抄録
A preliminary study has been made of the effects of the thermal strain on the intensity of reflexion of X-rays transmitted through a crystal plate. The strain was produced in the plate by applying a temperature gradient along a certain direction, and the change of intensity was examined by the Laue photographic and the spectrometric methods. It was found that, in the cases of perfect crystals such as quartz, sodium chlorate and calcite, the contribution in reflexion of X-rays from the interior of crystal plate increased in a remarkable degree, while, in the case of an imperfect crystal, sulphur, the effects were very small. The general feature of the observed phenomena has been interpreted as due to the change of extinctions by the strain
