Beam
drift (concurrent integration using beam current aperture) Count time
(normalized to ____ seconds)
Detector/amplifier dead-time losses Standard
count drift (linear interpolation in real time) Spectral
interferences (quantitative, iterated)EXPERIMENTAL CONDITIONS
Electron Microprobe Analysis
RUN FILE : ______________________________________ DATE : ________________________
Laboratory Manager :
John J. Donovan
Department of Geological Sciences
210 Cascade Hall
University of Oregon
Eugene, OR, 97403
(541) 346-4632 (voice)
(541) 346-4692 (FAX)
Instrumentation :
Analyses were performed on a five spectrometer Cameca SX-51 wavelength dispersive electron beam microprobe, of 40.0 degree take-off angle. The WDS spectrometers include two high pressure and three low pressure P-10 flow proportional detectors and assorted analyzing crystals (LiF, PET, ADP, TAP, W/Si and NiCrBN). The instrument also includes :
- 138 eV resolution, 30K cps, Si(Li) EDS (energy dispersive)
detector
- reflected and transmitted light optics (400X) with crossed
polarizer (0.7 u depth)
- SE (secondary electron) detector (63 to 10000X magnifications)
(topography)
- BSE (backscattered electron) detector (topography and atomic
number contrast)
- CL (catho-luminescence) detector (trace element and crystal
defect imaging)
- oxygen micro-leak and LN2 dewer for carbon contamination
reduction
- 0.5 u stage resolution and reproducibility (X, Y and Z)
On-line data acquisition and reduction was performed by Probe for Windows © software written by John Donovan, running on a DELL ® Pentium PC running at 133 Mhz with a 1 GB Mb hard disk drive for data storage and retrieval and 32 MB of RAM. Output was to an HP Laserjet 4M+ printer and/or an HP 1600CM color printer.
Comments :
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
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Analyzed Elements :
Operating Conditions :
____ KeV kilovolts (corrected for bias voltage drop)
____ nA nano-amps (sample current as measured on MgO)
____ sec seconds (typical count time for unknowns)
____ Å angstroms (carbon coat thickness using Spec-Pure ®
evaporated carbon)
____ m microns (typical beam spot
size)
____ m microns (maximum analytical
volume diameter for light elements)
X-ray intensities were corrected for :
Beam
drift (concurrent integration using beam current aperture)
Count time
(normalized to ____ seconds)
Detector/amplifier dead-time losses
Standard
count drift (linear interpolation in real time)
Spectral
interferences (quantitative, iterated)
Off-peak backgrounds ( linear interp., aver., high, low, expon.)
MAN
backgrounds (Mean Atomic Number, iterated, non-linear fit)
PHA (Pulse
Height Analysis)
Matrix Corrections :
Oxygen
calculated by stoichiometry to cations
Oxygen
measured
Phi-Rho-Z
ZAF
Bence-Albee (constant)
Bence-Albee (linear)
Bence-Albee (polynomial)
Calibration curve (multi standard)
Absorption :
PHILIBERT (FRAME)
HEINRICH/AN. CHEM.
HEINRICH/1985 MAS [Heinrich, Microbeam Analysis--1985, 79]
LOVE/SCOTT
-- 1983 [e.g., Love & Scott, J. Phys. D. 11, 1369 (1978)]
LOVE/SCOTT
I -- 1985 [Sewell, Love & Scott, J.Phys.D. 18, 1233 (1985)]
LOVE/SCOTT
II -- 1985 [Sewell, Love & Scott, J.Phys.D. 18, 1233 (1985)]
PACKWOOD/BROWN XRS [Brown-Packwood, X-ray Spec. 11, 187 (1982)]
BASTIN
1984/XRS [e.g., Bastin et al., X-ray Spec. 13, 91 (1984)]
ARMSTRONG
MAS [Armstrong, Microbeam Analysis--1984, 208;--1982, 175]
Atomic number :
DUNCUMB/REED(FRAME)
LOVE/SCOTT
BROWN/BASTIN/JTA PHI(PZ)
Backscatter :
HEINRICH
LOVE/SCOTT
Mean ionization potential :
BERGER/SELTZER
DUNCUMB/DA
CASA
Phi-Rho-Z equation :
REUTER
LOVE/SCOTT
NONE
Fluorescence Correction :
REED/ARMSTRONG (modified for M line and relative ionization)
REED/ARMSTRONG (un-modified)
REED/ARMSTRONG (modified for M line only)
Mass Absorption Coefficients :
LINEMU.DAT (Henke, 1985)
CITZMU.DAT
(Heinrich, 1981)
Empirical
(Selected MACs from Pouchou)
Spectral Interferences :
Interference Corrections Applied to Elements
_____________________________
Area Peak Factors :
Area-peak factors from Bastin/Donovan
Volatile Element Correction :
Volatile Element Correction Applied to Elements _______________
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