Slope errors of water cooling crystal surface for a double-crystal monochromator

For the third synchrotron radiation facility, four masons resulting in diffraction crystal distortion of double-crystal monochromator, and deficiency of traditional water cooling crystal are analyzed, and irregular structure of water cooling crystal is proposed. Slope error of crystal have achieved by numerical simulation analysis of finite element method. The result indicates that slope error of crystal surface in sagital and meridian is 1 and 0.6. (authors)