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In this study, we develop a method for high precision Cd isotope analysis by double spike MC-ICP-MS. Two-step Cd purification using AG-MP-1M resin and TRU resin was used to separate Cd from samples with a recovery of more than 95% Cd and a blank less than 0.1 ng. A practical double spike design and optimization procedure is proposed and the effect of the double spike ratio in the double spike-sample mixture (p) on the measured δ114/110Cd is evaluated, which broadens the appropriate p range from 0.3–0.6 to 0.1–0.8. In addition, the observed shift/deviation of the measured δ114/110CdNIST 3108 value from zero-delta due to the change of experimental conditions is discussed on a theoretical basis and a correction approach is developed. Potential Mo and Zr based polyatomic ions have no significant effect on δ114/110Cd in typical geological samples, while isobaric ions such as Sn, Pd and In can seriously affect the accuracy of measurements even at low concentration. It is shown that the tolerances of isobaric interference can be improved to 0.1, 0.05 and 0.02 for Sn/Cd, Pd/Cd and In/Cd, respectively, after mass discrimination correction. The precision and accuracy of the proposed method were verified by analyzing mixtures of NIST 3108 and a secondary reference material BGEG-Cd of different composition. Long term monitoring of the measured NIST 3108 and BGEG-Cd showed repeatability for δ114/110Cd of 0.00 ± 0.04‰ and −1.00 ± 0.04‰ (2sd, n = 45), respectively. Finally, we measured Cd isotope compositions of several geological standard materials including soil sediments and manganese nodules, and the δ114/110Cd values of 0.01 ± 0.02‰ (GSD-5a), 0.04 ± 0.02‰ (GSD-7a), −0.06 ± 0.05‰ (GSD-10), −0.34 ± 0.06‰ (GSD-11), −0.10 ± 0.06‰ (GSD-12), 0.10 ± 0.04‰ (GSD-17), 0.05 ± 0.03‰ (GSD-21), and 0.10 ± 0.07‰ (GSD-23) were in good agreement with the reported values, and a δ114/110Cd value of −0.08 ± 0.04‰ (GSD-3a) was reported for the first time.

The drainage of rice soils increases Cd solubility and results in high Cd concentrations in rice grains. However, plant Cd uptake is limited by sorption to iron plaques, and Cd redistribution in the plant is regulated by the nodes. To better understand the interplay of Cd uptake and redistribution in rice under drained and flooded conditions, we determined stable Cd isotope ratios and the expression of genes coding transporters that can transport Cd into the plant cells in a pot experiment. In soil, both water management practices showed similar patterns of isotope variation: the soil solution was enriched in heavy isotopes, and the root Fe plaque was enriched in light isotopes. In rice, the leaves were heavier (Δ114/110Cdleaf-shoot = 0.17 to 0.96‰) and the nodes were moderately lighter (Δ114/110Cdnode-shoot = -0.26 to 0.00‰) relative to the shoots under flooded conditions, indicating preferential retention of light isotopes in nodes and export of heavy isotopes toward leaves. This is generally reversed under drained conditions (Δ114/110Cdleaf-shoot = -0.25 to -0.04‰, Δ114/110Cdnode-shoot = 0.10 to 0.19‰). The drained treatment resulted in significantly higher expression of OsHMA2 and OsLCT1 (phloem loading) but lower expression of OsHMA3 (vacuolar sequestration) in nodes and flag leaves relative to the flooded treatment. It appeared that OsHMA2 and OsLCT1 might preferentially transport isotopically heavier Cd, and the excess Cd was purposefully retranslocated via the phloem under drained conditions when the vacuoles could not retain more Cd. Cd in seeds was isotopically heavier than that in stems under both water management practices, indicating that heavy isotopes were preferentially transferred toward seeds via the phloem, leaving light isotopes retained in stems. These findings demonstrate that the Fe plaque preferentially adsorbs and occludes light Cd isotopes on the root surface, and distinct water management practices alter the gene expression of key transporters in the nodes, which corresponds to a change in isotope fractionation between shoots and nodes/leaves.

With new advancements in MC-ICP-MS technology, small Cd isotope fractionations in geological processes have attracted more interest in recent years. However, challenges remain in obtaining high-precision Cd isotope data for geological samples with low Cd concentrations and complex matrices. By an improved Cd purification and cleaning resin scheme for low-Cd samples using AGMP-1M resin with >90% Cd recovery, the ratios of trace elements Sn, Mo, Zr, etc. to Cd in the samples, which could potentially jeopardize the accuracy and precision of Cd isotope analysis under a high-sensitivity setup, were less than 0.001 after purification, and the total procedure blank is ≤0.1 ng. Hence, a sample containing 20–30 ng Cd can be employed for purification and subsequent isotope measurement. Cadmium isotope fractionation (expressed in δ114/110Cd relative to NIST 3108) during column separation and instrument mass bias was corrected for by a 111Cd–113Cd double spike. NIST 3108 was determined at a concentration of 5–25 ng mL−1 on a Neptune Plus (112Cd signal intensity: ∼640 V ppm−1) and 25–50 ng mL−1 on a Nu plasma III (112Cd signal intensity:∼280 V ppm−1) MC-ICP-MS equipped with an Aridus II/III desolvator for more than one year, with a total external analytical precision of 0.034‰ (2SD, n = 181). NIST SRM 2711a, NOD-P-1 and GSS-1 were measured at 5, 10, 20, 25 and 50 ng mL−1 levels to be 0.532 ± 0.038‰, 0.133 ± 0.038‰ and 0.098 ± 0.027‰, respectively, indicating that good accuracy and precision of Cd isotope analysis can be achieved with an injecting sample size as low as 5 ng Cd. Our method can be reliably applied to various geological reference materials (GRMs). The δ114/110Cd values of GRMs with relatively high and low Cd concentrations are consistent with previous studies: NOD-A-1 (0.124 ± 0.067‰), GSD-11 (−0.274 ± 0.037‰) and BCR-2 (−0.030 ± 0.063‰). SGR-1b (0.069 ± 0.049‰), GSH-1 (−0.337 ± 0.077‰) and others are reported for the first time in this paper. The δ114/110Cd in basalt and stream sediments is relatively homogeneous and overlaps with that of the bulk silicate earth (BSE). The δ114/110Cd in shale and soils varies greatly from −0.694 to 0.532‰. Human hair and other animal organs are enriched in light isotopes relative to BSE, whereas terrestrial plants are enriched in heavy isotopes.

