X-ray Optics

Synchrotron Capillary Optics

Comparison of Sigray’s X-ray mirror lens with KB mirrors

KB mirrors are commonly employed in beamlines in part because, unlike CRLs and zoneplates, they are achromatic to enable use with a wide range of x-ray energies. 

Compared to KB mirrors, Sigray’s axially symmetric (paraboloidal or ellipsoidal) x-ray mirror lens offers:

1. Higher Flux: >4X larger flux due to 2X larger numerical aperture (flux at the focus is proportional to the square of NA). The optic is not only a single-bounce x-ray capillary, but its axial symmetry captures a larger cross-section of the x-ray beam.

2. Stable and In-Line Focal Spot: The focal length of Sigray’s lens is substantially shorter (10-50 mm). This significantly reduces the problems of focal spot positional variation due to source or beamline vibration that limit KB mirror performance.

3. Flexibility in Technique Development and Future Upgrades: Due to the small and lightweight form factor, multiple paraboloidal mirror lenses can be used on a single beamline, each optimized for specific parameters or for different techniques. Development of beamlines using the Sigray mirror lens also provides an easy path for future upgrades for additional optics and functionality.   

4. Cost-Effective Beamline Development: For microfocus beamlines the source needs to be demagnified by a large factor. Since KB mirror pairs have large focal lengths (room must be provided for the downstream mirror), demagnification requires long, expensive beamlines. In comparison, the Sigray paraboloidal condensers enable the development of shorter, cost-effective, multi-functional microfocus beamlines.

5. Low Weight & Ease of Operation for Scanning: Straightforward alignment and low weight enable scanning of the optic, which is particularly important when the sample is difficult to move. 

Comparison chart between Sigray x-ray optics vs. common synchrotron optics

Example Specifications of Custom Optic

Sigray’s synchrotron optics are available with a wide range of specifications for different beamline applications. An example set of specifications are as follows:

• Type: Achromatic paraboloidal (or ellipsoidal)
• Spot Size: <0.25 to <10 um (dependent on working distance and energy)
• Reflecting Surface: Coated with Pt
• Energy Range: 100 eV to 60 keV
• Angular Range: ~3X the critical angle of glass
• Working Distance: 2 mm to 10 cm depending on the desired resolution and application
• Price: $20k and up, depending on specifications

Additional optional configurations may include complete assemblies coupled to elements such as monochromators. If you have a beamline design already in mind and require a proposal for an optic, please fill out an optics proposal request form here. 

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Laboratory X-ray Optics

Sigray offers x-ray optics for developing laboratory instrumentation (e.g., microXRF, microXRD, protein crystallography, and SAXS systems). Key attributes include:

• Twin paraboloidal, ellipsoidal, or Wolter-type
• All optics are achromatic (no chromatic aberrations)
• Collimating or focusing designs

Twin (Double) Paraboloidal Laboratory Optics

Sigray’s laboratory x-ray optics are designed for coupling to the newest generation of ultrabright micro and nanofocus x-ray sources. The inner surface profile of the optic is shaped with two mirrored paraboloids: one that collimates the x-ray source beam and a second optic that focuses the collimated beam onto a single spot. 

Advantages that the optics provide include:

• Intense flux at the sample, due to a combination of: small point spread function, high transmission efficiency of ~80%, and large numerical aperture of the optics
• Highest quality spot of any laboratory x-ray optic: microns-scale spot with minimal tails
• Pencil beam focusing with large working distance (up to 50 mm) for excellent depth-of-focus
• Achromatic to ensure all x-rays are concentrated onto the same single spot

The above advantages are major contributors to the performance seen in the Sigray AttoMap products that use Sigray’s double paraboloidal x-ray mirror lens.