Electron Probe X-Ray Microanalyzer (EMPA) Laboratory

Principles

Electron Probe X-ray Microanalyzer

X-ray signal

Other signals

Our Equipment

 

  Crystal 2d (A) Range of elements  
  TAP 25.757 F ~ P (Ka )  
  LIF, LIFH 4.027 Sc ~ Rb (Ka)  
  PETJ, PETH 8.742 Si ~ Mn (Ka)  
  LDE1 60 C ~ F (Ka)  
  LDE2 95 B ~ N (Ka)  

Detection Limits depends on the element of interest and its matrix, (e.g. 6 ppm for Fe, <30 ppm for Se, etc.). Detection limit in weight percent for a single analysis line with a confidence of 99% (assumes 3 standard deviations above the background, JEOL).

 

Equation

Where :          ZAF    is the ZAF correction factor for the sample matrix

                        I is the raw count rate on the analytical standard and unknown samples

                       Cstd is the pre-determined concentration in the standard

Spatial resolution varies from ~3 um in diameter for small particles to mm2 level for raster areas.

Penetrating depth can be varied for film/coating analyses, varying from submicron to over 10 um depending on the element of interest and its matrix.

Liquid nitrogen free, high count-rate silicon drift detector (SDD) EDS spectrometer.