Speaker
Description
Controlled irradiation with synchrotron radiation requires precise knowledge of beam power and spatial intensity distribution. We present a comprehensive characterization of the PTB white light beamline DWL20 at BESSY II. The beamline utilizes direct radiation from a dipole bending magnet, focused by a Rh-coated ellipsoidal mirror and spectrally shaped using selectable filter configurations.
A calibrated CCD camera was employed to determine both the total beam power and the spatial beam profile at various distances from the focal point. The CCD was previously calibrated at the PTB EUV beamline, enabling a quantitative conversion of measured count rates into absolute power values. Measurements for different filter setups allow adjustment of the beam power.
The spatial analysis reveals a linear dependence of the beam width on the distance from the focus. Further, the beam structure shows a pronounced intensity peak and a broader homogeneous region. Based on this, the beam was systematically separated into a spot with high intensity and one with low intensity.
Combining total power measurements with spatial intensity distributions enables the determination of power densities for both regions as a function of focal position. The results provide a consistent and quantitative description of the DWL20 beam properties and form a reliable basis for reproducible irradiation experiments.