Understanding oceanic cadmium (Cd) cycling is paramount due to its micronutrient‐like behavior in seawater, which has been inferred from its similarity to phosphate (PO4) cycling. Cadmium concentrations follow a nutrient‐like consumption‐regeneration cycle in the top of the water column and are mainly controlled by water mass mixing and circulation in the deep ocean. However, an additional scavenging mechanism through cadmium sulfide (CdS) precipitates, occurring within sinking biogenic particles in oxygen deficient zones (ODZ), has been proposed. In this study, we report Cd stable isotope and concentration data for seven vertical seawater profiles sampled during GEOTRACES cruise GA08 in the northern Cape and Angola Basins, which feature a significant ODZ along their eastern margins. Outside the ODZ, Cd cycling is similar to that previously reported for the South Atlantic. While water mass mixing largely controls deep ocean Cd isotope signatures, Cd isotope fractionation in surface waters can be modelled as an open system at steady‐state buffered by organic ligand complexation. In the ODZ, stronger Cd depletion relative to PO4 is associated with a shift in δ114Cd towards heavier values, which is indicative of CdS precipitation. Our interpretation is supported by experimental CdS precipitation data and a size‐resolved particle model involving bacterial sulfate reduction as a precursor of CdS. Our estimates of the CdS flux to the seafloor (107 to 109 mol yr‐1) indicate that CdS precipitation is a significant process of Cd removal and constitutes a non‐negligible Cd sink that needs to be better quantified by Cd isotope analyses of marine sediments.

The neutron capture cross-sectional reactions for 106,108,110,111,112,113,114,116Cd isotopes have been calculated with different level density models which are constant temperature Fermi gas (CTFG) model, back-shifted Fermi gas model, generalized superfluid model and Hartree–Fock–Bogoliubov model by using TALYS 1.9 and EMPIRE 3.2 codes for incident neutron energies up to 250 keV. The obtained results have been analyzed with each level density model parameters existing in Reference Input Parameter Library (RIPL-3) and available experimental data. As an outcome, to obtain more precise and coherent calculations with the experimental values, level density model and its parameters have been determined. Also, hadronic interactions of low-energy neutrons have been investigated for a situation by using GEANT4. © 2019, Indian Association for the Cultivation of Science.

Cd isotopes (107Cd and 109Cd) are generated from the silver target body during the bombardment of [18O]water in the routine production of 2-[18F]fluoro-2-deoxy- d -glucose ([18F]FDG) for PET (Positron Emission Tomography) diagnosis. Cadmium isotopes contribute significantly to the total activity of generated impurities and, due to being potentially radiotoxic to living organisms, they should be effectively reduced from FDG to prevent accidental injection of even small concentrations into patients. Purification of the final [18F]FDG can be based on a set of columns, fulfilling various functions in the cleaning process. To assess cadmium impurities and the efficiency of the purification process, a low background gamma spectrometry system with high resolution has been applied. Even activity of 3.5 kBq and 290 kBq has been measured on QMA (Sep-Pak Light Accell Plus QMA) columns for 109Cd and 107Cd isotopes, respectively. 107Cd activity in the five column set was higher than that of 109Cd. The rate of 18F production process was about 1 GBq/min, while that of 107Cd and 109Cd radionuclides was about 4.2 kBq/min and 50 Bq/min respectively. The same purification efficiency of both isotopes has been obtained at each step of the process. The production rate of 107Cd and 109Cd radionuclides was insignificant compared to the 18F production rate. Therefore [18F]FDG final product for use in injections before PET diagnostics was efficiently purified from cadmium radionuclide impurities.

The potential-energy surfaces (PESs) for ground states of even-even $^{102--112}\mathrm{Cd}$ isotopes are obtained by using the three-dimensional relativistic Hartree-Bogoliubov model with the density-dependent meson exchange interaction. The quadrupole deformation parameters are extracted from the PES calculations and employed in the beyond mean-field projected shell model to study the yrast and excited states of these isotopes. Besides, the $E2$ transition probabilities and $g$ factors are obtained and compared with the experimental data. The present calculations support the experimental finding that yrast ${8}^{+}$ states of light Cd isotopes are of ${(\ensuremath{\pi}{g}_{9/2})}^{2}$ character whereas the yrast ${10}^{+}$ states of medium-mass Cd isotopes are found to possess ${(\ensuremath{\nu}{h}_{11/2})}^{2}$ character.

