Double Crystal X-Ray Dilatometer Using Continuous Radiation

Abstract

A new type of dilatometer has been built to measure the strain induced in crystals, for example, by irradiation. The instrument uses high angle diffraction to obtain large lattice dispersion, and the parallel crystal configuration to achieve low wavelength dispersion. It is not necessary to know the wavelength of the x rays nor the order of diffraction and the measurement of strain is reduced to the measurement of an angle. Strains of 1×10⁻⁵ may be measured with error less than 5%. The paper discussed the theory, design, and accuracy of the instrument and presents typical experimental results.