SCANNING ELECTRON MICROSCOPY
Scanning Electron Microscopy (SEM) magnifies a specimen using a high energy beam of electrons. When the beam of electrons hits the sample, it causes secondary electrons to be released from the sample which are detected to provide an image based off the topography of the surface. When beam of electrons hit the sample surface, X-rays are also released from the surface of the sample that carry a unique signature that are specific to elements found in the sample. These X-rays are detected with Energy Dispersive Spectroscopy (EDS) detector. This provides data about the chemical composition of the sample and provides additional data about the features that are observed in the SEM micrographs.
Vollmer-Gray’s laboratory is equipped with a FEI Quanta 200 Scanning Electron microscope with Energy Dispersive X-ray Spectrometer (EDS). The microscope can be operated in regular high-vacuum, low-vacuum and ESEM modes for imaging many varieties of samples. The Quanta is equipped with a range of detectors including Secondary Electron (SE), Back Scattered (BSE), Energy Dispersive X-ray analysis (EDS), an internal TV camera (CCD) and a range of special detectors for using the SEM in LV or ESEM mode. The microscope is equipped with large chamber, enabling the analysis of large specimens (without sectioning the evidence).