ХАРАКТЕРИСТИКА СОРТОВ АМАРАНТА СЕЛЕКЦИИ ВНИИССОК ПО УСТОЙЧИВОСТИ К ПОНИЖЕННОЙ ТЕМПЕРАТУРЕ И ДЕФИЦИТУ ВЛАГИ ПРИ ВЫРАЩИВАНИИ В МОСКОВСКОЙ ОБЛАСТИ И РЕСПУБЛИКЕ ЭКВАДОР

Analysis of morphological and physiological characters of amaranth varieties of VNIISSOK and Ecuador breeding grown under optimal conditions, as well as at low temperature and precipitation deficit showed a reduction in height, number of leaves and inflorescence length to different extents. It points to the different resistance of varieties to the unfavorable environmental factors.Анализ морфофизиологических показателей растений амаранта сортов селекции ВНИИССОК и Эквадора, выращенных в оптимальных условиях, а также при пониженной температуре и дефиците осадков, выявил снижение высоты, числа листьев и длины соцветий в неодинаковой степени, что указывает на различный уровень устойчивости сортов к действию неблагоприятных факторов среды. Наиболее полное представление об устойчивости сорта можно получить при многолетней оценке морфофизиологических показателей при выращивании растений в открытом грунте при меняющихся из года в год неблагоприятных факторах среды. Помимо этого, дополнительную информацию об устойчивости сортов амаранта дает сопоставление элементов продуктивности растений, выращенных в разных географических зонах (Россия, Эквадор). Важные морфофизиологические параметры растений (высота, количество листьев, длина соцветия) использовали для более полной характеристики устойчивости сортов к действию абиогенных стрессоров. Внутрисортовая и межсортовая специфичность растений амарантпо показателям «высота», «число листьев» и «длина соцветий» четко проявилась при их выращивании в России и Эквадоре. Пониженная температура (13,9°С) и дефицит влаги являются стрессовым фактором для амаранта, задерживающим рост и нарастание листьев и соцветий у всех исследованных сортов за исключением сортов Неженка и Кизлярец, устойчивых к действию стрессоров. Представленные в работе данные свидетельствуют, что ростовые реакции растений амаранта изученных сортов более чувствительны к действию пониженной температуры, чем к дефициту влаги

Isomer shift and magnetic moment of the long-lived 1/2+^{+} isomer in 3079^{79}_{30}Zn49_{49}: signature of shape coexistence near 78^{78}Ni

Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\mu$ ($^{79}$Zn) = $-$1.1866(10) $\mu_{\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\nu g_{9/2}^{-1}$ shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment $\mu$ ($^{79m}$Zn) = $-$1.0180(12) $\mu_{\rm{N}}$ supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the $N = 50$ shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state: $\delta \langle r^{2}_{c}\rangle^{79,79m}$ = +0.204(6) fm$^{2}$, providing first evidence of shape coexistence.Comment: 5 pages, 4 figures, 1 table, Accepeted by Phys. Rev. Lett. (2016

Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers

Collinear laser spectroscopy was performed on Zn (Z=30) isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N=33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N=50. Exactly one long-lived (>10 ms) isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ=1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N=43, while the progression towards 79Zn points to the stability of the Z=28 and N=50 shell gaps, supporting the magicity of 78Ni

Binding energies of ground and isomeric states in neutron-rich ruthenium isotopes: measurements at JYFLTRAP and comparison to theory

We report on precision mass measurements of $^{113,115,117}$Ru performed with the JYFLTRAP double Penning trap mass spectrometer at the Accelerator Laboratory of University of Jyv\"askyl\"a. The phase-imaging ion-cyclotron-resonance technique was used to resolve the ground and isomeric states in $^{113,115}$Ru and enabled for the first time a measurement of the isomer excitation energies, $E_x(^{113}$Ru$^{m})=100.5(8)$ keV and $E_x(^{115}$Ru$^{m})=129(5)$ keV. The ground state of $^{117}$Ru was measured using the time-of-flight ion-cyclotron-resonance technique. The new mass-excess value for $^{117}$Ru is around 36 keV lower and 7 times more precise than the previous literature value. With the more precise ground-state mass values, the evolution of the two-neutron separation energies is further constrained and a similar trend as predicted by the BSkG1 model is obtained up to the neutron number $N=71$.Comment: 12 pages, 9 figures, submitted to Physical Review

High-precision measurements of low-lying isomeric states in 120−124^{120-124}In with JYFLTRAP double Penning trap

Neutron-rich $^{120-124}$In isotopes have been studied utilizing the double Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. Using the phase-imaging ion-cyclotron-resonance technique, the isomeric states were resolved from ground states and their excitation energies measured with high precision in $^{121,123,124}$In. In $^{120,122}$In, the $1^+$ states were separated and their masses were measured while the energy difference between the unresolved $5^+$ and $8^-$ states, whose presence was confirmed by post-trap decay spectroscopy was determined to be $\leq15$ keV. In addition, the half-life of $^{122}$Cd, $T_{1/2} = 5.98(10)$ s, was extracted. Experimental results were compared with energy density functionals, density functional theory and shell-model calculations.Comment: 11 pages, 7 figure

