Lifetimes of states in 150Nd were measured using the recoil distance method following Coulomb excitation of 150Nd by a 132 MeV 32S beam. The experiment was performed at the Yale Tandem accelerator, employing the SPEEDY gamma-ray detector array and the New Yale Plunger Device. Reduced transition probabilities in 150Nd are compared to the predictions of the critical point symmetry X(5) of the phase/shape transition that occurs for the N = 90 rare earth isotones. Very good agreement was observed between the parameter-free (apart from scale) X(5) predictions and the low-spin level scheme of 150Nd, revealing this as the best case thus far for the realization of the X(5) symmetry.

Methods are described for determining four of the principal constituents of phosphate rock with a single sample. Acid-insoluble material is determined gravimetrically, while phosphate iron and aluminum are determined colorimetrically. The phosphovanadomolybdate method is used for the phosphate determination, 1,10-phenantholine for iron, and alizarin for aluminum.Interference of iron in the alizarin method for aluminum is practically eliminated by making measurements at 370 millimicrons.The accuracy obtained using the methods described compares favorably with that of the commonly used gravimetric and volumetric methods and the colorimetric methods are considerably faster. THE methods in general use for the determination of the most important constituents of phosphate rock-namely, acid-insoluble, calcium phosphate, iron, and aluminum-are volumetric and gravimetric. They have been in use for many years, with minor changes, and although they give satisfactory results in the hands of a good analyst, they have several disadvantages. Three samples and two additional weighings are required for the four determinations. The stirring and filtration equipment needed for large scale volumetric phosphate determinations occupies a considerable amount of desk space. The determination of combined iron and aluminum usually by precipitation as phosphates after removal of calcium, is very slow' and requires a good deal of desk space for filtration. The aluminum result is calculated by subtracting the iron, determined volumetrically, from the combined iron and aluminum. The doubtful value of the indirect aluminum determination is reflected in the wide variations in results reported by different analysts on identical samples of phosphate rock.This paper presents methods for determining the abovementioned constituents of phosphate rock using only one sample, with a minimum of laboratory space and equipment. All the determinations are made by colorimetric methods, except for the gravimetric determination of acid-insolubles.

Excited states in 138Ce have been studied via the 12C(138Ce, 138Ce*) Coulomb excitation reaction at 480 MeV. Relative cross sections have been determined from the gamma-ray yields observed with Gammasphere. The E2 and M1 strength distributions between the lowest six 2+ states up to 2.7 MeV enables us to identify the 2(4)+ state in 138Ce as the dominant fragment of the one-phonon 2(1,ms)+ mixed-symmetry state. Mixing between this level and a nearby isoscalar state is observed and is more than 4 times larger than in the neighboring isotone 136Ba. This is direct evidence that the stability of mixed-symmetry states strongly depends on the underlying subshell structure.

The B(E2;0(+)-->2+) values for the first 2+ excited states of neutron-rich 132,134,136Te have been measured using Coulomb excitation of radioactive ion beams. The B(E2) values obtained for 132,134Te are in excellent agreement with expectations based on the systematics of heavy stable Te isotopes, while that for 136Te is unexpectedly small. These results are discussed in terms of proton-neutron configuration mixing and shell-model calculations using realistic effective interactions.

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