International audience; Cadmium (Cd) isotopes are known to fractionate during complexation with various environmentally relevant surfaces and ligands. Our results, which were obtained using (i) batch experiments at different Cd concentrations, ionic strengths, and pH values, (ii) modeling, and (iii) infrared and X-ray absorption spectroscopies, highlight the preferential enrichment of light Cd isotopes bound to humic acid (HA), leaving the heavier Cd pool preferentially in the solution (Δ114/110CdHA-Cd(aq) of -0.15 ± 0.01‰). At high ionic strengths, Cd isotope fractionation mainly depends on its complexation with carboxylic sites. Outer-sphere complexation occurs at equilibrium together with inner-sphere complexation as well as with the change of the first Cd coordination and its hydration complexes in solution. At low ionic strengths, non-specific Cd binding induced by electrostatic attractions plays a dominant role and promotes Cd isotope fractionation during complexation. This significant outcome elucidates the mechanisms involved in HA-Cd interactions. The results can be used during (i) fingerprinting the available Cd in soil solution after its complexation with solid or soluble natural organic matter and (ii) evaluate the contribution of Cd complexation with organic ligands and phytoplankton-derived debris vs. Cd assimilation by phytoplankton in seawater.

Nucleosynthetic isotope variations are well documented for refractory elements in meteorites and the Earth, while moderately volatile elements generally display homogeneous compositions. Cadmium is a moderately volatile element with eight stable isotopes generated by a variety of nucleosynthetic processes. To address the extent of the nucleosynthetic variability in moderately volatile elements, new high precision Cd isotope data are presented for bulk samples of six carbonaceous and one enstatite chondrite. In addition, we report the first Cd isotope results of sequential acid leachates for the CM2 chondrite Jbilet Winselwan. Our new Cd data displays nucleosynthetic homogeneity for bulk chondrites and acid leachates within analytical uncertainties, in agreement with results for other moderately volatile elements. This implies that Cd isotopes were efficiently homogenised prior to incorporation into planetary bodies. We propose that Cd never significantly condensed into dust in stellar environments, or alternatively that such Cd-bearing dust was efficiently destroyed and recycled in the interstellar medium. Our leachate data provides evidence for further homogenisation during thermal processing in the protoplanetary disk including parent body processing. The data shows that Cd in carbonaceous chondrites mainly resides in the more easily dissolved phases, most likely sulphides that were affected by aqueous alteration. Less than 1% of the total Cd was recovered in the final leach fractions that employed HF and mainly dissolve silicates and refractory oxides. Cadmium is susceptible to thermal neutron-capture effects due to the large neutron capture cross-section of 113Cd (∼20,000 barns). We report variations of up to −0.6 ± 0.3 for ε113Cd (internally normalised to 116Cd/111Cd) in bulk chondrites, which renders Cd a potential thermal neutron-capture monitor. Most neutron dosimeters, such as Pt, Os and Hf, are sensitive to neutron capture in the epithermal energy range and have applications mainly limited to lunar samples or iron and stony-iron meteorites. The additional use of Cd, susceptible to neutron capture in the thermal energy range, therefore provides a new tool to determine the exposure histories of stony meteorites in more detail. Our study demonstrates that thermal neutron-capture effects in carbonaceous and enstatite chondrites can produce resolvable effects and require attention when assessing nucleosynthetic isotope variations., Geochimica et Cosmochimica Acta, 274, ISSN:0016-7037, ISSN:1872-9533

This paper presents a new method for the separation of Sn and Cd from geological matrices followed by high-precision isotope analyses that include low abundance isotopes (

Remobilization of zinc (Zn) from shoot to grain contributes significantly to Zn grain concentrations and thereby to food quality. On the other hand, strong accumulation of cadmium (Cd) in grain is detrimental for food quality. Zinc concentrations and isotope ratios were measured in wheat shoots (Triticum aestivum) at different growth stages to elucidate Zn pathways and processes in the shoot during grain filling. Zinc mass significantly decreased while heavy Zn isotopes accumulated in straw during grain filling (Δ66 Znfull maturity-flowering = 0.21-0.31‰). Three quarters of the Zn mass in the shoot moved to the grains, which were enriched in light Zn isotopes relative to the straw (Δ66 Zngrain-straw -0.21 to -0.31‰). Light Zn isotopes accumulated in phloem sinks while heavy isotopes were retained in phloem sources likely because of apoplastic retention and compartmentalization. Unlike for Zn, an accumulation of heavy Cd isotopes in grains has previously been shown. The opposing isotope fractionation of Zn and Cd might be caused by distinct affinities of Zn and Cd to oxygen, nitrogen, and sulfur ligands. Thus, combined Zn and Cd isotope analysis provides a novel tool to study biochemical processes that separate these elements in plants.

Excitation functions were calculated for the α-particle induced reactions 115In(α,x)117mSn, 114Cd(α,n)117mSn, 116Cd(α,3n)117mSn and natCd(α,x)117mSn to analyse the production of the medically important 117mSn (T½ = 13.6 d). For calculations three nuclear model codes (i.e. TALYS, EMPIRE and ALICE-IPPE) were used and the results were compared with the available experimental data. For the most important reaction, 116Cd(α,3n)117mSn, evaluated data are presented. The yield and radionuclidic purity of 117mSn from each reaction are discussed.

The projected shell model framework has been employed to carry out a systematic study on the deformation systematics of E ( 2 1 + ) and E ( 4 1 + ) / E ( 2 1 + ) values, BCS subshell occupation numbers, yrast spectra, backbending phenomena and electromagnetic quantities in 114–128Cd isotopes. Present calculations reproduce the observed systematics of the E ( 2 1 + ) , R 42 and B ( E 2 ; 2 + → 0 + ) values for 114–128Cd isotopic mass chain and give the evidence that deformation increases as one moves from 114Cd to 118Cd, thereafter it decreases up to 126Cd. This in turn confirms 118Cd to be the most deformed nucleus in this set of isotopic mass chain. The emergence of backbending, decrease in B ( E 2 ) values and change in g-factors in all these isotopes are intimately related to the crossing of g-band by 2-qp bands.

