A High-Temperature X-ray Camera for use with Plate Specimens

The paper describes the construction of an X-ray camera suitable for use with plate specimens at temperatures up to about 1000 C. It is arranged that the specimen rotates in its own plane and is at the same time oscillated through small angles about a vertical in its surface. To surmount difficulties arising from the orientation of the crystals in the specimen it is also arranged that the X-ray beam falls on the surface of the specimen at various glancing angles during the exposure. These movements and adjustments are executed when the specimen, during irradiation, is maintained at high temperature in vacuo . The temperature of the specimen is measured either by measuring the parameter of a standard substance whose thermal coefficient of expansion is accurately known and which is exposed to the X-rays simultaneously and under the same conditions as the specimen under examination, or by calibrating the furnace with standard substances and employing the current through the furnace as an index of the temperature. The part of the apparatus, the camera proper, on which the X-ray film is mounted can be removed for the processing of the film and replaced again after reloading without disturbing the rest of the apparatus. Samples of structure-spectra taken with a double specimen, aluminium and silver, at different temperatures are given.