The level structure of 114Cd from (n, γ) and (d,p) studies

Gamma rays and conversion electrons have been measured following thermal neutron capture in ¹¹³Cd using the crystal spectrometers GAMS and the β-spectrometer BILL at the High Flux Reactor of the ILL at Grenoble. Primary γ-rays following thermal and average resonance neutron capture at E_n = 2 keV and 24 keV were recorded at the High Flux Beam Reactor at the Brookhaven National Laboratory. The ¹¹³Cd(d, p)¹¹⁴Cd reaction was studied with the Q3D spectrograph at the Munich tandem accelerator. Combining all these experimental results an almost complete level scheme of ¹¹⁴Cd was constructed up to 3.3 MeV including 48 excited levels with spin and parity information. The level scheme is discussed in terms of particle-hole excitations across the Z = 50 closed shell coupled to collective states, as well as in an interacting boson configuration mixing scheme.     

Determination of the isotope shift of115m Cd by a Zeeman scanning method

We have used an optical pumping-Zeeman scanning technique in order to determine the isotope shift in the 3,261 Å resonance line of 43-day, spin-11/2^115m Cd. A sample of ≈5×10¹² atoms was aligned in the¹ S ₀ diamagnetic ground state by optically pumping the sample with one selected Zeeman-scanned component of the³ P ₁?3,261 Å resonance line from a¹¹⁴Cd lamp. The alignment was detected through the modulation of the pumping beam at the nuclear resonance frequency. Thus by Zeeman scanning theF = 9/2 component of the³ P ₁ level and using previously determinedA- andB-values, we findδ5v(114–115m (9/2))= ?4,234(48) MHz and¹¹⁴Cd-^115mCd isotope shift = 87(48) MHz. We calculate a staggering parameterγ(^115mCd)=0.73(26), and a change in mean-square nuclear charge radiusδ〈r ²〉^114,115m =0.035(18)fm².     

Multipole mixing ratios of transitions in175Lu populated from the decay of175Hf

Electron capture decay of¹⁷⁵Hf(70 d) provides a possibility for unambiguous determination of the sign and magnitude of multipole mixing ratios for 89 keV and 114 keV transitions in¹⁷⁵Lu. This is because both gamma rays are in coincidence with the 230 keV transition which is of a pureE2 character. The results of theγ —γ directional correlation measurements, in terms ofE2/M1 mixing ratiosδ, areδ ₈₉ = 0.11±0.07 andδ ₁₁₄ = 0.465±0.005. In addition the directional correlation measurements of the 89γ- 343γ and 319γ-114γ cascades yieldδ ₃₄₃ = 0.08±0.07 andδ ₃₁₉ = ?0.152±0.015.Radioactivity ¹⁷⁵Hf from¹⁷⁴Hf(n, γ); measuredγ —γ(θ) deducedδ(E2/M1); Ge(Li) detectors.     

Decay Mechanism of 290,292114* Superheavy Nuclei Formed in 48Ca-Induced Reactions

We calculate the neutron-evaporation residue cross sections σ _3n , σ _4n , and σ _5n in the hot-fusion reactions ⁴⁸Ca+^242,244Pu →^290,292114 ^? over a wide range of compound-nucleus excitation energies ( $E_{\text{CN}}^{*}$ = 34–53 MeV). We work with the dynamical cluster-decay model (DCM), with a single parameter, the neck-length parameter ΔR. To calculate neutron-evaporation cross sections, we choose the superheavy proton magic Z = 126 and neutron magic N = 184. Among the 3n, 4n, and 5n production cross sections for ^{290, 292}114^?, only the 3n decay cross sections of ²⁹²114^? correspond to spherical fragmentation. The 4n and 5n cross sections of ²⁹²114^? and 3n, 4n, and 5n cross sections of ²⁹⁰114^? could only be fitted after the inclusion of quadrupole deformations β _2i within the optimum orientation approach. Changes in the angular momentum and N/Z ratio do not significantly influence the fragmentation paths of ^{290, 292}114^? superheavy nuclei. Larger barrier modification is required for the lower angular momentum states and lighter neutron clusters. The contribution of the fusion–fission component is also computed for the compound nucleus ²⁹²114^? in the energy range $E_{\text{CN}}^{*}$ = 27–47 MeV.     

