models.;In addition to an electric deflection measurement, and E-H gradient balance technique was also employed for the indium and thallium ('2)P(, 1/2) measurements. This method consisted of balancing the magnetic dipole force for negative magnetic substates against the induced electric dipole force in a region where simultaneous and congruent inhomogeneous electric and magnetic fields are estab- lished. These measurements were normalized to an m = -3 substate of Cs whose polarizability is known to within (.5%).;The beam deflections were analyzed in two ways. One method consisted of normalizing the deflections by comparing the experi- mental deflections to those obtained from atomic lithium, whose polarizability is known to within 2%. The normalization reduces the polarizability determination to the ratio of measured line slopes. This procedure lessens systematic errors resulting from a lack of detailed information concerning field variations along the beam path within the interaction region.;The results of our electric deflection and E-H gradient balance measurements for these atomic systems were (UNFORMATTED TABLE FOLLOWS).;In Tl.;10.18 (+OR-) 1.2 (ANGSTROM)('3)) 7.6 (+OR-) 0.8 (ANGSTROM)('3).;(TABLE ENDS).;These values compare extremely well with the recent calculation for Tl of Flambaum and Sushkov (7.11 (ANGSTROM)('3)) and that of Liberman and Zangwill for In (9.66 (ANGSTROM)('3)) and Tl (7.74 (ANGSTROM)('3)).