抄録
X-ray fluorescencø spectroscopic analysis with a radioactive β-ray source is applied for analyz-ing binary alloys and measuring thickness of thin coating. β-rays from constituent elements by irradiation of n-rays from 90Sr-90Y (10mc) are discriminated by a filter or a pulse height analyzer. The detectors used are a proportional counter and a thin Nal scintillation counter, the resolving power of each of which is experimentally determined. β-rays scattered by the specimens are deflected off by an electromagnet provided in front of the counters.
The results obtained are as follows.
(1) From analysis of copper-zinc alloys carried out with a nickel filter of 12-36 microns thick, a calibration curve of almost linear form was obtained which gives measuring accuracy of 2% in error.
(2) Tin-copper alloys were analyzed by the use of a pulse height analyzer coupled with a pro-portional counter. The accuracy obtained was 0.5% in error for specimens containing over 80% of copper.
(3) Coating thickness of less than 10 microns of chromium or cadmium on copper was deter-mined by the same method as used in (2) with fair accuracy. For chromium coating of less than 4 microns, Cu KX-ray measurement gave an accuracy of 0.1 micron.