9 pags., 7 figs., Quadrupole moments and charge radii in cadmium isotopes are studied from a microscopic perspective. The results obtained from self-consistent deformed Hartree-Fock+BCS calculations with Skyrme forces are compared with isomer and isotope shifts measured from high-resolution laser spectroscopy experiments. The microscopic calculations reproduce fairly well the main features observed in those isotopes that include the linear increase with the neutron number of the quadrupole moments of the 11/2¿ isomers, as well as the parabolic behavior of the mean-square charge radii difference between isomers and ground states., This work was supported by Ministerio de Ciencia, Innovación y Universidades MCIU/AEI/FEDER,UE (Spain) under Contract No. PGC2018-093636-B-I00.

Consumption of rice (Oryza sativa) grain is a major pathway by which humans are exposed to Cd, especially in non-smoking Asian populations. Although the stable isotope signatures of Cd offer a potential tool for tracing its sources, little is known about the isotopic fractionation of Cd across the entire soil-rice-human continuum. Cadmium isotope ratios were determined in field soils, rice grain, and human urine collected from two Cd-contaminated regions in southern China. Additionally, Cd isotopic fractionation in rice plants was investigated using two transgenic plants differing in Cd uptake and accumulation. Analysis of isotope ratios revealed a preferential enrichment of the heavy Cd isotopes from soil to rice grain (δ114/110Cdgrain-soil = +0.40‰) and from grain to urine (δ114/110Cdurine-grain = +0.40‰) in both regions. The first increase was mainly caused by partitioning between the soil solid phase and the soil solution, with heavier Cd preferentially enriching in the soil solution. Within the rice plant, we identified multiple processes that alter the isotope ratio, but the net effect throughout the plant was comparatively small. Cd fractionation in humans is presumably due to the preferential enrichment of heavier Cd isotopes by metal transporters DMT1 and ZIP8 (responsible for the absorption of Cd into body from the foods). These findings provide important insights into the Cd isotopic fractionation through the soil-rice-human continuum and are helpful for tracing the sources of Cd.

Cadmium (Cd) calcite coprecipitation experiments were conducted to constrain the possible Cd isotope fractionation mechanism under different conditions. The changes in Cd/Ca molar ratio, HCO3− concentration, addition of Mg2+, Na2EDTA, or ionic strength (INaNO3) did not affect the composition of the precipitation but resulted in substantial change in mineral morphology. Cd exhibited an apparent isotope fractionation in the process of coprecipitation with calcite, and the fractional coefficient αCaCO3-Cd(aq) was less than one, indicating that the solution is preferentially enriched in heavy isotopes. The Cd mainly existed in the form of Cd(H2O)62+ in the solution before the reaction and was dominated by Cd(NO3)2, CdNO3+, Cd(EDTA)2− at the end of the experiments. The different isotopic ratios of Cd between the liquid phase and the solid phase can be explained by changes in Cd speciation which have different bond lengths of Cd O. Expect for the experiments with Na2EDTA and high ionic strength, the measured isotope ratios under different conditions plotted around the theoretical Rayleigh fractionation curve. This demonstrates that Cd isotopes almost reach equilibrium with Cd-calcite coprecipitation under the different experiment conditions and the Cd isotope fractionation mechanism is closely related to the thermodynamic isotope fractionation. In the experiment with Na2EDTA and high ionic strength, the formation of Cd(EDTA)2− and ion occlusion at surface sites inhibit Cd2+ entering the calcite and the isotopes of the solid and liquid phases do not reach equilibrium. As the result, obtained experiment data shift from the Rayleigh fractionation curve indicating the Cd isotope fractionation mechanism is closely related to the kinetic isotope effect. In general, the study results indicate that the Cd/Ca molar ratio, ionic strength, HCO3−, Na2EDTA, and Mg2+ concentrations of the solution can cause Cd isotope fractionation in different degrees during Cd-calcite coprecipitation. Cd isotope ratios might potentially provide important information on Cd mobilization and transportation in groundwater environment.

The gamma-activation technique was used to measure the absolute yields of photonuclear reactions on the cadmium isotopes 106,108Cd. The results obtained in this way were compared with the results of the calculations based on the statistical model. For reactions on the isotope 108Cd, agreement between these theoretical and experimental results is good, but the experimental ratio of the yields of photoproton and photoneutron reactions on the isotope 106Cd differs substantially from its theoretical counterpart. The results of our present study are discussed from the point of view of the production of bypassed nuclei in the p-process of nucleosynthesis.

Physics letters / B 754, 288 - 293 (2016). doi:10.1016/j.physletb.2016.01.039, Published by North-Holland Publ., Amsterdam

Heavy metals pollutants are global concern due to their toxicities and persistence in the environment. Cd isotope signatures in soils and sediments change during weathering, and it remains unclear if Cd isotopes can effectively trace Cd sources in a riverine system. In this study, we investigate Cd concentration and its isotope compositions, as well as other heavy metals of sediments and related potential Cd sources in a riverine system. The results showed that the two river sediments evaluated were moderately polluted by Zn, Cr, and Cd, while the source samples (soil, sludge, waste, and raw materials) were seriously polluted by heavy metals derived from anthropogenic activities. According to comprehensive ecological risks, the two sediments have a moderate to low potential risk and more than half of all anthropogenic activities in the study area were at considerable or moderate potential risk. We determined that Cd pollution in river sediments was primarily derived from sewage treatment and outlets based on river flow direction and the isotope geochemical behaviors of the Cd isotope in nature conditions. This study further confirmed that analyzing Cd isotopes could be a powerful tool for tracing the source and destination of environmental Cd for multiple sources with similar Cd concentrations.

