The SUNY X21 beamline at NSLS: A multi-use port on a dedicated high brightness synchrotron radiation source

The State University of New York is developing a beamline on the X-ray ring at NSLS, Brookhaven. The beamline has one port operating, at present. It has monochromator/mirror optics. There are two tandem experimental hutches. The upstream hutch contains diffractometry and X-ray spectroscopy apparatus. The downstream hutch houses a small angle scattering bench. Crystallography, spectroscopy, diffraction and scattering techniques can thus be used with the synchrotron source. Optical design is discussed with reference to the possibilities and constraints of bending magnet ports at NSLS and the requirements of the varied experimental program. Measurements made so far indicate that NSLS is indeed a high brightness X-ray source. High resolution edge spectra have been obtained of the ''white line'' at the L III edge of Ho and of Cu metal without slits in the beamline and with the expected structure resolved. This infers that the vertical opening angle of the X-ray beam appears dominated by the intrinsic opening angle of radiation from each electron with no further spreading from crossfire in the electron beam. For this particular measure of brightness the ring is thus as bright as it can be. The beam has been focused with a 1:1 bent toroidal mirror to a 1.5 x 1.5 mm (fwhm) focal spot. The horizontal focus correlates well with NSLS design parameters. The vertical height is not minimised but provides a symmetric beam for crystallography experiments. Measurements indicate little loss of energy resolution on focusing. These results are believed to be the first direct evidence of the achievement of high brightness in a synchrotron radiation X-ray source. Later measurements on other beamlines confirmed some of our conclusions about the source brightness. To demonstrate beamline performance, examples of results in crystallography, diffraction and spectroscopy are given. (orig.)