Optical performance of the Naval Research Laboratory's Materials Analysis Beam Line at the NSLS

The optical performance of the Naval Research Laboratory's Materials Analysis Beam Line at the National Synchrotron Light Source is reported. Photon fluxes into the experimental hutch were measured over the energy range from 3 to 11 keV. Two sets of flux data were taken, one with no slits in the beam and the other with a 2.5 mm diameter slit which passed only the best focused portion of the beam. At 6 keV, a total flux in excess of 2 × 10⁹ photons/(s mA) of stored current was observed. The focal spot was mapped at several energies using a pinhole and a detector which were mounted on a two dimensional translation stage. At 6 keV the fwhm dimensions of the focal spot were 1.0 mm horizontally, and 3.0 mm vertically. The energy spread in the monochromatic beam was estimated by measuring the width of a narrow pre-edge feature of manganese in KMnO₄ at 6.5 keV. The spread was minimized by adjusting the curvature and incident angle of a collimating mirror upstream of the beam line's monochromator. At 6.5 keV an energy spread of 2.6 eV was observed. These measured quantities of flux, spot size and energy resolution are compared to their expected values [1,2] to give an overall view of the performance of the optics.