775 research outputs found

    Isotope shifts of 6s5d 3^3D-states in neutral Barium

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    Laser spectroscopy of the low lying 1^1P and 3^3D states in atomic barium has been performed. This work contributes substantially to the development of an effective laser cooling and trapping for heavy alkaline earth elements and aims in particular for a better understanding of the atomic wave function of these systems. Isotope shifts and hyperfine structures are ideal probes for the wave functions at the position of the nucleus. This is essential input for a theoretical evaluation of the sensitivity to fundamental symmetry breaking properties like permanent electric dipole moments. We report the first isotope shift measurements of the 3^3D1,2_{1,2}-1^1P1_1 transitions. A deviation of the King plot from its expected behavior has been observed. Further we have optically resolved the hyperfine structure of the 3^3D1,2_{1,2} states.Comment: 7 pages, 7 figure

    Magneto optical trapping of Barium

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    First laser cooling and trapping of the heavy alkaline earth element barium has been achieved based on the strong 6s2^2 1^1S0_0 - 6s6p 1^1P1_1 transition for the main cooling. Due to the large branching into metastable D-states several additional laser driven transitions are required to provide a closed cooling cycle. A total efficiency of 0.4(1)⋅10−20.4(1) \cdot 10^{-2} for slowing a thermal atomic beam and capturing atoms into a magneto optical trap was obtained. Trapping lifetimes of more than 1.5 s were observed. This lifetime is shortened at high laser intensities by photo ionization losses. The developed techniques will allow to extend significantly the number of elements that can be optically cooled and trapped.Comment: 4 pages, 5 figure

    Geology and Ground-Water Resources of Neosho County, Kansas

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    Neosho County has an area of 576 square miles and is within the Osage Plains section of the Central Lowlands province of eastern Kansas. Sedimentary rocks of Cambrian, Ordovician, Devonian(?), Mississippian, Pennsylvanian, Tertiary, and Quaternary ages overlie the Precambrian basement complex, and they have a thickness of 2,100 feet. Rocks exposed in the county are of Pennsylvanian, Tertiary, and Quaternary ages that attain a thickness of 700 feet. Structure is controlled by the Prairie Plains Monocline in which the exposed Pennsylvanian rocks dip northwest at about 20 feet per mile. Wells in consolidated rocks of Pennsylvanian age yield less than 1 gallon per minute of water from some limestone and shale aquifers to more than 30 gallons per minute from sandstone aquifers. The water from the consolidated aquifers is highly mineralized, but the sandstones tend to yield a softer, less mineralized water. Wells within unconsolidated Pleistocene alluvial deposits yield up to 30 gallons per minute. The chief use of the ground water is for domestic and stock purposes, whereas all municipal systems use treated surface water. The estimated total use of ground water in 1961 was 109 million gallons (334 acre-feet)

    Absolute frequency measurement of the 7s2^2 1^1S0_0 −- 7s7p 1^{1}P1_1 transition in 225^{225}Ra

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    Transition frequencies were determined for transitions in Ra in an atomic beam and for reference lines in Te2_2 molecules in a vapor cell. The absolute frequencies were calibrated against a GPS stabilized Rb-clock by means of an optical frequency comb. The 7s^2\,^1S0_0(F = 1/2)-7s7p\,^1P1_1(F = 3/2) transition in 225^{225}Ra was determined to be 621 042 124(2) 621\,042\,124(2)\,MHz. The measurements provide input for designing efficient and robust laser cooling of Ra atoms in preparation of a search for a permanent electric dipole moment in Ra isotopes.Comment: Accepted for publication in the rapid communication of Physical review

    Radium single-ion optical clock

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    We explore the potential of the electric quadrupole transitions 7s\,^2S_{1/2} - 6d\,^2D_{3/2}, 6d\,^2D_{5/2} in radium isotopes as single-ion optical frequency standards. The frequency shifts of the clock transitions due to external fields and the corresponding uncertainties are calculated. Several competitive A^ARa+^+ candidates with A=A= 223 - 229 are identified. In particular, we show that the transition 7s\,^2S_{1/2}\,(F=2,m_F=0) - 6d\,^2D_{3/2}\,(F=0,m_F=0) at 828 nm in 223^{223}Ra+^+, with no linear Zeeman and electric quadrupole shifts, stands out as a relatively simple case, which could be exploited as a compact, robust, and low-cost atomic clock operating at a fractional frequency uncertainty of 10−1710^{-17}. With more experimental effort, the 223,225,226^{223,225,226}Ra+^+ clocks could be pushed to a projected performance reaching the 10−1810^{-18} level.Comment: 20 pages, 1 figur

    Dual Magnetic Separator for TRIμ\muP

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    The TRIμ\muP facility, under construction at KVI, requires the production and separation of short-lived and rare isotopes. Direct reactions, fragmentation and fusion-evaporation reactions in normal and inverse kinematics are foreseen to produce nuclides of interest with a variety of heavy-ion beams from the superconducting cyclotron AGOR. For this purpose, we have designed, constructed and commissioned a versatile magnetic separator that allows efficient injection into an ion catcher, i.e., gas-filled stopper/cooler or thermal ionizer, from which a low energy radioactive beam will be extracted. The separator performance was tested with the production and clean separation of 21^{21}Na ions, where a beam purity of 99.5% could be achieved. For fusion-evaporation products, some of the features of its operation as a gas-filled recoil separator were tested.Comment: accepted by Nucl.Instr. Meth., final versio

    Microalgae: Bioremediation of effluents with microalgae strains.

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    Microalgae strains capable of promoting the biological reduction of the organic and inorganic loads of effluents, achieving high biomass productivity and assimilating CO2 emitted by agro-industrial production processes.TC 214
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