SEM EDS

"Energy-dispersive X-ray spectroscopy (EDS, EDX, or XEDS)"

List of EDS manufacturers:

• • EDAX
  • Website]
  • Oxford Instruments
  • Website]
  • Noran Instruments (now Thermo Scientific)
  • Princeton Gamma-Tech (PGT, now Thermo Scientific)
  • Bruker
  • Website]
  • Evex (Kevex?)
  • "To enjoy this site you'll need to update your Flash Player. It's easy, painless and will take just a moment… "
  • haha never buying your products
  • Link Analytical
  • e2v Sirius

Typical systme:

• • Thin window (Be, C, B)
  • SiLi crystal
  • FET pre-amplifier
  • Vacuum
  • Cold finger
  • Pre-amplifier
  • Amplifier
  • MDA electronics (“multi channel analyzer”)

Detector

Styles

• • Si-Li
  • Silicon Drift Detector (SDD)

Si-Li

Operates at LN2 temps. If operated at room temp it will be destroyed

SDD

"SDD detectors operate at a few tens of degrees below zero"

Window

Styles [epmalab]:

• • Be foil
  • Supported window
  • Windowless

Be foil

"The most common EDS detector window has been made of Be foil ~7.6 um (0.3 mil) thick. It allows good transmission of X-rays above ~ 1 keV. It is strong enough to withstand venting to atmospheric pressure, and opaque to optical photons." [epmalab]

Supported window

"For transmission of light element X-rays (<1 keV), windows ~0.25 um thick of BN, SiN, diamond or polymer are used. They must use supporting grids to withstand pressure differentials; the grid (e.g., Si or Ni) takes up about 15% of the area, but thin enough that low energy X-rays pass through." [epmalab]

Ultra Thin Window (UTW)

made of:

• • Polymide ref]
  • "poly-vinyl formal (FORMVAR), butvar, parylene, kevlar, polypropylene, lexan or polyimide" ref]

Windowless

"no film, and there is a turret that allows swapping with a Be window. Difficult to use as oil or ice can coat the detector surface" [epmalab]

Gamma Spectacular

[1]]

How hard would it be to use this as EDS controller?

Model comparison

Image	Vendor	Model	Year	Features	List price	Ask price	Manual	Schem	SW
	EDAX	Genesis Spectrum	2006				Yes]		[Yes] | ]

References

• • [http:www.charfac.umn.edu/instruments/eds_on_sem_primer.pdf http://www.charfac.umn.edu/instruments/eds_on_sem_primer.pdf]]]
  • Has a nice CAD drawing explaining the components of real EDS detectors
  • [http:epmalab.uoregon.edu/pdfs/Electron Beam MicroAnalysis-Geol_619-8.ppt http://epmalab.uoregon.edu/pdfs/Electron Beam MicroAnalysis-Geol_619-8.ppt]]]

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