A RECORDING DETECTION SYSTEM FOR QUANTITATION OF ELECTRON MICROSCOPE IMAGE CONTRAST USING A RETRACTABLE MICRO-FARADAY CAGE PROBE

A recording electrometer system is described based on a retractable micro-Faraday cage probe mounted in the beam stop port of a Siemens Elmiskop IA electron microscope. A vibrating reed electrometer is used to measure the current collected by the probe. Intensity data at different points in the image are collected by moving the image over the fixed probe by manipulation of the specimen stage controls. The total system has a noise less than 3×10 -15 A, a 10 sec full scale response time, and provides immediately observable image intensity data which can be converted into contrast. © 1969 The American Institute of Physics.