Levels in <Superscript>127</Superscript>La fed by the <Superscript>127</Superscript>Ce beta-decay

The low-lying levels in ¹²⁷La have been studied through the -decay of ¹²⁷Ce ( T_1/2 = 29s) produced by bombarding a ^natMo target with a 185-MeV ³⁵Cl beam. Reaction products were on-line mass-separated, and -ray singles and - coincidence measurements were performed. Conversion electrons were also measured and multipolarities of transitions have been derived. The half-life of the 210.9-keV level was determined to be (1.9±0.3)ns by the - delayed coincidence technique. The level scheme obtained has been compared with calculations based on the Nilsson model.     

Gamma-ray spectroscopy in 110Sn and 111Sn

Excited states in ¹¹⁰Sn and ¹¹¹Sn nuclei have been investigated using in-beam -ray spectroscopic methods. An ¹⁶O beam with an energy of 60-80MeV was used to bombard a ⁹⁸Mo target. On the basis of the relative excitation functions, -ray angular distributions, - and -time distributions, -ray multiplicity and total energy data, the level schemes of ¹¹⁰Sn and ¹¹¹Sn have been studied and extended up to E_exc 11.5MeV, I = 24, and E_exc 11.1MeV and I = (51/2), respectively. An extension of the intruder, g.s. and negative-parity bands, as well as 5 new band-like structures are proposed in ¹¹⁰Sn. The nature of newly introduced collective band 8 as well as 10⁺ states fed in the decay of the collective band is discussed. In the ¹¹¹Sn nucleus an intruder band based on the 23/2^- state has been reinvestigated and the extension of the g.s. band and second negative-parity band is given. Evidence for neutron-core coupling in ¹¹¹Sn is found. The structure and systematics of excited states in light Sn isotopes is discussed.     

Investigation of Rust Formed on Steel Surfaces and Related Oxyhydroxides

In order to indentity the corrosion products formed on steel surfaces from ⁵⁷Fe Mössbauer spectroscopy, detailed Mössbauer parameters have been determined for various kinds of iron-oxyhydroxides: -FeOOH, -FeOOH, -FeOOH and -FeOOH. ⁵⁷Fe Mössbauer measurements of the iron oxyhydroxides indicate the following results. Fe occupies a single site in -FeOOH, but below the Néel temperature as at e.g., 300 K the Mössbauer spectrum is always broad, showing a distribution of the strength of the magnetic exchange interactions. Its shape depends on the grain-size and synthetic methods of the specimen. Fe occupies 3 sites in -FeOOH. High-purity reagents of -FeOOH always contain small amounts of -FeOOH and their Néel temperatures depend on the synthetic methods of the specimen. Mössbauer spectroscopy of the synthetic -FeOOH shows very broad distribution of the hyperfine magnetic fields.     

Precision measurement of the half-life and the decay branches of 62Ga

In an experiment performed at the Accelerator Laboratory of the University of Jyväskylä, the -decay half-life of ⁶²Ga has been studied with high precision using the IGISOL technique. A half-life of T_1/2 = 116.09(17) ms was measured. Using - coincidences, the intensity of the 954 keV transition and an upper limit of the -decay feeding of the 0⁺₂ state have been extracted. The present experimental results are compared to previous measurements and their impact on our understanding of the weak interaction is discussed.     

The βdecay of 147Cs to 147Ba

The ^--decay of ¹⁴⁷Cs to ¹⁴⁷Ba has been studied by means of - and X-ray spectroscopy. A new level scheme of ¹⁴⁷Ba is significantly modified and extended in comparison to the one previously reported. The Advanced Time-Delayed (t) method has been applied to measure half-lives of the 46.2 and 85.4 keV levels in ¹⁴⁷Ba yielding T_1/2 of 510(80) ps and 370(100) ps, respectively. The lifetime results combined with the deduced internal conversion coefficients allowed to assign M1 multipolarity to three transitions. The B(M1) values obtained for the 39.2, 46.2 and 85.4 keV transitions range from 0.017 to 0.043 W.u. and represent typical B(M1) strength in the Ba-Er region. Model calculations using a shell correction approach with the axially deformed Woods-Saxon potential predict for ¹⁴⁷Ba an octupole deformed ground state with ₃ = 0.11.     

EC and α decays of 235Am

EC and decays of ²³⁵Am have been studied using a gas-jet coupled on-line isotope separator. Excited states in ²³⁵Pu have been established for the first time by means of -ray spectroscopy following the EC decay of ²³⁵Am. The deduced log ft value suggests that the ground state of ²³⁵Am should have the 5/2^-[523] configuration. The - coincidence result has revealed that the 5/2^-[523] state in ²³¹Np populated by the favored transition of ²³⁵Am is located at < 15 keV, which allows us to precisely determine the Q value of ²³⁵Am.     

