| 摘要 |
945,046. Measuring thickness using beta particles. COMMISSARIAT A L'ENERGIE ATOMIQUE. Sept. 8,1961 [Sept. 8, 1960], No. 32300/61. Heading G1A. Apparatus for measuring the thickness of metallic deposits, of the type wherein # particles from source 11 bombard a sample deposit 2 and the X-rays, characteristic of the metal tested, emitted by the sample are detected by proportional counter 10, and wherein the retrodiffused # particles from the sample are deviated from the counter by a magnetic field, is characterized by the provision of a direct connection between the sample and the proportional counter chamber, comprising a non-magnetic tube 8, passing the X-rays and subjected to the magnetic field by magnet 9. Irradiation chamber 3, tube 8 and counter chamber 10 are hermetically sealed by rings 7, 14, 15 and 16 and filled with an innert gas mixture 90% argon, 10% methane. To enable the sample deposit to be removed and changed the source holder 12 can slide down through chamber 10, by means of screw 17 and clamp 18 and hermetically seal the tube 8 and counter chamber 10 by means of the sealing ring 9, engaging a flange on the inner wall of the irradiation chamber 3. The Specification describes the variation in resistivity of the apparatus with the pressure of the enclosed gas. |
