Lenses

 

 

With the advent of compound refractive lenses (CRL) for focusing purposes, the idea of collimating lenses was also discussed. For better matching the beam divergence to the acceptance of the first crystal of the HRM, collimating CRLs have been installed down-stream of the high heat-load monochromator. At 14.4 keV, e.g., the intrinsic divergence of the x-ray beam of about 14 urad has been decreased to 1.7 urad (see Figure).

 

Vertical angular profile of the x-ray beam upstream (solid circles) and downstream (open circles) of the compound refractive lens collimator. The width of the instrumental function of the utilized diffractometer is 2.0 urad. Thus, the angular with of the collimated beam is about 1.7 urad.