The effect of temperature on the average atomic absorption coefficients for x-rays.—The variation with temperature of the absorption by sheets of Al, Cu, Fe, Ni, Ag, and Pb of the total x-radiation from a tungsten x-ray tube operated at 50 kv has been studied. The measurements were made by balancing the ionization currents produced by two x-ray beams from the same tube, one of which passed through the absorber. After proper corrections are made for changes in the density of the absorber and of the air in the path of the beam, there remains a residual effect indicating a true variation of the atomic absorption coefficient with temperature. The results indicate that for all absorbers used the average atomic absorption coefficients for the total x-radiation from the tungsten target increased nearly linearly with the temperature by about 0.2 percent per 100°C up to temperatures near the melting point of the absorber. The work is being continued to determine the magnitude of the effect at different wave-lengths.

• Received 1 February 1924

DOI:https://doi.org/10.1103/PhysRev.27.373