K.V. Zolotarev

Scanning SR-XRF beamline for analysis of bottom sediments

Abstract The XRF beamline at the VEPP-3 (Budker INP, Novosibirsk, Russia) storage ring was modified for the performance of scanning analysis. A description and parameters of this facility are presented in the current paper. The initial results of testing of scanning analysis of bottom sediments from Lake Baikal are also presented. A spatial resolution of the scanning analysis is 0.1–1xa0mm which corresponds to 2–50 years of resolution. Such a scanning analysis of lake sediments provides high quality data as a requirement for paleoclimate reconstructions.

Application of synchrotron X-ray fluorescent analysis to studies of the records of paleoclimates of Eurasia stored in the sediments of Lake Baikal and Lake Teletskoye

Abstract Multi-element SRXRF of sediments of Lake Baikal (East Siberia) with samples taken at 10xa0cm intervals from a core spanning the last 250xa0ky revealed nine peaks of “warm” signals like Sr/Ba(Rb,Cs) and U/Th corresponding to Oceanic Isotope Stages 1,3,5a,5c,5e,7 and 9, and six peaks of “cold correlator” corresponding to OIS 2,4,5d,6 and 8. A slab (1500–2200xa0mm below the sediment surface) taken from another core was studied by scanning SRXRF. This interval corresponds to the Siberian Karga interstadial (OIS3, 24–58xa0kyxa0BP). It hosted two peaks of diatom algae frustulles, indicators of warmer climates. The scanning was performed at a temporal resolution of ca. 50xa0yr. Ratios of concentrations like Sr/Rb(Ba,Cs,Ti,Fe) (Nucl. Instr. and Meth. A 448(1–2) (2000) 384; Nucl. Instr. and Meth. A 448 (1–2) (2000) 400) appeared to be more sensitive proxies of warm climates, compared to total diatoms, and revealed at least six pronounced cycles of abrupt warming and cooling episodes, each lasting a few millennia. These fluctuations may reflect a response of the catchment basin of the Lake Baikal to abrupt global climate cycles recorded in the ice of Greenland and in the sediments of North Atlantic (Nature 364 (1993) 142; Science 278 (1997) 1257; Science 288 (2000) 128). SRXRF applied to the sediments of Lake Teletskoye (West Siberia, Altai Mountains) of the last 600xa0yr provided a temporal resolution of 1.2–1.8xa0yr. The profiles of a few elements like K, Ca, Ti, Fe, V revealed oscillations with a periodicity of 9.4xa0yr over the time interval between years 1400 and 1600. Oscillations faded out after the cooling of 1600–1700 (The Maunder interval). Periodic oscillations between years 1400 and 1600 seem to correspond to periodic changes in the height of oceanic tides (9xa0yr (PNAS 94 (1997) 8321; PNAS 97 (2000) 3814)) rather than to the solar activity cycles (periodicity of 11xa0yr).

Synchrotron radiation X-ray fluorescence analysis of VEPP-3 of the bottom sediments of Lake Baikal to perform a paleoclimatic reconstruction

Abstract Data on the element composition of 107 samples collected by drilling down to a depth of 11 m on the bottom of the Academican Ridge, Lake Baikal, are reported. Some experimental aspects of SRXFA on VEPP-3 appropriate for Baikal sediments are also described. The procedure of energy scanning was used to correct the data on Rbue5f8Mo concentrations in samples with significant U contents. A variant of geochemical paleoclimatic interpretation of these data has been carried out using additional U, Th/U and biogenic silica distribution. “Warm” and “cold” periods of climate with the corresponding mean contents of elements have been distinguished. The greater contents of almost all the elements during “cold” periods as compared to “warm” ones are observed. Compared to terrigeneous mud from the Central Depression of Lake Baikal, the total element contents of St. 15 are also elevated.

Determination of the concentrations and distributions of rare-earth elements in mineral and rock specimens using the VEPP-4 synchrotron radiation

Results are presented on X-ray fluorescence determination of the K-series of rare-earth elements (REE) in rocks using synchrotron radiation (SR) from the VEPP-4 storage ring. In a direct, instrumental determination, the detection limit is 5 × 10−5 %. The procedure for chemical preconcentrating which allows the detection limit to be reduced to 10−6 % is described. The SRXFA technique has also been employed to study the spatial distribution of REE in rock specimens by scanning with an SR beam.

