A variable-included-angle plane-grating-monochromator on an undulator for spectroscopy and microscopy at the Advanced Light Source

Abstract

A new beam line (beam line 11.0) at the Advanced Light Source has been designed to employ a Variable-Included-Angle Plane-Grating-Monochromator. The extended range available from a specific grating is exploited to cover energies from the carbon 1s absorption edge to the oxygen 1s absorption edge with two different gratings (150l/mm and 1200l/mm) with dispersion different by a factor of three. The phase space of a zone plate microscope can then be efficiently filled either at low or high resolution (R=2500 and R=7500).At the same time the monochromator is designed to cover the energy range from 75eV to 1500eV using the same two gratings at high resolution for spectroscopy. A deformable mirror pair will re-focus to a monochromatic spot 5 x 10 microns, matched into the acceptance of a fluorescence spectrometer.The monochromator will operate in vertically collimated light and the free choice of focussing parameter provides a guarantee of high resolution even when the power loading is high. However, we will provide a thermally engineered pre-mirror so that the high resolution requirement at low photon energy can be met without loss of efficiency.

Higher order harmonics suppression in extreme ultraviolet and soft x-ray

“…2. The optical scheme adopts the concept of the Variable Angle Plane Grating Monochromator, [21] and it benefits from wide spectrum, high resolution, and operation at variable C ff (focus constant) parameters. The source is a laser-produced Ar (or tin slab) plasma source.…”

New Implementation of an SX700 Undulator Beamline at the Advanced Light Source

“…In a beam line on a high power undulator the cooling of the optics becomes a challenge [4]. The new engineering employed in this facility provides optimized cooling, with water introduced through the monochromator scan-drive shafts, to minimize flexing bellows connections.…”

A variable fixed-focus constant optimization method for a variable-included-angle varied-line-spacing plane-grating monochromator

“…Besides covering a wide energy range, the VIA-PGM can also be operated in different modes depending on experimental need, such as a high-energyresolution mode, a higher-order harmonic suppression mode and a high-flux mode, by selecting a suitable value of the fixedfocus constant, C ff . Based on these advantages, VIA-PGMs have been employed on many synchrotron radiation beamlines all over the world (Xue et al, 2010;Aksela et al, 1994;Follath, 2001;Warwick et al, 2001;Follath et al, 1998).…”