Quantitative X ray dark field and phase tomography using single directional speckle scanning technique
X ray dark field contrast tomography can provide important supplementary information inside a sample to the conventional absorption tomography. Recently, the X ray speckle based technique has been proposed to provide qualitative two dimensional dark field imaging with a simple experimental arrangement. In this letter, we deduce a relationship between the second moment of scattering angle distribution and cross correlation degradation of speckle and establish a quantitative basis of X ray dark field tomography using single directional speckle scanning technique. In addition, the phase contrast images can be simultaneously retrieved permitting tomographic reconstruction, which yields enhanced contrast in weakly absorbing materials. Such complementary tomography technique can allow systematic investigation of complex samples containing both soft and hard materials.