Finite-element analysis of thermal distortion of directly water-cooled silicon crystal monochromator

The directly water-cooled silicon crystal used on the multipole wiggler beam line BL16 at the Photon Factory has extended cooling fins below the crystal block. Such extended fins are useful to reduce bowing of the crystal due to thermal distortion induced by synchrotron radiation. Experimental and calculated Si(111) and Si(333) double crystal rocking curves are compared in the present paper. Thermal deformation is calculated using a finite element analysis program ANSYS. Fairly good agreement was obtained between experiment and calculation.