Structural and magnetic properties of Mn3−xCdxTeO6 (x=0, 1, 1.5 and 2)

Mn₃TeO₆ exhibits a corundum-related A₃TeO₆ structure and a complex magnetic structure involving two magnetic orbits for the Mn atoms [Ivanov et al., 2011 [3]]. Mn_3−xCd_xTeO₆ (x=0, 1, 1.5, and 2) ceramics were synthesized by solid state reaction and investigated using X-ray powder diffraction, electron microscopy, and calorimetric and magnetic measurements. Cd²⁺ replaces Mn²⁺ cations without greatly affecting the structure of the compound. The Mn and Cd cations were found to be randomly distributed over the A-site. Magnetization measurements indicated that the samples order antiferromagnetically at low temperature with a transition temperature that decreases with increasing Cd doping. The nuclear and magnetic structure of one specially prepared ¹¹⁴Cd containing sample: Mn_1.5¹¹⁴Cd_1.5TeO₆, was studied using neutron powder diffraction over the temperature range 2-295 K. Mn_1.5¹¹⁴Cd_1.5TeO₆ was found to order in an incommensurate helical magnetic structure, very similar to that of Mn₃TeO₆ [Ivanov et al., 2011 [3]]. However, with a lower transition temperature and the extension of the ordered structure confined to order 240(10) Å.     

Search for resonances in 12C(9Be, α)17O

Excitation functions at 7° (lab) have been measured from E_c.m. = 5.1 to 11.4 MeV in approximately 114 keV steps for 15 groups of final states in ¹⁷O populated by the ¹²C(⁹Be, α) reaction. Statistical tests have been used to locate possible non-statistical structure in the excitation functions. Possible anomalies were found near E_c.m. = 6.3, 7.5, 8.9 and 9.7 MeV. Angular distributions were measured at E_c.m. = 9.20, 9.71 and 10.23 MeV for the three lowest excited states in ¹⁷O. The data have been compared with Hauser-Feshbach calculations in addition to the following reaction mechanisms: compound plus a single resonance, compound plus interfering resonances and compound plus direct reactions.     

Proton-neutron multiplet states in 114In

The γ-ray spectrum of the ¹¹⁴Cd(p, nγ)¹¹⁴In reaction was measured with Ge(Li) and Ge(HP) spectrometers at 4.8, 5.3, and 7.0 MeV bombarding proton energies. The energies (E_γ) and relative intensities (I_γ) of more than 170 γ-ray transitions in ¹¹⁴In have been determined. The electron spectrum of the reaction was measured with a combined magnetic plus Si(Li) spectrometer. Internal conversion coefficients of 38 transitions in ¹¹⁴In were determined for the first time. The level scheme of ¹¹⁴In, γ-ray branching ratios, multipolarity of transitions, level parity and spin values have been deduced. The energies of several ¹¹⁴In proton-neutron multiplets were calculated on the basis of the parabolic rule derived from the cluster-vibration model. The comparison of experimental and theoretical results provided classification of about 18 multiplet states in ¹¹⁴In. The experimental level scheme has also been compared with former theoretical calculations.     

Level structures in the 114 In nucleus

High-spin states in ¹¹⁴In were populated using the reaction ¹¹⁰Pd(⁷Li, 3n)¹¹⁴In at a beam energy of 26MeV. The level scheme of ¹¹⁴In consisting of six bands is established up to excitation energy ～ 5MeV and spin ～ 17 ? with the addition of 58 new transitions and their configurations are discussed. The intense positive-parity dipole cascade may be interpreted as shears band based on $ \pi$ [(g _9/2)^-1] ? $ \nu$ [(g _7/2/d _5/2)(h _11/2)²] configuration. The $ \Delta$ I = 2 bands based on proton excitation have been observed in ¹¹⁴In for the first time.     

Electromagnetic transition strengths and nuclear moments in123Xe

The level structure of¹²³Xe has been studied with the¹¹⁴Cd (¹²C, 3n) and^?Cd (¹³C, 4n) reactions using in-beamγ-ray spectroscopy. The yrast cascade on the low lying odd parity states originating from theh _11/2 neutron orbital has been investigated yielding lifetimesτ of 18(3) ps, 2.2 (4) ns and 17(2) ns for the 15/2^?, 11/2^? and 9/2^? states, respectively. Theg-factor of thet _1/2=5.2 μs isomer has been measured to beg=?0.256(2). From the time differential observation of the electric quadrupole interaction in a¹¹⁴Cd single crystal the spin of this isomer has been determined to be 7/2 and from the coupling constante ² Qq/h=116(2) MHz the quadrupole moment was deduced. The results are discussed in the framework of the triaxial rotor plus particle model.     

