LOW-PROFILE HIGH-EFFICIENCY MICROCHANNEL-PLATE DETECTOR SYSTEM FOR SCANNING ELECTRON-MICROSCOPY APPLICATIONS

A new design high-efficiency microchannel-plate detector and amplification system is described for use in the scanning electron microscope. This complete detector system consists of four basic units: (1) the microchannel-plate detector; (2) the video amplifier; (3) the high-voltage power supply; and (4) the control unit. The microchannel-plate detector system is efficient at both high and low accelerating voltages, and is capable of both secondary electron and backscattered electron detection modes. The size of the actual detector is approximately 3.5 mm in thickness and 25.4 mm in diameter. Thus, use of this detector system permits using almost all the sample chamber to accommodate large specimens with only the loss of the 3.5 mm of working distance. Another feature is that this system also employs a unique video amplifier where there are no active elements at high voltage. The microchannel-plate detector system enables the investigation of secondary electron induced contrast mechanisms and backscattered electron detection at extremely low accelerating voltages even those below 1.0 keV.