BL  3W1A  Biologic Macromolecule Crystallography Station

 

Beamline 3W1A is upgraded to a monochromatic one for protein crystallography (PX) during 2001-2002. The PX end station start in operation from the end of 2002. The beamline provides a wavelength-tunable and focusing X-ray for PX experiments, especially for MAD.

 

Research fields

Structure determination of biological macromolecules;

Methodological research in structure determination of protein;

 

Beamline parameters

Energy range: 6-16 keV

Energy resolution: better than 4X10-4

Flux at sample: better than 5X1010 photons/s

Spot size: 0.8(H) X 0.6(V) mm2

Divergences: 5(H) X 0.5(V) mrad2

 

End station

1.      Detectors

Mar345 Imaging Plate

Active imaging surface: 345 mm diameter

Pixel sizes: 100mm or 150mm (selected by the software)

Dynamic Range: 1: 128000

Readout speed: 108 sec. @345mm, 100mm

MarCCD 165mm

Active imaging surface: 165 mm diameter

Pixel sizes: 80mm(@2048X2048); 160mm(@1024X1024); 320mm(@512X512)

DQE (Detective Quantum Efficiency): DQE up to 0.8 for 8 keV-12keV

PSF (Point Spread Function):       FWHM  ~ 100µm

                         FW 1%M ~ 300µm

Dynamic Range (~ Full Well / Noise): 16 bits

Readout speed: 3.5 sec. @2048X2048

2.      Marresearch Desktop Beamline

General

·        Automatic alignment via remote control or host computer

Collimator System

·        Motorized Slits

·        Automatic beam shape optimization

·        Variable aperture from 0 to 5 mm with 2.5 µm resolution

·        Ionization chamber with 108 dynamic range

·        Fast (1ms) rotary beam shutter

·        High resolution CCD Camera (0.0003 lux / f1.4) with a 2 mm x 2 mm viewing area for easy crystal location and centering

·        4” LCD monitor integrated in goniometer (50:1 magnification)

·        Motorized precision tungsten primary beamstop with automatic beamstop-to-crystal-distance optimization

(50 mm maximum crystal to beamstop for low resolution optimization)

Goniometer System

·        High precision motor driven phi-axis with horizontal configuration

·        Resolution: 0.000625°/step, speed: up to 900°/minute

·        Accuracy: 0.002°, reproducibility: 0.00125°

·        Manual gearlock (anti-clockwise) for easy crystal centering

·        Electronic referencing of zero position

Detector Mount

·        Motorized vertical 2-theta arm (0° to 30°)

2-thetamax = 96°, dmin (MoKα) = 0.48 Ǻ, dmin (CuKα) = 1.04 Ǻ

·        Motorized crystal to detector distance translation stage

75 mm to 425 mm

·        Resolution: 1.25µm/step, speed: up to 25 mm/second

Cardanic Cradle

·        High precision vertical and horizontal translation

·        Vertical range: ± 7.5 mm (352.5 mm to 367.5 mm above table top)

·        Vertical resolution: < 1 µm (0.05µm/step), vertical speed: 0.2 mm/second

·        Horizontal range: ± 10 mm

·        Horizontal resolution: < 1 µm (0.3125 µm/step), horizontal speed: 3 mm/second

·        Vertical rotation range: @ 2°

·        Vertical resolution: @ 0.3 µrad/step, vertical speed: 2mrad/second

·        Horizontal rotation range: ± 3.5°

·        Horizontal resolution: @ 0.8 µrad/step, horizontal speed: 15mrad/second

·        Configurable adaptive beam optimisation: any beam from any optic

Cryogenic Accessories

·        Cryostream mount at 45° about the beam axis (5° towards the source, no distance restrictions)

·        Cryostream exhaust with an adjustable flow rate, up to 50 l/minute capacity and virtually no icing near the sample

3.      Sample cooling

Oxford Cryosystems Cryostream Cooler, 700 Series

AD41 Dry Air Unit

4.      Energy scanning system for MAD

NaI scintillator is used for detecting the fluorescence from crystal sample. The system is controlled by a LabView-based program.

5.      Experiment controlling and data acquisition systems

A LabView-based software provides the necessary controlling of beamline. Data acquisition is performed by software provided by Marresearch/MarUSA.