The structure of even-even $^{108-116}$Cd isotopes is investigated based on the self-consistent mean-field approach. By mapping the quadrupole-$(\beta,\gamma)$ deformation energy surface, obtained from the constrained self-consistent mean-field calculations with a choice of the Skyrme force and pairing property, onto the Hamiltonian of the interacting boson model with configuration mixing, the strength parameters of the Hamiltonian are determined. The low-lying excitation spectra and electric quadrupole transition rates for the considered Cd nuclei are computed by the resultant Hamiltonian, and are compared in detail with the experimental data. Our semi-microscopic prediction identifies several intruder states as suggested empirically, and overall, provides a reasonable qualitative description of the experimental energy levels and transition rates., Comment: 9 pages, 4 figures, 4 tables

The irradiations of Ag to Sn targets by bremsstrahlung generated with 23-MeV electron beams are performed at the MT-25 microtron. Gamma spectra of the induced activities have been measured and the yields of all detected radionuclides and isomers are carefully measured and analyzed. A regular dependence of yields versus changed reaction threshold is confirmed. Many isomers are detected and the suppression of the production probability is observed with growing product spin. Special peculiarities for the isomer-to-ground state ratios were deduced for the 106mAg, 108mAg, 113mIn, 115mIn, and 123mSn isomers. The production of such nuclides as 108mAg, 115mIn, 117gIn, and 113mCd is of interest for applications, especially when economic methods are available.

This study reports a systematic approach of quantum chemical calculations (density functional theory) of cadmium isotope reduced partition function ratios to understand the fractionation properties of Cd species in hydrothermal fluids, including cadmium hydrate, chloride, hydroxide, nitrate, hydrosulfide complexes. The optimized structures and the calculated vibrational frequencies of the selected Cd complexes by B3LYP method are consistent with the experimental data. The reduced partition function ratios 103ln (β114–110) of the Cd complexes were calculated with varying temperatures from 0 °C to 400 °C or 500 °C, which are from 0.680‰ to 2.098‰ at 50 °C. The isotope fractionation between different Cd species seems to be small, and there exists a trend of heavy Cd isotope enrichment as cadmium hydroxides > cadmium nitrates > cadmium hydrates > cadmium chlorides > cadmium hydrosulfide, according to the calculated reduced partition function ratios 103ln (β114–110) by this study. This suggests that Cd hydroxide complexes and hydrosulfide complexes may produce larger fractionation than others, which even reaches + 1.641‰ between Cd(OH)Cl and CdHS+ at 25 °C. As the major Cd-bearing species in hydrothermal conditions, CdOH(H2O)5+ and CdCl(H2O)5+, the fractionation factor α is found to be + 0.120‰ at 150 °C. These theoretical calculations provide insight into Cd isotope behavior in solution conditions, especially in hydrothermal fluids.

We present the results of precision mass measurements of neutron-rich cadmium isotopes. These nuclei approach the $N=82$ closed neutron shell and are important to nuclear structure as they lie near doubly-magic $^{132}$Sn on the chart of nuclides. Of particular note is the clear identification of the ground state mass in $^{127}$Cd along with the isomeric state. We show that the ground state identified in a previous mass measurement which dominates the mass value in the Atomic Mass Evaluation is an isomeric state. In addition to $^{127/m}$Cd, we present other cadmium masses measured ($^{125/m}$Cd and $^{126}$Cd) in a recent TITAN experiment at TRIUMF. Finally, we compare our measurements to new \emph{ab initio} shell-model calculations and comment on the state of the field in the $N=82$ region.

Large-scale shell-model calculations for the even-even cadmium isotopes Cd-98-Cd-108 have been performed with the ANTOINE code in the pi(2p(1/2); 1g(9/2)).(2d(5/2); 3s(1/2); 2d(3/2); 1g(7/2); 1h(11/2)) model space without further truncation. Known experimental energy levels and B(E2) values could be well reproduced. Taking these calculations as a starting ground we analyze the deformation parameters predicted for the Cd isotopes as a function of neutron number N and spin J using the methods of model independent invariants introduced by Kumar [Phys. Rev. Lett. 28, 249 (1972)] and Cline [Annu. Rev. Nucl. Part. Sci. 36, 683 (1986)].

The experimental nuclear spectroscopic data for known nuclides of mass number 129 (Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm) have been evaluated and presented together with adopted properties for levels and γ rays. This evaluation represents a revision of the previous one 18 years ago by Y. Tendow (1996Te01). Extensive new data have become available for many nuclides in the intervening years, although, no data are available for excited states in {sup 129}Pm and {sup 129}Sm, and for {sup 129}Ag and {sup 129}Cd, only limited information is available for the g.s. and isomers. The decay schemes of {sup 129}Ag, {sup 129}Pm and {sup 129}Sm are unknown, and those for {sup 129}Cd, {sup 129}In, {sup 129}Ce, {sup 129}Pr and {sup 129}Nd are incomplete. Many γ rays and extended level schemes have been reported for the ground state and isomer decays of {sup 129}Ba to {sup 129}Cs, yet the adopted set of intensities in this evaluation originate from a brief paper in an annual laboratory report. There remain several unplaced gamma rays, coupled with ambiguity about division of intensities amongst the two activities of {sup 129}Ba with nearly the same half-lives. Isomerism ismore » expected in {sup 129}Pr, but there is no confirmed identification. Low-lying level structure in {sup 129}Nd, including identification of a possible third long-lived isomer in this nuclide, remains uncertain. The spin-parity assignments of (5/2+) for the ground state and (7/2−) for an isomer at 107.6 keV in {sup 129}Ce are assigned based on strong support from systematics and band configurations, yet this result is in contradiction with the quadrupole interaction hyperfine structure measurement which favors 9/2− over 7/2− for the isomer, consequently 7/2+ for the ground state. Direct measurements of spins of ground state and isomer of {sup 129}Ce are needed to settle this issue. Confirmed spins and parities of the ground state and isomer of {sup 129}La are also lacking. Assignments in this work are mainly based on systematics of h{sub 11/2} decoupled structures. A direct measurement of ground state spin of {sup 129}La will also be desirable. Recommended data presented in this work supersede those in previous NDS evaluations of A=129 nuclides published by 1996Te01, 1983Ha46 and 1972Ho55.« less

