Cryo SAXS sample environment Project update 02/2007

(1)

Hamburg

Cryo SAXS sample environment

Project update 02/2007 Manfred Roessle

(2)

Hamburg

Project Layout

As proposed at kickoff meeting 12/2006…..

Three options and approaches:

1. Classical steady state SAXS on frozen samples

• Reduction of radiation damage

• Fixation of specimen for X-ray scanning experiments

• Downscaling of the sample volume

2. Time-resolved SAXS

• Stalling of reactions and measuring of the frozen sample

• Quenched freezing for medium time resolution (< 1sec)

• Microdroplets for mixing-on-the-fly (< 10ms)

3. Few particle scattering

• Single particle scattering on third generation X-ray sources?

(3)

Hamburg

Cryo - protectants for SAXS

BSA standard (5mg/ml) in: 10% propanol

Standard HEPES buffer

25% Ethylene glycol

30% propanol

50% Ethylene glycol

The formation of vitreous ice is a important condition for SAXS in cryo frozen samples.

Larger sample volumes cannot be flash frozen.

Definition of “SAXS useable” cryo protectants such as propanol and ethylene glycol.

(4)

EMBL

Hamburg

Cryogenic Sample Holder

(5)

EMBL

Hamburg

Cryogenic Sample Holder

with y/z translation

• ± 12.5 mm horizontal travel range • ± 50 mm vertical travel range

• Precision:

• 0.05 mm vertical • 0.01 mm horizontal

• Connectors for thermocouple • high precision absolute position

sensors (< 0.002 mm) will be implemented

• 20 kg weight

(6)

(7)

(8)

EMBL

Hamburg

Cryo – SAXS device mounted on

standard vacuum setup

• Adaptation of device in process • fast mounting for sample changing • positioning of sample with the y/z

translations

• development of a sample exchange protocol under liquid nitrogen

• Stand alone electronics and device control for easy exchange to other beamlines etc.

• design of a dedicated mounting setup suitable for e.g. ESRF (long term

(9)

Hamburg

Cryo – SAXS sample holders

1.0 mm.

5.0 mm.

1.0 mm.

(10)

Hamburg

Cryo – SAXS sample holders

Model “TINY”

0.? mm 0.0? mm

• based on experience with models “Hamburg” and “Grenoble”

• microfabricated

• collaboration with ESRF and ELETTRA

(11)

Hamburg

Automated Sample Changer

The sample changer will serve as basic platform for automated sample delivery to:

• increase the amount of analyzable datasets for the automated SAXS data

processing pipeline under “real” high throughput conditions

• standardize experimental procedures and conditions

• liberate user time for cryo-SAXS setup commissioning

It is planned to adapt the liquid handling device to other experimental equipment such as the cryo-SAXS sample holder.

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(13)

(14)

(15)

EMBL

Hamburg

Automated Sample Changer

Reliability tests

7. Stunde 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 4,000,000 4,500,000 ,6 0 2 ,51 5 ,7 0 2 ,39 1 ,8 0 1 ,72 0 ,9 0 1 ,01 6 ,0 0 0 ,18 0 ,0 9 9 ,31 1 ,1 9 8 ,85 3 ,2 9 8 ,35 3 ,3 9 7 ,89 5 ,4 9 7 ,18 1 ,5 9 6 ,60 8 ,6 9 6 ,03 5 ,7 9 5 ,52 7 ,8 9 5 ,05 1 ,9 9 4 ,45 4 ,0 9 3 ,82 5 ,1 9 3 ,33 1 ,2 9 2 ,83 1 ,3 9 2 ,34 0 ,4 9 1 ,54 5 ,5 9 1 ,09 5 ,6 9 0 ,72 6 ,7 9 0 ,02 1 ,8 8 9 ,13 7 ,9 8 8 ,77 6 ,0 8 8 ,35 1 ,1 8 7 ,69 5 ,2 8 7 ,07 3 ,3 8 6 ,48 3 ,4 8 5 ,90 1 ,5 8 5 ,45 0 ,6 8 4 ,45 9 ,7 8 3 ,94 4 ,8 8 3 ,36 2 ,9 8 2 ,69 1 ,0 8 2 ,19 9 ,1 8 1 ,24 9 S p ek tr o m et e rw e rt e 21

(16)

Hamburg

Detector System for cryo SAXS

Pilatus Detector System:

Key Features:

• High dynamic range: > 1:1 000 000 (20bits)/pixel/image • Very short readout time 3.4 ms

• No electronic noise

• Excellent point spread function: 1pixel

• Electronically gateable – No mechanical shutter needed Technical details:

• Pixel size: 172 x 172 µm

• Format single module: 195 x 487 = ~95 000 pixels

• Active area single module: 33.5 x 84 mm2

• Counting rate: > 2 x 106 _/s/pixel

• Framing rate: 30 Hz

(17)

Hamburg

PILATUS Pixel Detector System

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Hamburg

_{Further Work:}

• Testing of cryogenic frozen samples in the different sample holders • Design and installation of a quenched freezing device

(problem of vitreous ice formation and formation of ice grains)

• Construction of a dedicated mount for the use of the cryo-SAXS setup at other beamlines (e.g. ESRF, Elettra, Soleil)

• Adaptation of the automated sample changer at the EMBL SAXS beamline • High throughput recording of SAXS data for the automated data analysis

(19)

Hamburg

_{People involved:}

EMBL Team

Adam Round Postdoc Teemu Ikonen Postdoc

Dmitri Svergun Groupleader SAXS Roy Klaering Mechanics

Bernd Robrahn Electronics Fraunhofer Institute for Automation:

Roland Huchler Dirk Malthan Sandra Moritz