摘要 |
A method of detecting particles in with low atomic numbers (e.g. diamonds) in material including particles with atomic numbers which are substantially higher, includes the steps of: irradiating each particle with X- rays to produce a secondary X-ray spectrum for the particle; measuring the intensity of the secondary X-ray spectrum in a selected energy region and at a selected angle relatively to the X-rays incident on the particle; and identifying as low atomic number particles those particles having measures lying in a predetermined range of magnitudes. Apparatus for carrying out the method comprises means (e.g. an X-ray tube 10) to irradiate a specimen (14) with X-rays to produce a secondary X-ray spectrum for the particle, means (e.g. an X-ray detector 12) to measure the intensity of the secondary X-ray spectrum in a selected energy region and at a selected angle relatively to the X- rays incident on the particle, and means (e.g. air operated ejectors or mechanical flaps) to separate from the material those particles which have measures lying in a predetermined range of magnitudes. <IMAGE> |