Total absorption spectroscopy of the β-delayed proton emitter 117Ba

The very neutron-deficient ¹¹⁷Ba nuclei were produced in ⁵⁸Ni-induced reactions on a ⁶³Cu target and selected for spectroscopic studies by using BaF⁺ molecules formed in the ion source of the GSI on-line mass separator. The -decay of ¹¹⁷Ba was investigated by means of the total absorption -ray spectrometer and a telescope for -delayed particle detection. In the analysis combining the -delayed -ray and proton data the energy window available for -delayed proton emission, the branching ratios for proton transitions to the ¹¹⁶Xe levels and the -feeding of the -ray and proton-emitting ¹¹⁷Cs states were determined. The -strength function for ¹¹⁷Ba derived from the measured -feeding distribution revealed the existence of a broad resonance structure at ¹¹⁷Cs excitation energy of about 4-5 MeV. The results of the -delayed proton studies and -strength measurements are confronted with theoretical predictions.     

Interactions between dislocations and γ/γ' interfaces in superalloys

In situ transmission electron microscopy observations of the dislocation motion at vicinity of the /' interfaces in a Ni-base superalloy have been performed. They allow to identify the elemental mechanisms, under stress and at different temperatures, of the deformation propagation across the interfaces. It is shown that some of the mechanisms already analyzed in the literature occur. Moreover, new processes are revealed such as the formation of small dislocation pile-ups on the /' interfaces. Such a configuration, which increases the local stress, favors the overcoming of the interface.These observations together with new considerations on stresses are taken into account for proposing a new equilibrium equation for a dislocation abutting on a /' interface. This equation involves all the stress components acting on a dislocation: the applied stress, the misfit stress, the friction stress, the stress concentration due to the dislocation pile-up and the image stress.     

Lifetimes of proton unstable states in 113I measured by the particle-X-ray coincidence technique

The -delayed proton decay of ¹¹³Xe was investigated by means of a total absorption -ray spectrometer and a telescope for particle detection. The energy window available for the -delayed proton decay of ¹¹³Xe and the relative branching ratios for proton transitions to the ¹¹²Te states were remeasured. The lifetimes of proton unstable ¹¹³I states populated in the electron capture decay of ¹¹³Xe were determined by means of the particle-X-ray coincidence technique. The results of the lifetime measurements are compared with statistical-model calculations.     

Beta-decay studies of neutron-rich Sc- Cr nuclei

The neutron-rich nuclei ₂₁^{57, 58}Sc, ₂₂^58-60Ti, ₂₃^60-63V, ₂₄^62-66Cr have been produced at Ganil via interactions of a 61.8A MeV ⁷⁶Ge beam with a ⁵⁸Ni target. Beta-decay studies have been performed using combined - and -ray spectroscopy. Half-lives have been determined and -decay schemes are proposed for ⁵⁸Ti, ⁶¹V and ⁶²Cr. From these studies, new hints for the existence of -decaying isomers in ⁶⁰V and in ⁶²Mn are provided. These results are compared to shell model calculations. The role of the f_7/2- f_5/2 proton-neutron interaction is examined through its influence on the lifetime values.     

Updated Analysis of Gallium Chelate and Vanadium Chelate Solutions with 4‐(2‐Pyridylazo)Resorcinol and Xylenol Orange

The characteristic factors of the gallium and vanadium chelates with the ligands 4(2pyridylazo)resorcinol (PAR) and xylenol orange (XO) have been determined with the aid of the principle of correction, which makes it possible to eliminate the influence of the surplus ligand in the solution of its chelate with methane (which makes calculation easier) and thereby provides a more acceptable method in comparison with others. The real molar coefficients of extinction of the chelates Ga and V with PAR and XO have been determined and a detailed calculation of the stoichiometric ratios of chelates has been made. The results have shown that the chelates formed have the following structure: Ga(PAR), Ga(XO), V(PAR)₂, and V(XO).     

Beta-decay of 71Co and 73Co

A decay spectroscopy study of the neutron-rich cobalt isotopes has been performed using fragmentation of a ⁸⁶Kr³⁶⁺ beam and the new LISE2000 spectrometer at GANIL. For ⁷¹Co and ⁷³Co, the -delayed radiation has been observed for the first time, and the half-lives were found to be 79(5) ms and 41(4) ms, respectively. Features of the decay are discussed qualitatively in terms of nuclear models.     

