Analysis of Very Thin Organic Fibres by Means of Small Spots Electron Spectroscopy for Chemical Analysis

Abstract

Fig. 1 displays a schematic diagram of the small spot ESCA system SSX100. This instrument has the special capability for obtaining spectra from areas as small as 150 µm, which is used in this experiment. The system itself is very handy, nevertheless it can accomodate simultaneously 6 specimen each 173 mm diameter, or, alternatively, more than 500 samples of standard dimensions (10 mm diameter), or, if required, extremely small samples with typically few micrometer diameter. In the instrument an electron beam of 50–250 W is focused on an aluminium anode. The X-rays impinging on a 40 mm monochromatizing crystal 19 cm away are 40% reflected and focussed on the specimen surface in an area 0.15–1 mm diameter. The smaller diameter requires the lower beam power. The photon flux on the sample is about 10⁹ photons per square millimeter per second. The electrons which emit from the entire irradiated area in a 30° cone are taken by a lens system to the analyzer and detected by a multi-channel detector. The exact location of the sample area analyzed is established by viewing the analysis area through a microscope mounted over the specimen, and adjustment is made by micrometer screws with three degrees of freedom. Charging of insulators is compensated by a flood gun.