Southern Connecticut State University

                                   Earth Science X-ray Analysis Laboratory

The Southern Connecticut State University Department of Earth Sciences maintains an x-ray analysis laboratory for the purpose of characterizing earth materials.  The laboratory houses a fully automated Spectro Analytical energy-dispersive spectrometer and a Rigaku x-ray powder diffractometer.  The primary function of the laboratory is to support student-based research in the earth sciences and provide hands-on learning experiences for undergraduates.  Students and researchers from other departments and universities, government agencies, or industry are welcome to use the facility for a  nominal fee to partially defray the costs associated with sample preparation and equipment maintenance.

X-ray Fluorescence Spectroscopy

X-ray fluorescence is used to obtain the chemical composition of materials (rocks, sediments, soils, water).  Samples are irradiated by a high intensity x-ray beam which causes electrons to be dislodged from the inner-shell orbitals of atoms in the sample.  Replacement of these electron vacancies with electrons from the outer electron shells causes the atoms to emit (fluoresce) x-rays that have a characteristic energy (or wavelength) for each element in the sample.  The intensity of the characteristic fluorescent x-rays is proportional to the concentration of the element in the sample allowing for quantitative evaluation of the chemical composition of the sample.

Spectro X-Lab 2000  Polarization Energy Dispersive X-ray Fluorescence Spectrometer

X-ray Tube:  Varian EG-60,  60 kV, 400watt, end-window Pd tube, Oil cooled 

Sample chamber:  Vacuum, N₂ flush,  He flush, or Air path

Detector:  Röntec LN₂ cooled Si(Li), 12.5 mm² active area, FWHM (MnKa) = 152eV @ 10,000 cps, 8mm DURA-Be window

Samples:  Solids (pressed pellets, powders, granules, glasses), or liquids;  32mm diameter sample holder,  20 position sample changer

Element Range:  Na through U at concentrations from sub-ppm to 100%

Software:  Spectro X-LabPro package (fundamental parameters (Turboquant), Lucas-Tooth and Price, extended Compton,  Alpha coefficient correction)

Target

Type

Analyte Elements

Al₂O₃

Barkla polarization target

K-lines: Zr –Nd,    L-lines: Th-U

BC₄

Barkla polarization target

K-lines: Ti-Mo,    L-lines:  Cs-U

HOPG (graphite)

Bragg scattering target

K-lines: Na-Zn

Mo

Secondary target

K-lines: Cr-Y,    L-lines: Hf-U

Co

Secondary target

K-lines: K-Mn,   L-lines: Ag-Sm

Si

Secondary target

K-lines: Na-Al  

Al

Secondary target

K-lines:Na-Mg

Ti

Secondary target

K-lines: Na-Ca,  L-lines: Rb-Sb

Analytical Methods

XRF links

X-ray Diffraction

X-ray powder diffraction is used to determine the inter-atomic spacings of powdered or polycrystalline materials.  The data are used to evaluate the presence of crystalline phases, and uniquely identify crystalline materials based on their structure (arrangement of atoms). 

Rigaku  Geigerflex  X-ray Powder Diffractometer

X-ray generator:  DXG1 50kV, 1.5W

X-ray Tube:  AEG FK60-10,  60 kV, 2kW, end-window Cu tube

Goniometer:  CN2155D2 horizontal goniometer

Detector:  SPC-10 Sealed proportional counter, graphite monochromator

Sample Preparation Equipment

SPEX  Mixer Mill   Al-ceramic and Tungsten carbide grinding containers

Sepor ceramic jaw crusher

Bico VD (chipmunk) jaw crusher

SPECAC  25 ton manual hydraulic press with 32mm  stainless steel and tungsten pellet dies

Rocklabs bench top ring mill with tungsten carbide grinding container

Rock saws

Rock polishers

Mettler  H10T analytical balance

Denver Instruments analytical balance

For additional information regarding the Earth Science X-ray analysis laboratories capabilities and analytical costs, please contact Dr. Thomas Fleming (203-392-5837)

Created and Maintained by Thomas Fleming  Last update 08/10/2005

x-ray fluorescence, xray fluorescence, XRF, EDXRF, SPECTRO, X-Lab 2000, xlab2000, xlab 2000, energy dispersive XRF, wave length dispersive XRF,

Geology, Earth Science, Geological Science, geological sciences, Petrology, Mineralogy