A normal-incidence beam line at the MAX storage ring

Abstract

A 1-m normal-incidence monochromator has been designed and installed on a bending-magnet beam line at the MAX storage ring in Lund. The optical properties of the beam line have been investigated via ray-tracing studies and with flux measurements of the beam line-monochromator combination. A resolution of 0.9 Å at 919.8 Å was measured in first-order diffraction with an argon hollow-cathode lamp for slit openings of 100 μm. A photon flux of 2.0 × 1010 at 550 Å with 250 μm slits was measured with a calibrated GaAs photodiode through a 1.5-mm diameter aperture in an aluminum mask on the photodiode. The new instrument has a microcomputer controlled mechanism which optimizes focussing requirements for a scanning monochromator with the requirement of fixed slits and fixed exit beam.