Oxford Instruments X-Max Silicon Drift Detector for Energy and Wave Dispersive X-Ray Spectroscopy

Energy Dispersive X-Ray analysis is an important tool for chemical characterisation and elemental analysis. During FESEM analysis, the emission of characteristic X-Rays is stimulated by the high-energy electron beam. This X-Ray energy is then converted to a voltage signal by the Silicon Drift Detector. Signal processing generates a spectrum, allowing the identification of elemental constituents in the sample. Quantitative analysis can be performed on clean, polished, flat samples in which peak heights or areas are compared in the unknown with a standard material.

Wave Dispersive X-Ray Spectroscopy differs from EDX in that it uses the diffraction patterns created by light-matter interaction as its raw data. WDX has a much finer spectral resolution than EDX and as such allows spectrum lines to be resolved which are obscured by peak overlaps in EDS. WDX is generally used to detect trace elements (typically <10%).

Technical Specifications:

  • Unique single sensor large area SDD sensors
  • Up to 50mm² active area (100mm2 sensor size)
  • Count rates > 500,000 cps
  • Throughput > 200,000 cps
  • MnKα guaranteed @ 124eV, CKa guaranteed @ 48eV
  • Vacuum enclosed sensor to reduce oxygen absorption
  • Only one pulse processing channel required
  • Pile up correction software for accurate analysis at high count rates
  • WDX:
  • Fully focusing spectrometer using 210mm Rowland circle and 2theta range of 33° to 135°.
  • Five diffracting crystals on a six position, computer controlled turret, changeable at any position. For analysis of all elements down to Be (Z = 4). Crystals include: LiF. PET, TAP, LSM60N and LSM200.Spectral resolution as low as 2eV making the separation of closely spaced X-ray lines simple
  • Excellent detection limits, which are less than 100ppm for many elements
  • Accurate quantitative analysis using the XPP matrix correction algorithm
  • Proven results on many types of samples, including light elements, and high spatial resolution using low beam currents (<5nA).