Collective structures of the <Superscript>131</Superscript>Cs nucleus

The collective structures of ¹³¹Cs have been investigated by in-beam -ray spectroscopic techniques following the ¹²⁴Sn (^11B , 4n) reaction at a beam energy E_lab = 57MeV. The previously established rotational bands, built on g_7/2, d_5/2 and the unique-parity h_11/2 orbitals, have been extended and evolve into new bands involving rotationally aligned (h_11/2)² and (h_11/2)² quasiparticles. In addition, a new multiquasiparticle band based on the g_7/2 g_7/2 h_11/2 configuration has also been observed. Theoretical interpretations for the assigned configurations are discussed in the framework of Total Routhian Surface (TRS) and Tilted Axis Cranking (TAC) model calculations. TAC model calculations predict a decrease in the B(M1) values with increasing rotational frequency for the g_7/2/d_5/2 (h_11/2)² and h_11/2 (h_11/2)² bands, thus indicating a magnetic rotation character for these bands.     

Space Videophotometric System for Recording Optical Radiations in the Earth Atmosphere

This paper describes the VFS-3M videophotometric system designed for automatic remote recording of images and parameters of optical radiations following lightning discharges from aboard the Russian segment of the International space station. The characteristics of the system and the possibilities of recording such types of radiation as Red Sprites and Blue Jets are given.     

Synthesis of peptidomimetics using a polymer-bound Boc-linker

Boc-resin-bound -hydroxy--amino-aldehydes are accessible starting from N-terminally bound amino acidesters by using Dondoni's C₁-homologationreaction sequence. The conversion of these synthons totwo different peptide mimetics – 2-hydroxy-1,3-ethyl-diamines and -hydroxy--amino-vinyl sulfones – hasbeen investigated. The successful transfer of thecomplex -amino acid homologation reactionsequence into solid-phase chemistry demonstrates thepotentials of the Boc-resin for synthesis of peptidomimetics.     

PAC Measurements on New Ferromagnetic Compound Pd2TiSn

Magnetic hyperfine field (mhf) acting on ¹⁸¹Ta at the Ti site has been investigated in the alloy Pd₂TiSn by Perturbed Angular Correlation (PAC) measurements using the (133–482) keV – cascade in ¹⁸¹Ta following the ^– decay of ¹⁸¹Hf. The magnetic hyperfine field was measured as a function of temperature in the range of 45–1000K. The magnetization measurements were carried out with a vibrating sample magnetometer. The interpretation of the experimental results is based on the assumption that the probe nuclei occupy both the regular Ti sites as well as the Ti atom sites randomly distributed on the Pd sublattice.     

Decay studies of <Superscript>210-214</Superscript>Fr using α- γ-coincidences

The -decay fine structure of ^210-214Fr has been studied by --coincidence measurements. The nuclei were produced using the ¹²C on ²⁰⁹Bi reaction. Evaporation residues recoiling out of the target were separated in-flight by the velocity filter SHIP and stopped in a position-sensitive 16-strip PIPS-detector in order to study their subsequent decays. In the present work new and improved results for ^210-214Fr, produced by -decay of the primary reaction products ^214-218Ac, were extracted. The results are discussed and compared to previously published data.     

The maximum entropy principle as a consequence of the principle of Laplace

The maximum entropy principle states that the probability distribution which best represents our information is the one which maximizes the entropy with the given evidence as constraints. We prove that this principle is implied from the Laplace principle of equiprobabilities applied to the setS of allN-term sequences of results which are compatible with the given evidence. We generalize to the information gain method of Kullback.     

Gamma Ray Generation Through a 1.064 μM Laser Beam

We are exploring to process nuclear waste through nuclear transmutation method with ray irradiation. The ray employed for transmutation is generated in the way of Compton backscattering. Preliminary experiment is being developed on the NewSUBARU storage ring providing an electron beam with energy of 1 GeV, and 17.6 MeV ray will be generated through a head-on collision of the electron beam and a 1.064 m laser light. ray flux about the present experiment is predicted theoretically. A planned scheme for promoting the flux is also introduced, As well as the maximum laser power available for the storage ring is discussed.     

High-spin states and band structures in the doubly odd <Superscript>136</Superscript>La nucleus

High-spin states of ¹³⁶La have been investigated with the reaction ¹³⁰Te( ¹¹B, 5n) at a beam energy of 60 MeV. The level scheme with three collective bands has been updated with spin up to 20 . The observed h_11/2 h_11/2 band shows -instability with increasing spin according to the TRS calculations. The band crossing and the signature splitting and inversion have been discussed. Other two collective bands based on 12^-and 16⁺ levels were proposed as oblate deformation with -60^°. They most probably originate from four- and six-quasiparticle configurations, that is, h_11/2 g_7/2h_11/2² and g_7/2 g_7/2²d_5/2h_11/2² respectively.