Patent Number: 051329972
Section: claims

1. An X-ray spectroscopic analyzing apparatus which comprises: a source of X-rays;  a first analyzing crystal for diffracting the X-rays from the X-ray source;  a second analyzing crystal for diffracting the X-rays from the X-ray source and also for passing therethrough a diffracted X-ray component from the first analyzing crystal;  said first and second analyzing crystals being disposed so as to permit the diffracted X-ray components of different wavelengths to travel along a single path towards a sample to be analyzed;  a filtering means for cutting a portion of the X-rays which has a wavelength shorter than a predetermined wavelength, said filtering means being disposed on an optical path extending between the X-ray source and the sample. 2. The X-ray spectroscopic analyzing apparatus as claimed in claim 1, further comprising a shutter means for selectively causing one of the diffracted X-ray components to be incident upon the sample to be analyzed. 3. The X-ray spectroscopic analyzing apparatus as claimed in claim 1, wherein one of the first and second analyzing crystal is operable to diffract a first-order X-ray beam coming from a target material of the X-ray source, and the other of the first and second analyzing crystal is operable to diffract X-rays which have a wavelength shorter than that of the first-order beam of X-ray. 4. The X-ray spectroscopic analyzing apparatus as claimed in claim 1, wherein said filtering means is disposed on an optical path extending between the X-ray source and the first and second analyzing crystals. 5. The X-ray spectroscopic analyzing apparatus as claimed in claim 1, wherein said filtering means includes a total reflection mirror having a first and second reflecting surface for effecting a total reflection of the X-rays which have been impinged thereupon at different angles of incidence. 6. The X-ray spectroscopic analyzing apparatus as claimed in claim 2, wherein said shutter means is disposed on an optical path extending between the X-ray source and the first and second analyzing crystals. 7. The X-ray spectroscopic analyzing apparatus as claimed in claim 2, wherein said filtering means is disposed on an optical path extending between the X-ray source and the first and second analyzing crystals and said shutter means is disposed on a portion of the optical path between the X-ray source and said filtering means. 8. The X-ray spectroscopic analyzing apparatus as claimed in claim 5, wherein one of the first and second reflecting surfaces of the total reflection mirror is operable to effect a total reflection of both of a first-order X-ray beam coming from a target material of the X-ray source and an X-ray component having a wavelength longer than the wavelength of the first-order beam of X-ray, and the other of the first and second reflecting surfaces of the total reflection mirror is operable to effect a total reflection of both of an X-ray beam having a wavelength shorter than the wavelength of the first-order beam of X-ray and an X-ray component having a wavelength longer than the wavelength of said X-ray beam. 9. The X-ray spectroscopic analyzing apparatus as claimed in claim 5, wherein said filtering means comprises the total reflection mirror and a beam stopper for shielding a portion of the X-ray component which has passed through the total reflection mirror, said total reflection mirror being comprised of a prism having the first and second reflecting surfaces opposite to each other, said first and second reflecting surfaces being so inclined as to converge in a direction confronting the X-ray source, and said beam stopper being disposed on a surface of the prism which lies on one side of the prism remote from the X-ray source.