Hitachi High-Technologies has introduced a new environmental secondary electron detector (ESED) for the S-3400N variable pressure scanning electron microscope
The new detector provides a powerful alternative to traditional backscattered imaging used in the VPSEM and closely mimics a conventional secondary electron detector to give good surface information.
The new ESED utilises the fact that secondary electrons produced from the sample surface by the primary beam can ionise gas molecules that are present in the chamber when operating in high pressure mode.
This results in the presence of positive and negative ions as well as electrons in the chamber.
The detector features an electrode which creates an avalanche effect from the ionisation process.
In a new, patented configuration, the ion current produced is collected with significantly improved signal-to-noise, producing images of outstanding quality.
The new detector has a rapid response and works well both at long and short working distance and low and high accelerating voltages.
Addition of the ESED allows simultaneous ESE and BSE imaging and EDX analysis.
Signal mixing allows surface detail from ESED to be combined with atomic number contrast from the BSD.