Instrumentation

• Scanning Electron Microscopes (SEMs) The NMARL has the following SEMs available: JEOL 5800 with a NORAN Instruments energy-dispersive x-ray detector system, GW Electronics enhanced backscatter detector, and a NORAN Instruments Voyager IV microanalysis system and JEOL 5800 LV (LV is for manual control of the vacuum system to obtain a low vacuum) with a PRINCETON GAMMA TECH (PGT) SPIRIT Instruments energy-dispersive x-ray detector system and microanalysis system. Elements higher than atomic number 6 can be analyzed with an accuracy of 0.1 wt%. Standard and standardless quantification is available. The JEOL 5800 LV also has a HKL TECHNOLOGY electron backscatter diffraction (EBSD) system. The system is composed of a detector, essentially a digital camera charge-coupled device (CCD) chip placed behind a phosphor screen and interfaced with SEM. EBSD allows crystallographic information to be obtained from samples in the SEM.
  
  QEMSCAN is a surface analytical tool that allows for automated quantitative evaluation of minerals by matching spectra collected on the sample with a predefined lookup table then assigns and quantifies the mineral phases or chemical compositions on a particle-by-particle basis, with details down to the submicron resolution at relatively short time scales. The main components of the system include a Carl Zeiss motherboard SEM, four high-speed BRUKER energy-dispersive x-ray detector system silicon drift detectors (SDDs), an automated sample stage, a signal-processing unit, and proprietary software for mineral classification and quantification.
  
  The main advantages of the system are high speed and digital images of the analyzed samples. It typically collects spectrum at a point for a total of 1000 x-ray counts in about 5 milliseconds; thus it can process about 100,000 spectra in 1 hour. Typical output data include digital images of samples which use colored pixels to represent different mineral phases, mineralogical composition and morphology, mineral grain-size distributions, and pixel-by-pixel elemental information.
  
  SEM Techniques
  
  
• X-Ray Fluorescence (XRF) Rigaku ZSX PRIMUS II is a wavelength-dispersive x-ray system that is good for elements above atomic number 6 with accuracies that can be attained to the ppm level (traditional reporting to 0.1 wt%). Standards must be available for elements to be quantified.
  
  XRF Techniques
  
  
• X-Ray Diffraction (XRD)
  BRUKER AXS D8 ADVANCE is a state-of-the-art research-grade XRD instrument for conducting phase identification, ab initio structure determination, and quantitative phase analysis (QPA).
  
  XRD Techniques