The New X-Ray Mapping: X-Ray Spectrum Imaging Above 100 kHz Output Count Rate With the Silicon Drift Detector

Published

October 16, 2008

Author(s)

Dale E. Newbury

Abstract

Electron-excited x-ray mapping is a key operational mode of the scanning electron microscope (SEM) equipped with energy dispersive x-ray spectrometry (EDS). The popularity of x-ray mapping persists despite the significant time penalty due to the relatively low output count rates, typically less than 25 kHz, that can be processed with the conventional EDS. The silicon drift detector (SDD) uses the same measurement physics, but modifications to the detector structure permit operation at a factor of 5 to 10 times higher than conventional EDS for the same resolution. Output count rates as high as 500 kHz can be achieved with 217 eV energy resolution (at MnKa). Such extraordinarily high count rates make possible x-ray mapping through the method of x-ray spectrum imaging, in which a complete spectrum is captured at each pixel of the scan. Useful compositional data can be captured in less than 200 seconds with a pixel density of 160x120. Applications to alloy and rock microstructures, ultrapure materials with rare inclusions, and aggregate particles with complex chemistry illustrate new approaches to characterization made practical by high speed x-ray mapping with the SDD.

Citation

Microscopy and Microanalysis

Pub Type

Journals

Keywords

electron beam microanalysis, energy dispersive x-ray spectrometry, microstructural characterization, particle analysis, scanning electron microscopy, silicon drift detector

Citation

Newbury, D. (2008), The New X-Ray Mapping: X-Ray Spectrum Imaging Above 100 kHz Output Count Rate With the Silicon Drift Detector, Microscopy and Microanalysis (Accessed October 8, 2024)