On photonuclear reaction mechanisms at intermediate energies

The¹²C(γ,2N) reactions have been studied using tagged photons ofE _γ = 114–600 MeV at the Mainz microtron (MAMI). The cross sections of the¹²C(γ,pn) reaction and the shape of¹²C(γ,pp) spectra compare well to model predictions over a wide range of photon energies and missing energies, suggesting that the dominant mechanisms of photonuclear reactions are understood.     

The 114In level scheme studied by the (n, γ) reaction

The level scheme of the nucleus ¹¹⁴In has been studied using capture of thermal neutrons. The experimental information is taken from γ singles spectra and γ-γ coincidence spectra and from delayed coincidence measurements. Levels up to 1.4 MeV excitation energy are proposed. Several short lifetimes of excited states in ¹¹⁴In and ¹¹⁶In could be measured. The binding energy of the last neutron in ¹¹⁴In, B_n = 7273.9 ± 1.2 keV, determined in this work is in strong disagreement with previously accepted values. Additional experimental information on the ¹¹⁶In level scheme is given. Six states of the ($\text{π(}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^{\mathrm{?1}}\text{, ν}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$) multiplet (3^? to 8^?) in ¹¹⁴In. The expected close similarity between many low-lying states in ¹¹⁴In and ¹¹⁶In could be confirmed. In particular, it was found that the anomalous high isomeric cross-section ratio of the second isomeric state results from very selective reorientation transitions within the negative-parity multiplet. The coupling constant of the quadrupole part of the residual neutron-proton interaction obtained from a theoretical calculation of the ¹¹⁴In level scheme is similar in size to that of ¹¹⁶In, thus giving credit to the explanation given in our previous ¹¹⁶In work. The splitting of multiplets in doubly odd In nuclei gives additional information for an interpretation of the so-called $\text{g}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^{\mathrm{?}}\text{h}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}$ anomaly in stripping studies near A = 110. Transition probability ratios B(M1)/B(E2) and E1 hindrance factors are discussed for both ¹¹⁴In and ¹¹⁶In. No sign of states exhibiting stable deformation similar to those in odd-A In nuclei has been found up to now in the doubly odd In nuclei studied. There is some evidence that these doubly odd In nuclei behave more like Cd than like single closed shell Sn nuclei.     

Physical, structural, and luminescence studies of Nd3+ doped MgO-ZnO borate glass

A series of borate glass of the system xNd₂O₃-5MgO-20ZnO-(75 ? x)B₂O₃, where x = 0.5, 1.0,1.5, 2.0, and 2.5 was successfully fabricated using melt quench method. The properties of the glass were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), absorption and luminescence spectra. The upconversion properties of Nd³⁺ doped borate glass were observed by using 574 nm excitation wavelength corresponding to ⁴ I _15/2 → ² H _114/2 transition. The emission bands centered at 460, 500 and 620 nm which corresponding to the Nd³⁺ transitions, ⁴ F _7/2 → ⁴ I _15/2, ² H _11/2 → ⁴ I _15/2, and ⁴ F _9/2 → ⁴ I _15/2 respectively were observed at room temperature. The presence of Nd³⁺ in borate based glass could intensify the upconversion luminescence spectra as it can potentially be used as host materials for upconversion lasers.     

Optical and x-ray diffraction investigations of the symmetry of distorted phases of the (NH4)2KGaF6 crystal

Powders and single-crystal plates of different sections of an (NH₄)₂KGaF₆ crystal are investigated using polarized light microscopy and x-ray diffraction over a wide temperature range, including the phase transition temperatures. It is established that the sequence of symmetry changes in the crystal under investigation is as follows: O _h ⁵ ?Fm3m (Z = 4) ? C _4h ⁵ ?I114/m (Z = 2) ? C _2h ⁵ ?P112₁/n (Z = 2).     

Isomerism,total decay energies,and absolute γ-ray intensities of the heavy Pd and Ag isotopes

The decays of^{113, 114, 115g, 115m, 116}Pd have been studied with an emphasis on the determinations of total decay energies and absoluteγ-ray intensities. The experiments also provided improved data on these quantities for the decays of^{114, 115g, 115m, 116m}Ag. A search for isomeric transitions using a high resolution electron detector resulted in the identification of isomericE3 transitions in¹¹⁵Pd and^{113, 115, 116, 117}Ag. The isomeric branching was determined in all cases. TheQ _β-values of^113–116Pd and^113–116Ag have been measured using aβγ-coincidence method.     

