| 摘要 |
<p>1,076,589. Photo-electric analysis. PARAMETRICS Inc. Nov.23, 1965 [Nov. 23, 1964], No. 49822/65. Heading G1A. Analysis of a substance to determine its composition or the amount of a particular component is carried out by subjecting it toα-rays and investigating the characteristic X-rays produced thereby. The substance may be investigated by apparatus using backscatter or transmission geometry Figs. 1, 2 (not shown). The source, which may be Po 208 or 210, is arranged in a cup-shaped shielding container with a thin membrane of gold or platinum foil on top. The detector may be a scintillation counter or proportional counter, output of which is submitted to a pulse height analyser feeding a scaler. Counts are made in particular energy ranges, to include the energies of the characteristic X-rays of the different elements in the substance, (gas or solid). Alternatively a group of geiger counters, having different gas fillings, geometries or window materials, and thereby responding to different energy ranges, may be used. Instead of the radioactive source of alpha particles, helium nuclei from an accelerator may be used. The invention is designed to avoid continuous background radiation e.g. Bremsstrahlung being produced from the sample.</p> |