Biological monitoring of meadow moths by SR-XRF technique

Abstract The study of the elemental composition of flying insect bodies is one way to obtain data about environmental conditions in certain regions and about characteristics of insect remote migrations. The results of an analysis of meadow moth bodies from different regions and populations using synchrotron radiation X-ray fluorescence analysis are presented. Comparisons with other techniques of analysis are carried out. The application of scanning X-ray fluorescence elemental analysis allows one to determine the distribution of different elements in the body of an individual moth.

Synchrotron radiation and free electron laser activities at SSRC

Abstract In the last decade the Siberian SR Centre has implemented a wide program of SR and FEL research in cooperation with various research centres and institutions in Russia and abroad. The report illustrates this program, including joint experiments with the use of SR and FEL sources available at the Budker Institute of Nuclear Physics (INP), the implementation of new joint projects in Novosibirsk and at other centres, as well as the delivery of equipment designed and fabricated at the Budker INP or in collaboration with the Russian industry. Some technical information about the SR storage rings, wigglers, undulators and free electron lasers which are being constructed, used or developed at Budker INP is given as well.

Scanning synchrotron radiation X-ray fluorescence trace element analysis of microlayers of FeMn nodules; new data on ore forming processes in the Ocean

Abstract Scanning synchrotron radiation X-ray fluorescence analysis was used for studying base and trace element distributions in submarine Feue5f8Mn nodules from the eastern tropical Pacific. The element background contents in surface layers of spherical (hydrogenous) and ellipsoidal (diagenetic) Feue5f8Mn nodules are measured. The concentration of elements determined to be in internal layers is different from that in surface layers. This suggests changes of the environment in the past.

Synchrotron Radiation X‐Ray Fluorescence Study of the Compositional Homogeneity of a Sediment Core from Lake Baikal

The first 100 m core-drill sample which was obtained by drilling from a boat frozen in the ice of Lake Baikal (BDP-93-1) was quantitatively investigated by synchrotron radiation XRF to investigate the trace element contents. The ability to change the energy of the exciting monochromatic beam and the high intensity of the radiation allow the investigations to be performed with detection limits of 1-2 ppm for groups of geochemically important elements, Rb-Nb, Ba-Nd, and for milligram samples. The results showed geochemical inhomogeneity in the 61-65 m range of the core-drill, characterized by higher ratios of Sr to Rb, Sr to Y and Sr to Ce compared with other sections of the core.

Focusing parabolic pyrolytic graphite X-ray monochromator

Abstract Results of the experimental testing of the focusing parabolic pyrolytic graphite X-ray monochromator on the wiggler synchrotron radiation beamline of the VEPP-3 storage ring (2 GeV, 100–150 mA) are presented. The monochromatization and the focusing of X-radiation in both vertical and horizontal directions are provided by the optical properties of the parabolic surface of revolution of the properly shaped pyrolytic graphite crystal attached to the parabolic-machined brass support. A single crystal is a half of the parabolic surface of 160 mm long and of ∼ 19 mm minimal focus length. The sagittal radii are changed from 10 to 30 mm. The available photon energy range is 7–20 keV on the first reflection harmonic. The second reflection order is still comparable with the first one in intensity: due to this fact the energy range can be extended up to 40 keV. Changing the energy of the monochromatized X-radiation is accomplished by a simple vertical shift of the monochromator.

Scanning X-ray fluorescence microanalysis of phosphorites from the underwater mountains of the Pacific

Abstract The application of scanning X-ray fluorescence microanalysis using a synchrotron radiation beam from the VEPP-3 storage ring to study the distribution of microelements in samples of phosphate—ferrous—manganese nodules from the underwater mountains of the north-western Pacific is described. The distribution of Ca, Mn, Fe, Cu, Zn, Rb, Sr, Y, Zr and Mo at concentrations of up to 10 ppm and spatial resolution up to 50 μm on the boundary of the phosphate and ferrous—manganese sections was studied. The concentrations of I, Ba, La and Ce, with detection limits of 20 ppm at separate points of 50 × 50 μm 2 area, were determined along a profile from the periphery to the centre of the samples.