- Standard configuration for absorption-based and edge-enhanced radiography and tomography
- Standard Configuration for Elevated Temperature In Situ Tomographic Microscopy
- Standard Configuration for Differential Phase Contrast (DPC) Imaging
- Automated Sample Exchange System
- Standard Configuration for Nanotomography
Standard configuration for absorption-based and edge-enhanced radiography and tomographyThe TOMCAT endstation for tomographic microscopy allows translation along the three spatial directions with a resolution better than 1μm. The axis perpendicular to the beam direction has a reproducibility of 0.1μm; this is imperative for an artifact-free acquisition of reference images. The sample can also be centered within 0.1μm reproducibility.
The rotation axis is a custom-modified, aerotech air-bearing-based system (link) and has a run-time error of less then 1μm at 100 mm from the rotation surface. It rotates with speeds up to 10Hz (1800deg/s). The whole sample manipulator can be rotated by 90°, allowing thick and short samples (vertical rotation axis) or long and thin samples (horizontal rotation axis) to be scanned. Please contact the beamline staff if you require a non-standard configuration for your experiments.
Additional details on sample mounting and sample environment can be found here.
Standard Configuration for Elevated Temperature In Situ Tomographic MicroscopyUSERS THAT WANT TO PERFORM EXPERIMENTS USING THE LASER SYSTEM MUST CONTACT THE BEAMLINE SCIENTIST RESPONSIBLE (J.L. FIFE, email@example.com) BEFORE THE PROPOSAL SUBMISSION DEADLINE.
The TOMCAT beamline offers a laser-based heating system for time-resolved in situ imaging. The system incorporates two 150W lasers at 980nm wavelength that are positioned approximately 180° apart. The lasers are manipulated by x, y, and z linear stages such that a user-specified position can be heated. The lasers are also capable of moving as the sample moves. Temperatures are measured with a pyrometer (non-contact infra-red (IR) temperature measuring device), (currently) limiting the accessible temperature range to 350-1800°C. Power to the lasers is dynamically controlled based on the temperature read-out from the pyrometer, and temperature profiles are determined based on user specifications. The current setup is capable of both near-isothermal and directional heating within this temperature range. The laser system is compatible with various beamline configurations and can be used in multiple imaging modalities. The user is responsible for providing sample holders and setups that are compatible with the layout of the laser system (beamline staff will assist with this process). J.L. Fife, M. Rappaz, M. Pistone, T. Celcer, G. Mikuljan, and M. Stampanoni. Development of a laser-based heating system for in-situ synchrotron-based x-ray tomograpic microscopy, J. Synch. Rad. 19, 352-358, (2012).
Standard Configuration for Differential Phase Contrast (DPC) ImagingUSERS THAT WANT TO PERFORM DPC SCANS MUST CONTACT THE BEAMLINE REPONSIBLE (A. PATERA, firstname.lastname@example.org) BEFORE PROPOSAL SUBMISSION DEADLINE.
The TOMCAT endstation offers phase contrast imaging based on grating interferometry (see T. Weitkamp, A. Diaz, C. David, F. Pfeiffer, M. Stampanoni, P. Cloetens, E. Ziegler X-ray phase imaging with a grating interferometer, Opt. Express 13, 6296-6304 (2005), pdf).
The plug-in for DPC imaging can be easily mounted on the standard setup at TOMCAT. The figure below shows the interferometer mounted on the beamline.
Automated Sample Exchange System
The TOMCAT beamline also offers a robot for sample exchange. The robot can hold 60 samples in a tray and supports measuring multiple regions of interest in each sample. The system has been tested on fossils, geological samples, bones, metals, cements, and various embedded samples. Once the experiment has been properly set up, the automation tools present can run the full experiment from sample exchange to reconstruction without user intervention. The longest experiment performed to date was 125 hours without intervention. (see Mader, K., Marone, F., Hintermuller, C., Mikuljan, G., Isenegger, A., Stampanoni, M., High-throughput full-automatic synchrotron-based tomographic microscopy. J. Synchrotron Rad. 18, (2011) PDF-file).
A picture of the TOMCAT beamline setup and the progression of a typical automated experiment
Standard Configuration for NanotomographyLinking micrometer and nanometer scales, the TOMCAT nanoscope was commissioned in 2009 . Based on Zernike phase contrast , this full-field microscope is composed of a condenser (a custom designed beamshaper ) producing a top-flat illumination in the focal plane . After the sample, the Fresnel Zone Plate (FZP), with a focal length chosen according to the energy, acts as an objective lens. To exploit phase contrast, phase dots are placed at the back-focal distance of the FZP to generate Zernike phase contrast. The detector, placed downstream about 10 m, records the magnified phase contrast image of the sample. The field-of-view is approximately 50 μm2.
Thanks to the latest improvements in optical design, specifically with regards to the beamshaper  and the Fresnel Zone Plate, as well as on the hardware of the setup itself to produce higher stability, we are now able to use the nanoscope from 8 keV to 20 keV with approximately 200 nm spatial resolution. The setup can be used in absorption or phase contrast mode for a wide range of applications, including biology, geology, materials science, and paleontology.
For further information, please see:
 Stampanoni M. et al. (2009). J. Phys.: Conf. Ser. 186, 012018. DOI:10.1088/1742-6596/186/1/012018
 Zernike F. (1934). Physica 1, 689. DOI: 10.1016/S0031-8914(34)80259-5
 Stampanoni M. et al. (2010). Physical Review B 81, 140105. DOI:10.1103/PhysRevB.81.140105
 Jefimovs K. et al. (2008). J. Synchrotron Radiation 15, 106. DOI: 10.1107/S0909049507047711
 Vartiainen I. et al. (2014). Opt. Lett. 39, 1601. DOI: 10.1364/OL.39.001601
Ultra-fast endstation information will be available soon.