Structural trends in atomic nuclei from laser spectroscopy of tin

Tin is the chemical element with the largest number of stable isotopes. Its complete proton shell, comparable with the closed electron shells in the chemically inert noble gases, is not a mere precursor to extended stability; since the protons carry the nuclear charge, their spatial arrangement also drives the nuclear electromagnetism. We report high-precision measurements of the electromagnetic moments and isomeric differences in charge radii between the lowest 1/2(+), 3/2(+), and 11/2(-) states in Sn117-131, obtained by collinear laser spectroscopy. Supported by state-of-the-art atomic-structure calculations, the data accurately show a considerable attenuation of the quadrupole moments in the closed-shell tin isotopes relative to those of cadmium, with two protons less. Linear and quadratic mass-dependent trends are observed. While microscopic density functional theory explains the global behaviour of the measured quantities, interpretation of the local patterns demands higher-fidelity modelling. Measurements of the hyperfine structure of chemical elements isotopes provide unique insight into the atomic nucleus in a nuclear model-independent way. The authors present collinear laser spectroscopy data obtained at the CERN ISOLDE and measure hyperfine splitting along a long chain of odd-mass tin isotopes.Peer reviewe

Nuclear charge radius of 26m^{26m}Al and its implication for Vud_{ud} in the quark-mixing matrix

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope $^{26m}$Al. The measured isotope shift to $^{27}$Al in the 3s^{2}3p\;^{2}\!P^\circ_{3/2} \rightarrow 3s^{2}4s\;^{2}\!S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of $^{26m}$Al, resulting in $R_c$=\qty{3.130\pm.015}{\femto\meter}. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed $\beta$ decay of $^{26m}$Al. Its corrected $\mathcal{F}t$ value, important for the estimation of $V_{ud}$ in the CKM matrix, is thus shifted by one standard deviation to \qty{3071.4\pm1.0}{\second}.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Let

Laser Spectroscopy of Neutron-Rich Tin Isotopes: A Discontinuity in Charge Radii across the N=82 Shell Closure

The change in mean-square nuclear charge radii δ⟨r2⟩ along the even-A tin isotopic chain 108−134Sn has been investigated by means of collinear laser spectroscopy at ISOLDE/CERN using the atomic transitions 5p2 1S0→5p6 s1P1 and 5p2 3P0→5p6s 3P1. With the determination of the charge radius of 134Sn and corrected values for some of the neutron-rich isotopes, the evolution of the charge radii across the N=82 shell closure is established. A clear kink at the doubly magic 132Sn is revealed, similar to what has been observed at N=82 in other isotopic chains with larger proton numbers, and at the N=126 shell closure in doubly magic 208Pb. While most standard nuclear density functional calculations struggle with a consistent explanation of these discontinuities, we demonstrate that a recently developed Fayans energy density functional provides a coherent description of the kinks at both doubly magic nuclei, 132Sn and 208Pb, without sacrificing the overall performance. A multiple correlation analysis leads to the conclusion that both kinks are related to pairing and surface effects

Changes in nuclear structure along the Mn isotopic chain studied via charge radii.

The hyperfine spectra of Mn-51,Mn-53-64 were measured in two experimental runs using collinear laser spectroscopy at ISOLDE, CERN. Laser spectroscopy was performed on the atomic 3d(5) 4s(2) S-6(5/2) -> 3d(5) 4s4p P-6(3/2) and ionic 3d(5) 4s S-5(2) -> 3d(5) 4p P-5(3) transitions, yielding two sets of isotope shifts. The mass and field shift factors for both transitions have been calculated in the multiconfiguration Dirac-Fock framework and were combined with a King plot analysis in order to obtain a consistent set of mean-square charge radii which, together with earlier work on neutron-deficient Mn, allow the study of nuclear structure changes from N = 25 across N = 28 up to N = 39. A clear development of deformation is observed towards N = 40, confirming the conclusions of the nuclear moments studies. From a Monte Carlo shell-model study of the shape in the Mn isotopic chain, it is suggested that the observed development of deformation is not only due to an increase in static prolate deformation but also due to shape fluctuations and triaxiality. The changes in mean-square charge radii are well reproduced using the Duflo-Zuker formula except in the case of large deformation

Changes in nuclear structure along the Mn isotopic chain studied via charge radii

The hyperfine spectra of Mn-51,Mn-53-64 were measured in two experimental runs using collinear laser spectroscopy at ISOLDE, CERN. Laser spectroscopy was performed on the atomic 3d(5) 4s(2) S-6(5/2)-> 3d(5) 4s4p P-6(3/2) and ionic 3d(5) 4s S-5(2)-> 3d(5) 4p P-5(3) transitions, yielding two sets of isotope shifts. The mass and field shift factors for both transitions have been calculated in the multiconfiguration Dirac-Fock framework and were combined with a King plot analysis in order to obtain a consistent set of mean-square charge radii which, together with earlier work on neutron-deficient Mn, allow the study of nuclear structure changes from N = 25 across N = 28 up to N = 39. A clear development of deformation is observed towards N = 40, confirming the conclusions of the nuclear moments studies. From a Monte Carlo shell-model study of the shape in the Mn isotopic chain, it is suggested that the observed development of deformation is not only due to an increase in static prolate deformation but also due to shape fluctuations and triaxiality. The changes in mean-square charge radii are well reproduced using the Duflo-Zuker formula except in the case of large deformation.Peer reviewe