Interactive exhibit · Scanning electron microscopy
A working scanning electron microscope. Every image, pattern and spectrum is computed from the physics of electrons hitting a solid. Click any label on the instrument for the physics behind it.
What you are looking at
About this exhibit
What is computed, and how
Images are formed pixel by pixel from multiscale specimen models (height, material, crystal orientation). SE yield follows the universal δ(E) curve and the secant law, with an edge effect scaled by the electron range and SE2 generated by backscattered electrons. BSE yield follows Reuter/Arnal η(Z, tilt), with channelling contrast from the local crystal orientation. The ETD includes shadowing and grid bias. The probe diameter is the quadrature sum of source image, Cₛ, Cc and diffraction; focus, astigmatism and depth of field blur the image. Charging appears for uncoated insulators above E2.
EBSD/TKD patterns are Kikuchi bands in gnomonic projection (width 2θB, strength from structure factors), mixed over the interaction footprint. They’re indexed with a real Hough transform and interplanar-angle voting, and compared with the true orientation. EDS uses Anderson–Hasler X-ray ranges, overvoltage, a simplified absorption correction and Kramers bremsstrahlung. Interaction volume is a single-scattering Monte Carlo (screened Rutherford, Joy–Luo stopping power).
Simplifications: pattern intensities are kinematic, matrix corrections are schematic, and the specimens are procedural. Trends, length scales and the metrology are right; absolute intensities are illustrative.