This paper describes the beamline optics for deep-etch x-ray lithography. In order to obtain a higher reflectivity than that provided by a mirror with a monolayer coating at photon energies of 4 to 6 keV, multilayer mirrors with a constant and graded d-spacing were developed. At an energy of 6 keV, a measured reflectivity of more than 80 percent and a bandwidth of 1 keV were obtained for a mirror with a Ni/C multilayer coating and a constant d-spacing. Moreover, it was found that, for energies form 4 to 6 keV, a multilayer mirror with a graded d-spacing provided a higher reflectivity and a wider bandwidth than a mirror with a Pt monolayer coating. A multilayer reflection mirror is a promising component of beamline optics for use in microfabrication and the structural analysis of materials.
At the Hamburger Synchrotronstahlungslabor HASYLAB two mirror benders are under construction which are intended to reduce the vertical divergence of the incoming white photon beam on the monochromator. The design of these benders are based on successfully used types for monochromatic beams. The aim of the improved design is to reduce the vertical divergence of the beam even under server thermal load. Ray tracing calculations show that even at first generation machines as DORIS such mirror gives a benefit to the experimental conditions. Finally the realization of the benders for a bending magnet and a wiggler beamline with a contact cooled mirror are shown and described.
This paper gives an overview of the current performances of the ESRF multi-segmented piezoelectric bimorph mirrors. These devices effectively combine the possibility of varying dynamically the average spherical bending radius with the capability of acting locally on the reflecting surface shape. A first generation consisting of two prototypes was completely characterized in the ESRF metrology laboratory and the mirrors are installed and fully operational on the ID26 and ID32 beamlines since October 1997. Results obtained during the characterization and the commissioning of these devices are presented. A second generation prototype mirror has been designed, manufactured, tested in the ESRF meteorology laboratory, installed and commissioned at ID26 in 1998. This last mirror exhibits sub- (mu) rad residual slope error rms in its central portion, 1 angstrom rms averaged microroughness a d can routinely achieve a vertical beam size as small as 7 micrometers FWHM at a focal distance of almost 3 m.
We report a progress in the aspherization of precision of optical surface by deposition of graded-thickness films onto spherical substrate. As a deposition film, we examined single layer and multilayer film. Mo/Si multilayer had small stress and small surface roughness up to the total film thickness of 1 micrometers , and is suitable for the thin film to fabricate mirrors in the EUVL camera. We demonstrate an aspherical mirror fabrication using mask deposition technique. The result shows good agreement between the measured and desired thickness profiles.
The toroidal, silicon mirror on microdiffraction beamline 7.3.3 at the Advanced Light Source provides a 1:1 focus of the bend magnet source. The mirror is bent by two lead springs that are bolted to it through a pari of adhesive bonded end blocks. Because of the high loads that these adhesive joints must carry, three specific features of the bonds were tested: bondline geometry of the mating end blocks, surface preparation of the adherends, and strength of the adhesive. Bond strengths were evaluated by loading small test mirrors to failure using two epoxies under two different conditions of surface preparation - acid etching and simple UHV cleaning. In addition, the mirror's temperature distribution and figure errors were calculated with an Ansys Finite Element Model. The model's predictions were correlated to long trace profilometry as well as x-ray focus measurements.
The objective of this project is to develop a liquid-cooled window to transmit a high-energy laser beam. The window is to be used with continuous wave lasers with wavelengths between 1.0-1.4 micrometers and is to be 20 more centimeters in diameter. The window must transmit the beam with only small phase and amplitude distortions. The goal is less than 1/20 wave distortion across the beam at 1.315 micrometers that is the primary wavelength of interest. A prototype window will be built at a later data. In this paper results are presented of research into a) techniques for bonding two pieces of fused silica to from the window and b) suitable coolants.
A detailed thermal deformation and slope-error analysis is performed on an indirectly-cooled design of a high-heat-load vertical-focusing mirror.THe cooling of the mirror is through copper plates inserted into two grooves along the sides of the mirror. The contact between the mirror and the copper plate is through a gallium-indium eutectic bath in the groove. This configuration provides efficient thermal contact between the mirror substrate and the cooling block without applying stress to the mirror from the cooling block. This mirror will be used at the Advanced Photon Source Sector-15 ChemMatCARS undulator beamline for vertical focusing. It will be exposed to white beam with a heat load of about 1.1 kw.
Last year we presented a paper about a mechanical bender in which we manufacture a complete structure holding the mirror and the actuator. Although very accurate this system is very expensive, so we have developed a new generation of mechanical benders in which the mirror itself is used as part of the structure.
X-ray undulator beamlines at third-generation synchrotron facilities use either a monochromator or a mirror as the first optical element. In this paper, the thermal and optical performance of an optimally designed contact-cooled high-heat-load x-ray mirror used as the first optical element on the 2ID undulator beamline at the Advanced Photon Source is reported. It is shown that this simple and economical mirror design can comfortably handle the high heat load of undulator beamlines and provide good performance with long-term reliability and ease of operation. Availability and advantages of such mirrors can make the mirror-first approach to high-heat-load beamline design and attractive alternative to monochromator-first beamlines in many circumstances.
Non-intuitive surface scatter effects resulting from practical optical fabrication tolerances frequently dominate both diffraction effects and geometrical aberrations in high resolution grazing incidence x-ray synchrotron applications. The resulting reduction optical performance due to scattering is a strong function of x-ray energy, residual surface characteristics, incident angle, and the optical performance criterion appropriate to the application. A simple Fourier treatment of surface scatter phenomena, based upon a non-paraxial scalar diffraction theory, is referenced and utilized to produce parametric performance predictions that provide physical insight and understanding into the surface scatter phenomenon and its effect upon optical performance in x-ray synchrotron applications.
This paper describes metrology of a vertically focusing mirror on the bending magnet beamline in sector-1 of the Advanced Photon Source, Argonne National Laboratory. The mirror was evaluated using measurements from both an optical long trace profiler and x-rays. Slope error profiles obtained with the two methods were compared and were found to be in a good agreement. Further comparisons were made between x-ray measurements and results from the SHADOW ray-tracing code.
An in-situ long trace profiler developed at Brookhaven National Laboratory under the auspices of a CRADA with Continental Optical Corporation has successfully measured thermal distortion on a side-cooled mirror in a beam line at the Advanced Photon Source. The instrument scanned the central 90 mm of the 200 mm long mirror through a vacuum window while the mirror was subjected to heat loading from the synchrotron beam. Results clearly show transient effects occurring when the mirror is first illuminated that relax after about 15 minutes, in accord with finite element thermal calculations. The steady state curvature of the surface is measured to be slightly concave with an additional 5 km radius relative to the initial nominal curvature of about 1 km. The magnitude of this steady state condition was not expected and was not predicted by the calculations.