Rapidly recorded X-ray diffraction powder patterns from some metals and from rock salt have been obtained by using the energy sensitive Si (Li) semiconductor detector with the multichannel pulse height analyser. The measured energy resolution of the detector system was about 210 eV for Cu KCY radiation. A good agreement was obtained between observed and calculated positions and relative intensities of the diffraction lines. 8 . H. Cole, J. Appl. Cryst. 3 , 4 0 5 (1970). Kynoch Press, Birmingham, England, 1962, p. 277. 98 X-Ray Spectrometry 1,1972