Cryo SAXS sample environment Project update 02/2007

Transcription

1 Cryo SAXS sample environment Project update 02/2007 Manfred Roessle EMBL

2 Project Layout As proposed at kickoff meeting 12/ 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? Single particle scattering on forth generation X-ray sources?

3 Cryo - protectants for SAXS The formation of vitreous ice is a important condition for SAXS in cryo frozen samples. BSA standard (5mg/ml) in: 10% propanol Standard HEPES buffer 25% Ethylene glycol 30% propanol 50% Ethylene glycol Larger sample volumes cannot be flash frozen. Definition of SAXS useable cryo protectants such as propanol and ethylene glycol.

4 Cryogenic Sample Holder with y/z translation

5 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 (< mm) will be implemented 20 kg weight standard connectors

6 Cold finger cryostat

7 Cold finger cryostat

8 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 project submitted 01/2007)

9 Cryo SAXS sample holders 1.0 mm. 1.0 mm. 5.0 mm. Grenoble

10 Cryo SAXS sample holders 0.0? mm 0.? mm based on experience with models and Grenoble microfabricated collaboration with ESRF and ELETTRA Model TINY

11 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.

12 Automated Sample Changer

13 Automated Sample Changer

14 Automated Sample Changer

15 Automated Sample Changer Reliability tests 7. Stunde 4,500,000 4,000,000 3,500,000 3,000,000 2,500,000 2,000,000 1,500,000 1,000, , ,602,515 21,702,391 21,801,720 21,901,016 22,000,180 22,099,311 22,198,853 22,298,353 22,397,895 22,497,181 22,596,608 22,696,035 22,795,527 22,895,051 22,994,454 23,093,825 23,193,331 23,292,831 23,392,340 23,491,545 23,591,095 23,690,726 23,790,021 23,889,137 23,988,776 24,088,351 24,187,695 24,287,073 24,386,483 24,485,901 24,585,450 24,684,459 24,783,944 24,883,362 24,982,691 25,082,199 25,181,249 Spektrometerwerte

16 Detector System for cryo SAXS Pilatus Detector System: Key Features: High dynamic range: > 1: (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 = ~ pixels Active area single module: 33.5 x 84 mm 2 Counting rate: > 2 x 10 6 /s/pixel Framing rate: 30 Hz Energy range: 3 30 kev Installation 08/2007 at the SAXS beamline at EMBL

17 PILATUS Pixel Detector System 440 mm

18 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 pipeline

19 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