The yields of photonucleon reactions having various multiplicities and occurring on a natural mixture of cadmium isotopes were measured. Bremsstrahlung whose spectrum had an endpoint energy of 55 MeV was used as a gamma-ray source. The reaction yields were determined with the aid of the induced-activity method. The yields of photonuclear reactions for several channels of decay of excited states of cadmium isotopes in the energy region extending up to 55MeV were obtained for the first time. A comparison of the results obtained experimentallywith the results of theoretical calculations reveals that, in the case of heavy cadmium isotopes, it is possible to obtain a reasonably good description of experimental data. In the case of the light isotope 106Cd, however, the results of the theoretical calculations are at odds with experimental data, and this is likely to be due to special features of the shell structure of the isotope 106Cd, which lies near the beta-stability boundary.

Tracing the sources of heavy metals in water environment is key important for our understanding of their pollution behavior. In this present study, Cd concentrations and Cd isotopic compositions in sediments were determined to effectively identify possible Cd sources. Results showed that elevated concentrations and high enrichment factor for Cd were found in all sediments, suggesting anthropogenic Cd origin. Cd isotopic compositions in sediments yielded relative variations ranged from -0.35‰ to 0.07‰ in term of δ(114/110)Cd (the mean: -0.08‰). Large fractionated Cd was found in sediments collected from a smelter and an E-waste town. Cd isotopic compositions and Cd concentrations measured in sediments allowed the identification of three main origins (dust from metal refining (δ(114/110)Cd0), slag of metal refining (δ(114/110)Cd0), and those δ(114/110)Cd = 0, such as background and mining activity). According to the actual precision obtained, Cd isotopes could be a potential tool for tracing metal pollution sources in water environment.

Investigations of cadmium isotope variations in the oceans may provide new insights into the factors that control the marine distribution and cycling of this element. Here we present the results of Cd isotope and concentration analyses for 22 seawater samples from the Atlantic, Southern, Pacific, and Arctic Oceans. The results reveal, for the first time, large and well resolved Cd isotope fractionations in the marine environment. The majority of the seawater samples display an inverse relationship between dissolved Cd contents and isotope compositions, which range from ε114/110Cd ≈ + 3 ± 0.5 for Cd-rich waters (0.8-1.0 nmol/kg) to ε114/110Cd ≈ 38 ± 6 for surface water with a Cd concentration of only 0.003 nmol/kg (all ε114/110Cd data are reported relative to the JMC Cd Münster standard). This suggests that the Cd isotope variations reflect kinetic isotope effects that are generated during closed system uptake of dissolved seawater Cd by phytoplankton. A few samples do not follow this trend, as they exhibit extremely low Cd contents (< 0.008 nmol/kg) and nearly un-fractionated Cd isotope compositions. Such complexities, which are not revealed by concentration data alone, require that the Cd distribution at the respective sites was affected by additional processes, such as water mass mixing, atmospheric inputs of Cd and/or adsorption. Uniform isotope compositions of ε114/110Cd = + 3.3 ± 0.5 (1 S.D.) were determined for seawater from ≥ 900 m depth, despite of Cd concentrations that display the expected increase along the global deep-water pathway from the Atlantic (∼ 0.3 nmol/kg) to the Pacific Ocean (∼ 0.9 nmol/kg). This indicates that the biomass, which is remineralized in the deeper ocean, is also characterized by a very constant Cd isotope composition. This observation is in accord with the interpretation that the Cd distribution in surface waters is primarily governed by Rayleigh fractionation during near-quantitative uptake of dissolved seawater Cd. © 2007 Elsevier B.V. All rights reserved.

Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ114/110Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ114/110Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits.

Cadmium isotopes were fractionated by the liquid–liquid extraction technique with a crown ether, dicyclohexano-18-crown-6. The isotopic ratios of m Cd/ 111 Cd (m: 110, 112, 113, 114, and 116) were measured precisely by the multi-collector inductively coupled plasma spectrometry (MC-ICP-MS). When the isotope enrichment factors were calculated, the odd atomic mass isotopes ( 111 Cd and 113 Cd) showed excesses of enrichment comparing to the even atomic mass isotopes ( 110 Cd, 112 Cd, 114 Cd and 116 Cd). This odd–even staggering property originates from the nuclear field shift effect. The contribution of the nuclear field shift effect to the observed isotope enrichment factor was estimated to be 5 to 30%.

Recent experimental results obtained using β decay and isomer spectroscopy indicate an unusual behaviour of the energies of the first excited 2 + states in neutron-rich Cd isotopes approaching the N = 82 shell closure. To explain the unexpected trend, changes of the nuclear structure far-off stability have been suggested, namely a quenching of the N = 82 shell gap already in 130Cd, only two proton holes away from doubly magic 132Sn. We study the behaviour of the 2 + energies in the Cd isotopes from N = 50 to N = 82 , i.e. across the entire span of a major neutron shell using modern beyond mean field techniques and the Gogny force. We demonstrate that the observed low 2 + excitation energy in 128Cd close to the N = 82 shell closure is a consequence of the doubly magic character of this nucleus for oblate deformation favoring thereby prolate configurations rather than spherical ones.

