Abstract: Apparatus for displaying a visual image of the X-ray response of a specimen comprises an electron beam source for exciting X-ray emissions from the specimen. A detector detects X-ray photons emitted by the specimen and generates output signals representing the energies of X-ray photons received from discrete pixels of the specimen in a plurality of energy bands. A set of look-up tables generate for each pixel and for each energy band visual colour component signals related to the mean energy of X-ray photons emitted from the pixel and detected by the detector in that energy band. The range of X-ray energies is mapped into a range of visual colours. An accumulator combines the colour component signals for each pixel. The colour components for each pixel are stored in a frame store which is connected to a monitor which displays an image defined by the colour components.

Abstract: An Injector Junction Field Effect Transistor (IJFET) is disclosed which, in addition to having two gates (G1, G2) a drain (D) and a source (S), also has an injector (I). The device may be used as a high impedance charge or current amplifier in, for example, an x-ray fluorescence device. On applying current to the injector carriers are introduced into the channel of the device allowing a small gate leakage current to flow to restore charge to the input. A small restore current is therefore controllable by low impedance injector circuits.

Abstract: A technique for conditioning X-ray detectors which are introduced into electron microscopes and maintained at an operating temperature substantially below ambient is disclosed. Localized heating is applied to the detector by, for example, electrical resistance heating, whereby the detector is conditioned for about an hour without the heat sink being removed.