Fine-structure energy levels and autoionizing width calculations of magnesium-like Ni XVII

We have calculated highly excited fine-structure energy levels and their autoionizing width of 3pns ³ P ₁ (n = 11–26), 3pns ¹ P ₁ (n = 10–22), 3pnd ³ D ₁ (n = 11–26), 3pnd ³ P ₁ (n = 10–21), 3pnd ¹ P ₁(n = 10–21), 3dnp ³ D ₁ (n = 7–30), 3dnp ³ P ₁ (n = 7–28), 3dnp ¹ P ₁ (n = 7–28), 3dnf ³ D ₁ (n = 7, 9–27), 3dnf ³ P ₁ (n = 7, 9–27), and 3dnf ¹ P ₁ (n = 7, 9–27) for magnesium-like Ni XVII. The calculations are based upon the relativistic Breit-Pauli R-matrix approximation combining with the QB method of Quigley-Berrington (L. Quigley, K. A. Berrington, Pelan J. Comput. Phys. Commun. 114, 225 (1998)). We have reported the many unpublished energy values and autoionizing width of the J = 1 odd states of magnesium-like Ni XVII.     

Particle × phonon multiplets in 65 147 Tb82

High-spin states of¹¹⁵Sb were studied by inbeamγ-ray spectroscopy using the⁸⁹Y (²⁹Si, 2pn) fusionevaporation reaction at a beam energy of 108 MeV. The experiments includedγ-γ coincidence and directional correlation of oriented nuclei (DCO) ratio measurements using six BGO Compton suppressed Ge detectors. An intruderΔJ=2 rotational band has been identified for the first time and it is interpreted as the h_11/2 proton coupled to a two particle-two hole (2p ? 2h) deformed state of the¹¹⁴Sn core. A ΔJ=1 rotational band based on the 2p ? 1h, π{g ₇ ^2/2 ?g ₉ ^2/?1 }, configuration has been extended to the 29/2⁺ state at an excitation energy of 5241 keV.     

Infrared rotation-vibration spectra of ethane: The perpendicular band, ν7, of C2H6

The study of the gas-phase infrared spectrum of C₂H₆ in the region of the perpendicular CH-stretching band, ν₇, near 3000 cm^?1 is extended for the ΔK = + 1 subbands as far as K = 20. The spectral resolution of ～0.030 cm^?1 is increased to ～0.015 cm^?1 by deconvolution. The earlier investigation of this band for KΔK = +9 to ?5, is repeated with greater accuracy, providing more reliable ground-state constants (cm^?1): B₀ = 0.663089 ± 24, D₀^J = (0.108 ± 4) × 10^?5, D₀^JK = (0.50 ± 7) × 10^?5. The molecular constants (cm^?1) for the ν₇ fundamental are B₇ = 0.66310 ± 3, A₇ = 2.682, ν₀ = 2985.39, ζ₇ = 0.128. A discussion of resonance effects in this band, in particular x-y-Coriolis and Fermi resonance, is given.     

A new island of α-emission: α-decay energies and widths of neutron deficient tellurium,iodine and xenon isotopes

Using on-line mass separation, eight α-emitters (given with their α-decay energies in keV) in the trans-tin region were investigated: ¹⁰⁸Te, 3300(30); ¹⁰⁹Te, 3080(15); ¹¹⁰I, 3424(15); ¹¹¹I, 3150(30); ¹¹²I, 2866(50); ¹¹²Xe, 3185(30); ¹¹³Xe, 2990(30); ¹¹⁴Cs (or ¹¹⁴Ba), 3226(30). Systematics of $\text{Q}$_α values and reduced α-widths for this new island of α-emission are discussed.     

Search for cluster decay of114Ba

A search for the¹²C decay of¹¹⁴Ba produced in the⁵⁸Ni(⁵⁸Ni,2n) reaction was performed by using polycarbonate track detectors. Assuming the total half-life of¹¹⁴Ba to be 0.1 s, the lower limit T _c ≥10³ s for the partial¹²C-decay half-life was established.     

Alpha decay studies of tellurium,iodine, xenon and cesium isotopes

Very neutron-deficient isotopes in the trans-tin region were produced by reactions of 290 MeV ⁵⁸Ni ions on ⁵⁸Ni targets, and studied by on-line mass separation at GSI. Twelve α-emitters — ^107–110Te, ^110–113I, ^111–113Xe, ¹¹⁴Cs — were identified. Systematics of Q_α values and reduced α-widths for this new island of α-emission are discussed.