S70PX system on MicroMax007HF with RAXISIV++ camera (click to enlarge)

APPLICATIONS

Demonstrated structure solution data from protein crystals down to 20µm diameter. Unmatched high structure-resolution data and rapid collection from larger crystals.

FEATURES

S70PX Optic: World's most intense microbeam for protein microcrystallography. Specifically designed for the new 0.07x0.7mm-target rotating-anode generators. Best signal-to-noise ratio available due to small beam diameter and minimum scatter path (as per synchrotron micro-PX configurations). Utilises high-efficiency single reflection ellipsoidal monocapillary optic in "confocal" geometry to re-image source at specimen position. Shortest optical path length of any available PX system minimises optical aberration and maximises flux interception over specimen diameter. White-radiation is excluded by optic and beam is unpolarised.

SRA Optical Stage: High-precision micrometer positioners for optic, integral rotary shutter mechanism and safety interlocks, adjustable Kb filtering from 0 to 20 µm. No-filter position allows rapid specimen quality survey and data collection from weak diffractors for which Kb intensity is negligible or readily resolved. X-Y adjustable "microbeamstop" for minimum exposed coldstream beam-path between exit collimator and beamstop (12mm). Stage replaces standard camera-shutter to permit maximum solid-angle collection from source and features helium beampath from coldstream up to generator high-vacuum window.

SPECIFICATIONS

  • Beam diameter at crystal: 100 µm FW

  • Beam divergence: 0.2° Full width above background

  • Monochromaticity: 97% Ka, <1% Kb (minimum filtering)

  • Cell-edge resolution: 400Å at 300 mm camera length

  • Beam focus position: at crystal, 200mm from anode target position

  • Intensity: 50x collimation [with filter present]

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    REQUIREMENTS

  • Rotating anode X-ray generator, Cu anode, 0.07 x 0.7mm target focus cup

  • Specimen oscillation stage with lateral translation (oscillation axis 200mm from anode target, at 6° take-off angle)

  • Specimen telescope with crosshairs/graticule

  • Helium feed for optics (optional for 15% added flux - optic does not tarnish)

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    Performance comparisons

    Relative intensities for the S70PX system fitted to either the MicroMax007® or FR-E®

    Optical system S70PX rel. I S70PX rel. SNR
    MSC "Blue" optics 6x 12x
    Osmic VariMax HF optics 3x 6x

    Notes: Intensity is flux per unit area at specimen position.

    "rel SNR" is beam intensity / background scatter at equivalent angles - [How is this defined?]

    Comparison with VariMaxHF configured for equivalent cell-edge resolution to S70PX

    "MicroMax" and "FR-E" are registered trademarks of Rigaku corp.

    VariMax is a trademark of Osmic inc.

    SRA-S70PX TECHNICAL DATA

    Clearances: Oscillation axis to beamstop positioner: 32mm; Depth of shutter unit below beam axis: 86mm

    Base plate: Form-factor of integral base plate is matched to specified make and model of X-ray generator. This ensures minimal optical alignment effort at installation.

    Shutter unit: High-speed longlife rotary solenoid. Optical shutter position interlocks. Replaces standard camera/rotary shutter fitted to anode tower. Connection to existing X-ray generator interlocks and shutter controller is supported by the unit.

    Alignment: Optical alignment upon installation is achieved by monitoring beam intensity at the specimen position (requires radiation meter) whilst adjusting optic position. Intensity max. corresponds with optimal alignment. Trim alignment (e.g. after anode assembly refit) is facilitated by fine adjustment verniers on X-Y adjusters.

    Exit collimator: The system is fitted with a fixed 0.1mm exit collimator which incorporates multiple lead and platinum apertures as scatter arrestors. Optic carrier is factory pre-aligned with exit collimator prior to shipment.

    Beamstop: 1.0mm diameter micro-beamstop is positioned just outside the coldstream to minimise X-ray scatter. The beamstop extension arm swivels to allow easy access to the goniometer head for specimen placement and removal.

    (c) copyright AXCO 2004

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