The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

AAEM Projects

The Pi Steradian X-ray Detector
US. Patent # 8,314,386

Filed: Mar. 26, 2010, Issued: November 20, 2012

High collection efficiency X-ray spectrometer system with integrated electron beam stop, electron detector and X-ray detector for use on electron-optical beam lines and microscopes

In nano-materials research, one of the ubiquitous instruments we employ for characterization is the electron microscope. After electrons, the signal most often measured in these instruments is the emission of characteristic x-rays. During the last 40 years, either the solid state Si(Li) or more recently the SDD Energy Dispersive Spectrometer (EDS) 1,2 have been the detector most often used for this task. On one hand these detectors are remarkably, simple and efficient devices, but on the other there nearly always remains opportunities for improvement. X-ray spectrometer systems and methods are provided for implementing signal detection for use on electron-optical beam lines and microscopes. The X-ray Spectrometer System (XSS) includes an X-ray detector (XD) measuring the X-ray signal and positioned proximate to a specimen. An environmental isolation window together with an electron beam stop is disposed between XD and the specimen. The environmental isolation window and the electron beam stop protect XD from electrons directly transmitted through the specimen. An electron detector is located between the electron beam stop and the specimen allowing the measurement of scattered electrons. The XD measures an X-ray signal in the X-ray spectrometer system.