Search results for "Quadrupole"

Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy

2018

Until recently, ground-state nuclear moments of the heaviest nuclei could only be inferred from nuclear spectroscopy, where model assumptions are required. Laser spectroscopy in combination with modern atomic structure calculations is now able to probe these moments directly, in a comprehensive and nuclear-model-independent way. Here we report on unique access to the differential mean-square charge radii of ^{252,253,254}No, and therefore to changes in nuclear size and shape. State-of-the-art nuclear density functional calculations describe well the changes in nuclear charge radii in the region of the heavy actinides, indicating an appreciable central depression in the deformed proton densi…

Complexes of organometallic compounds. XLIX. A Mössbauer-zeeman spectroscopic study of glycylglycinato-O,N,N(2−) diphenyltin(IV), and the point-charg…

1978

Mössbauer spectroscopy of mono-organotin(IV) derivatives

1974

Abstract The Mossbauer parameters isomer shift, δ, and quadrupole splitting, ΔE, of mono-organotin compounds insofar investigated have been collected and tabulated. It is demonstrated that isomer shifts consistently depend on ligand electronegativities and coordination numbers, from which it is deduced that RSn IV behave much more as Sn IV rather than R 2 Sn IV and R 3 Sn IV derivatives. The changes of δ for RSn IV are then interpreted by hypotheses analogous to those advanced for Sn IV and its adducts and complexes. It is also inferred that in RSn IV compounds there is a consistent s-character in all tin-ligand atom bonds.

The hydrolysis of Me2SnIV and Me3SnIV moieties monitored through 119Sn Mössbauer spectroscopy

1991

Abstract The 119 Sn Mossbauer parameters δ, isomer shift, and Δ E , nuclear quadrupole splitting, have been determined in frozen aqueous solutions of Me 2 Sn IV and Me 3 Sn IV moieties at varying pH. The resulting functions n versus pH (where n is the average number of protons released per mole of the organotin aquocation) agree satisfactorily with functions from potentiometry. The structures of the aquocations, as well as of the hydroxides, and of the mono-hydroxo complex [Me 2 Sn(OH)(OH 2 ) n ] + , are correlated to the Δ E exp data by point-charge model calculations.

Mössbauer effect study of the electronic ground state of iron(II) in [57FexM1−x(bipy)3](ClO4)2 (M = Mn, Ni, Zn) and [57FexM1−x(phen)3](ClO4)2 (M = Ni…

1980

Earlier work in our laboratory on the effect of metal dilution on the 5T2(Oh ⇌ 1A1(Oh) equilibrium in polycrystalline spin crossover systems of iron(II) has shown that the relative stability of the high spin state, 5T2(Oh), at a given temperature, increases markedly with decreasing iron concentration. These results have initiated the present work. Using 57Fe Mossbauer spectroscopy, we have investigated the electronic ground state of iron(II) in the highly diluted solid solutions [FexM1−xL3] with L = bipy, M = Mn, Ni, Zn, x ≲ 0.005 and L = phen, M = Ni, Zn, x ≲ 0.005. Although the critical field potential (Vc) of the pure iron complexes, which are known to be low spin, is reported to be not …

Nuclear moments and the change in the mean square charge radius of neutron deficient thallium isotopes

1992

The hyperfine structure, isotope and isomeric shifts in the atomic transition 6p 2 P 3/2−7s 2 S 1/2, λ=535 nm have been measured for theI=7 andI=2 states of190, 192, 194, 196Tl; theI=1/2 andI=9/2 states of191Tl and the I=7 isomer of188Tl. The thallium isotopes were prepared as fast atomic beams at the GSI on-line mass separator following fusion reactions and — in some cases — subsequentβ-decay. The nuclear dipole moments, electric quadrupole moments and the change in the nuclear mean square charge radius are evaluated. Theuu-isotopes show an isomeric shift which changes sign between192Tl and194Tl.

Isotope shifts and hyperfine structure in the transitions of stable calcium isotopes and calcium-41

1998

Isotope shifts and hyperfine structure in the 4s2 1S0 → 4s4p 1P1 and 4s2 1S0 → 4s4d 1D2 transitions of calcium have been measured with high-precision laser spectroscopy. Calcium atoms in an atomic beam were excited with single-frequency cw dye and titanium sapphire lasers and then photoionized with the 363.8 nm or 514.5 nm line of an argon ion laser. The resulting ions were analyzed and detected with a quadrupole mass spectrometer. Isotope shifts for all stable calcium isotopes and the radionuclide 41Ca have been measured in both transitions. The corresponding field shift and specific mass shift coefficients as well as hyperfine structure constants for the isotopes 41, 43Ca have been derive…

Laser spectroscopy of neutron deficient lead and thallium isotopes: Systematics of nuclear radii in the Z = 82 region

1989

Publisher Summary The high sensitivity achievable in laser spectroscopic methods allows the extraction of nuclear quantities even of artificially produced short-lived nuclides far off from nuclear stability. By analyzing the hyperfine structure and the isotope shift magnetic dipole moments, the electric quadrupole moments and the change of the nuclear charge radius can be studied. This chapter describes an experiment that was carried out at the GSI on-line mass separator using collinear fast atomic-beam laser spectroscopy. Radioactive lead and thallium isotopes were produced by bombarding natural tungsten targets with oxygen beams. For the lighter thallium isotopes, a tantalum target was us…

Ultratrace analysis of calcium with high isotopic selectivity by diodelaser resonance ionisation mass spectrometry

1997

A resonance ionisation mass spectrometer for the ultratrace determination of calcium isotopes is presented. It achieves high overall efficiency, ultra-high isotopic abundance sensitivity of more than 1010 and complete suppression of isobars. The system can be used for isotope ratio studies on stable and long-lived trace isotopes with the final goal of radiodating via 41Ca-determination. For the different applications optical one-, two- or three-step resonance excitation and subsequent ionisation is applied using simple and inexpensive diodelasers. Additional mass analysis is accomplished in a commercial quadrupole mass spectrometer. The experimental set-up and first results on synthetical a…

Kompakti automatisoitu laser-ionisointijärjestelmä

2011

In an experimental nuclear physics off-line systems are often used in situations where acceleration energies are relatively small. Main benefits are low price and meager radiated laboratory enviroments. In this master’s thesis I discuss mostly about automation which was used in our off-line system. The system was built at the Ion Guide Separator On-Line facility (IGISOL) in Jyväskylä University. The automation set up was made with the Phoenix Contacts inline terminals, which were programmed by using the Labview program. The system consists of thermistor, skimmer handling, mirror handling, gasline parts per billion (ppb) mixing and quadrupole mass spectrometer measurement. There were major p…