[en] This patent describes a continuous chromatographic process for the simultaneous separation of each of the isotopes of zirconium in a sample containing a mixture of zirconium isotopes to produce substantially pure fractions of each of the separated isotopes. It comprises: loading a substantially vertical chromatographic separation column having an effective column height sufficient to resolve each the zirconium isotope into a distinct product fraction having a purity greater than 90% with a cation exchange resin having a strong affinity for zirconium cations; the resin having a solid to liquid distribution coefficient in excess of about 100 in acid solutions of less than about 0.3 normal; preparing an aqueous feed solution of ionic zirconium from the sample having a pH of between about 3 and 4 and a solubility limit of about 90 g/l; and preparing an eluant capable of displacing zirconium ions from the exchange resin, wherein the eluant is an aqueous solution of a strong mineral acid having a normality greater than one

No abstract available

[en] A method of separating zirconium isotopes by converting the zirconium to its iodide salt prior to separation by usual isotope methods is disclosed. After separation the desired isotopes are converted from the salt to the metal by the van Arkel-de Boer iodide process

[en] This patent describes a process for reducing the thermal neutron cross-section of zirconium by increasing the concentration of the low cross-section isotopes and decreasing the concentration of the high cross- section isotopes which comprises subjecting an essentially anhydrous alcoholic solution of an ionic zirconium compound with a higher than desired distribution of high cross-section isotopes to continuous steady state chromatography utilizing a cation exchange resin with pentavalent phosphorus derived active groups as the stationary phase, collecting at least two product fractions, one enriched in zirconium 90 and the other enriched in zirconium 94, and combining them to yield a zirconium with a lower cross-section than the starting zirconium

No abstract available

[en] New developments in the description of finite nuclei are discussed

[en] We present a detailed analysis of spectra and other observables for the entire chain of Zr isotopes, from neutron number 52 to 70, in the framework of the interacting boson model with configuration mixing. The results suggest a remarkable interplay of multiple quantum phase transitions (QPTs). One type of QPT involves an abrupt crossing of normal and intruder configurations, superimposed on a second type of QPT involving gradual shape-changes within each configuration.

[en] The relative abundances of the six stable or nearly-stable isotopes of zirconium were measured for three S stars, R Cyg, V Cnc, and R Gem. The method of analysis utilized the isotopic splitting of the head of the ¹Pi - ¹EPSILON (0,1) head of ZrO, with the abundances being determined by comparing the observed stellar profile of intensity vs. wavelength with synthetic spectra calculated by the Minnaert interpolation scheme for a single-slab LTE stellar atmosphere. The presence of the long-lived unstable isotope ⁹³Zr supports the hypothesis that nucleosynthesis is taking place in the S stars, while the absence of the r-process isotope ⁹⁶Zr supports the hypothesis that the s process is the mechanism responsible for this nucleosynthesis. The observed isotopic abundances suggest a value for the integrated neutron flux of tau = 0.5 +- 0.1 mb^-1, corresponding to an average of about 50 neutrons captured per seed nucleus

[en] This patent describes a continuous chromatographic process for the simultaneous separation of each of the isotopes of zirconium in a sample containing a mixture of zirconium isotopes to produce substantially pure fractions of each of the separated isotopes. It comprises loading a substantially vertical chromatographic separation column having an effective column height sufficient to resolve each the zirconium isotope into a distinct product fraction having a purity greater than 90% with a cation exchange resin including pentavalent phosphorus-derived active groups having a strong affinity for zirconium cations and complexes thereof; preparing an aqueous feed solution of ionic zirconium from the sample having a pH of between about 3 and 4 from a solubility limit of about 90 g/l; preparing an eluant capable of displacing zirconium ions from the exchange resin, wherein the eluant is an aqueous solution of a strong mineral acid having a normality greater than one; feeding the aqueous zirconium feed solution to the top of the located chromatographic separation column so that the feed solution begins to travel down the column

No abstract available