The 1994 evaluation on mass A = 106 has been revised, taking into account all data available before May 2007. Detailed experimental information is presented from the neutron rich nucleus {sup 106}Y to the neutron deficient {sup 106}Te nucleus. All conversion coefficients have been calculated with BRICC.

The hyperfine quadrupole interactions of 111In/111Cd probes in the polycrystalline isostructural Zr4Al3 and Hf4Al3 compounds were studied. Strong preference of 111In solute for the Zr3Al2 and Hf3Al2 phases occurring as contaminant fractions in the measured samples was observed.

Gravimetric synthetic mixtures of seven enriched, purified cadmium isotope materials were used to determine the correction factors for mass fractionation (MC-TIMS) and mass discrimination (MC-ICP-MS). The isotope abundance ratios determined for various natural cadmium materials represents the isotope composition for natural cadmium materials. Correction of the isotope abundance ratios observed yielded isotope abundances of 106 Cd 0.012450(8), 108 Cd 0.008884(4), 110 Cd 0.124846(16), 111 Cd 0.127955(14), 112 Cd 0.241110(38), 113 Cd 0.122254(22), 114 Cd 0.287439(60) and 116 Cd 0.075183(32). The newly determined atomic weight of natural cadmium based on SI-traceable evaluation of the isotope abundance ratios is 112.41384(18). The cadmium material designated in the paper as Cd-2211 can be used as an isotope reference material with a δ ( 114 Cd/ 110 Cd)-value of 0‰. The results obtained show that the uncertainties for the isotope abundances and the atomic weight given as IUPAC values for cadmium are overestimated.

A new technique has been developed for the accurate and precise determination of the stable Cd isotope composition of seawater. The method utilizes a 110 Cd– 111 Cd double spike, and it involves separation of Cd from seawater by column chromatography and isotopic analyses by multiple collector inductively coupled plasma mass spectrometry. As a by-product, it also generates precise Cd concentration data. Repeated analyses of three pure Cd reference materials and three seawater samples yielded reproducibilities of about ±1.0 to ±1.6 e 114/110 Cd (2 SD), based on measurements that each consumed about ∼8 ng of natural Cd ( e 114/110 Cd is the deviation of the 114 Cd/ 110 Cd isotope ratio of a sample from the standard in parts per 10,000). This demonstrates that the new double spike technique is superior to published methods of Cd isotope analyses, with regard to the acquisition of precise data for samples of limited size. Additional experiments showed that as little as 1–5 ng of seawater Cd could be analyzed with a precision of about ±2 to ±6 e 114/110 Cd (2 SD). The accuracy of the seawater isotope data was ascertained by experiments in which a Cd-free seawater matrix was doped with small quantities of isotopically well-characterized Cd. Repeated mass scans that were carried out on purified Cd fractions of several samples furthermore demonstrated the absence of significant spectral interferences. The isotope data that were acquired for the three seawater samples reveal, for the first time, small but resolvable Cd isotope fractionations in the marine environment. Cadmium-rich intermediate water from the North Pacific was found to have an isotope composition of e 114/110 Cd = 3.2 ± 1.0. In contrast, Cd-depleted seawater from the upper water column of the Atlantic and Arctic Oceans displayed isotope compositions of e 114/110 Cd = 6.4 ± 1.1 and 6.6 ± 1.6, respectively. These observations are in accord with the interpretation that the isotope effects are due to the biological fractionation that occurs during the uptake of dissolved seawater Cd by phytoplankton.

International audience; A new experiment devoted to searches for double electron capture in Cd-106 decay is being performed at the Modane underground laboratory (4800 mwe) with the 32-detector TGV-2 spectrometer. The limit T (1/2)(2 nu EC/EC) > 2.0x10(20) yr at a 90%confidence level (C.L.) was obtained from a preliminary analysis of data obtained over 2250 h of measurements with about 23.2 g sample enriched in the isotope Cd-106 to 99.57%. The limits T (1/2)(KL, 2741 keV) > 0.9 x 10(20) yr and T (1/2)(KK, 2718 keV) a parts per thousand << 1.4 x 10(20) yr at a 90% C.L. on the neutrinoless decay of Cd-106 were obtained from measurements performed with the Obelix low-background spectrometer from high-purity germanium (HPGe spectrometer) for a sample of mass about 23.2 g enriched in the isotope Cd-106.

This issue of Hyperfine Interactions consists of 21 articles describing scientific work related to the research at the on-line isotope separator facility IGISOL at the University of Jyvaskyla, Finland. Ten contributions containing a significant amount of original results, earlier unpublished, have been presented as a Topical Collection in the European Physical Journal (EPJA 48 issue No 4, 2012). In the early 1980s, the Ion Guide Isotope Separator On-Line (IGISOL) concept was realized at the 20 MeV proton cyclotron of the Physics Department at the University of Jyvaskyla (JYFL). For the first time, the technique allowed the production of high quality ISOL beams from nuclear reaction products with millisecond delay times without chemical restrictions. By providing access to short-lived isotopes of refractory elements it opened up new regions in the nuclear chart for nuclear decayand ground-state spectroscopy. During the 1980s, the main research activity at IGISOL was decay spectroscopy, and in particular, of fission products produced in proton-induced fission of natural uranium. Approximately 40 new isotopes and isomers were discovered and studied employing beta-, gamma-, and conversion electron spectroscopy. These experiments covered a broad range of neutron-rich nuclei from yttrium (Z = 39) to cadmium (Z = 48) and revealed how their structure was developing between highly deformed zirconium through triaxial ruthenium isotopes to weakly deformed vibrational cadmium isotopes. The original IGISOL facility was shut down in October 1991 and was reinstalled as IGISOL-2 at the science campus housing the laboratory for the K = 130 MeV heavy ion cyclotron. A new window of opportunity for extending research to neutrondeficient nuclei far from stability was opened and was going to have a strong impact

The perturbed angular correlation technique was applied to study the lattice location of the 111In/111Cd and 181Hf/181Ta probe atoms in hafnium and zirconium aluminides. Compounds of different stoichiometries and crystallographic structures were the subject of investigation. According to the expectation, in all investigated compounds 181Hf/181Ta probes occupy the Hf(Zr) crystallographic sites. The 111In/111Cd probes are placed at the sites of all constituent metals — aluminum, hafnium and zirconium, depending on the crystallographic structure of compound, concentration of the constituent metals and temperature of the sample.

The Gamow–Teller β decays of the neutron-deficient indium isotopes 104–107 In have been investigated by using total absorption γ -ray spectrometry on mass-separated sources. The experimental Gamow–Teller strength, deduced as a function of the excitation energy in the daughter nuclei 104–107 Cd, is compared to shell-model predictions.

The production of very neutron-deficient isotopes near 100Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for 99Cd, 100In, 101Sn and 102In via 58Ni+58Ni fusion reactions followed by cluster emission, and via 58Ni+50Cr fusion reactions accompanied by evaporation of protons, neutrons or α particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near 100Sn. The data are discussed in comparison with results obtained from statistical-model calculations.

The 1991 evaluation of A = 107 has been revised. Experimental information is presented for various A = 107 nuclides, from the neutron-rich 107 Nb to the neutron-deficient 107 Te. All data available before June 1999 have been considered.

The γ‐spectrometry method for determination of the relative change ΔλEC/λEC in the partial probability λEC for the 114mIn decay branch by the electron capture (EC), when the nucleus is in different chemical environments, was developed. The method is based on an experimental determination of the relative change ΔIγ/Iγ in the intensity of the γ‐radiation which is emitted by the excited daughter 114Cd nuclei after EC. The 114mIn decay by EC in indium metal, In2O3 and InAs was compared. The largest ΔIγ/Iγ=(2.5±0.8)·10−4 has been found for InAs relatively to In2O3. The chemical changes in the electron density on the indium nucleus corresponding to the measured ΔIγ/Iγ values have been determined.

The method described to determine the neutron fluence is based on the plot of the isotopic variation of Cd and Gd subjected to neutron irradiation in a research reactor. The isotopic ratios are measured by thermal ionization mass spectrometry. The results indicate that the fluence values obtained, using the variation in the ratios114Cd/113Cd,156Gd/155Gd and158Gd/157Gd show standard deviations varying from 0.3 to 6.6%. These values agree with the extrapolated values calculated using the short time Au activation method. The method appears to be useful for determining paleo neutron flux in natural samples and irradiated fuels.

The basic regularities for enrichment of the 116Cd isotope in the form of cadmium dimethyl in a single gas centrifuge and a square cascade of gas centrifuges have been studied by means of numerical simulation techniques. In these computing experiments it has been found the influence of a loss of the process gas due to its partial decomposition to enrichment of the desired isotope.

The β decay of the neutron-deficient isotope 103 In was investigated by using total absorption γ-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the β-decay strength in striking disagreement with high-resolution γ-ray data. The result is discussed in comparison with shell-model predictions.

母材の異なる標準容積線源から放出されるγ線およびX線を用いて, 母材の線減弱係数に対するn型ゲルマニウム検出器の低エネルギー光電ピーク効率の関係を求めた。その結果, 88keVより低エネルギー側で母材に依存しない滑らかな曲線を得た。また, 種々の物質に対する10keVから2MeVまでの光子の質量減弱係数を一つの近似関数で表した。これらの結果を用いることにより, 線減弱係数が0.04-20cm-1の範囲に入る光電ピーク効率が計算でき, それらのγ線およびX線を放出する核種を10%程度の誤差で定量可能となった。

Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac–Hartree–Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor–crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg 2 Cl 2 ), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from 119 Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium.

The study of Fe, Zn and Cd stable isotopes (δ(56)Fe, δ(66)Zn and δ(114)Cd) in seawater is a new field, which promises to elucidate the marine cycling of these bioactive trace metals. However, the analytical challenges posed by the low concentration of these metals in seawater has meant that previous studies have typically required large sample volumes, highly limiting data collection in the oceans. Here, we present the first simultaneous method for the determination of these three isotope systems in seawater, using Nobias PA-1 chelating resin to extract metals from seawater, purification by anion exchange chromatography, and analysis by double spike MC-ICPMS. This method is designed for use on only a single litre of seawater and has blanks of 0.3, 0.06 and

The electromagnetic features of the 11/2− isomers in the odd-mass Cd isotopes are shown to exhibit an an anomaly near N = 70. We report shell-model calculations of these isotopes aimed at describing these properties. We find a sudden phase change in the hexadecapole component of the wave functions precisely at N = 70, which gives rise to different linear relations between the Q and μ values before and after N = 70, as needed to reproduce the experimental data. The particle-hole transformation properties associated with a strong subshell closure at N = 70 followed by fairly close-lying neutron orbitals from N = 70 − 82 is suggested as a possible explanation for this phase change.