Detectors

Scintillators

Depending on user requirements (optimizing for speed or resolution), several scintillators are available. However, LAG:Ce scintillators are typically incorporated for a compromise in both speed and resolution, in the following configurations:
Scintillator Thickness (μm) Resolution Speed
LSO:Tb 5.9 Excellent (<1μm) Slow
LAG:Ce 20 Good (~1μm) Fast
LAG:Ce 100-150 Medium (>3μm) Faster
LAG:Ce 300 Poor (>10μm) Fastest
Please keep in mind that the thickness of the scintillator can affect your overall spatial resolution!

Other options are available. If you need a specialized setup, please contact beamline staff in advance of your experiments.

Detectors and Optics

The TOMCAT endstation features four microscopes that are compatible with four detectors. Depending on the detector/microscope combination, the field-of-view achieved can range from 0.4 x 0.3 mm2 to 16.6 x 14.0 mm2.

Three of the detectors are from pco and incorporate sCMOS and CMOS technology. The fourth is an in-house development, in collaboration with pco, that is currently being commissioned. The details are as follows:

pco.EDGE 5.5: sCMOS technology, 2560 x 2160 pixels, 6.5μm pixel size and a 16-bit nominal dynamic range → technical specifications

pco.EDGE 4.2: sCMOS technology, 2048 x 2048 pixels, 6.5μm pixel size and a 16-bit nominal dynamic range → technical specifications

pco.DIMAX: CMOS technology, 2016 x 2016 pixels, 11μm pixel size and a 12-bit nominal dynamic range → technical specifications

GigaFRoST: In-house development incorporating the same chip as the DIMAX but providing continuous acquisition at ~4-8GB/s → More specifications to follow.

The four microscopes have the following specifications:

Standard high resolution microscope: Optique Peter

The microscope system is based on diffraction-limited optics and can accommodate 1.25x, 2x, 4x, 10x, 20x and 40x objectives, see table below. The field-of-view and pixel size are calculated in the standard configuration, i.e., with the pco.EDGE 5.5 detector. If a different detector is used, these numbers will change.
Objective Magnification Numerical Aperture Field-of-view (mm2) Pixel Size (μm2)
PLAPO1.25x 1.25 0.06 13.3 x 11.2 5.2 x 5.2
PLAPO2x 2 0.08 8.3 x 7.0 3.25 x 3.25
UPLAPO4x 4 0.16 4.2 x 3.5 1.63 x 1.63
UPLAPO10x 10 0.40 1.7 x 1.4 0.65 x 0.65
UPLAPO20x 20 0.70 0.8 x 0.7 0.33 x 0.33
UPLAPO40x 40 0.90 0.4 x 0.3 0.16 x 0.16
Please remember that pixel size DOES NOT EQUAL spatial resolution! As a general rule-of-thumb, two pixels are necessary to define an edge and three pixels are necessary to define a feature. So depending on your goals, the spatial resolution can be 2-3 times the pixel size.

1:1 Optics: Optique Peter

The second system is based on a high-aperture tandem 1:1 configuration, accepting a diagonal up to 40 mm. It is typically used for the DPC setup or for large samples that do not require high spatial resolution. A larger pixel size option is available within this setup. Please contact the beamline staff if this option would benefit your experiments.
Lens Magnification Focal length Field-of-view (mm2) Pixel Size (μm2)
KinoOptik 1 150 mm 16.6 x 14.0 6.5 x 6.5
2-4x Continuous Magnification Microscope: Elya Solutions

The third system incorporates an optical microscope with continuously-adjustable magnification from 2 to 4 times, and it is designed for high numerical apertures and polychromatic radiation. This microscope is typically used with both the pco.EDGE 5.5 and the pco.DIMAX detectors in both monochromatic and polychromatic radiation. Therefore, the table below gives you the approximate range of pixel sizes and fields-of-view attainable within the limits of the magnification for the two different detectors.
Camera Magnification Field-of-view (mm2) Pixel Size (μm2)
pco.EDGE 5.5 2.1 7.9 x 6.7 3.1 x 3.1
pco.EDGE 5.5 3.9 4.4 x 3.7 1.7 x 1.7
pco.DIMAX 2.1 10.5 x 10.5 5.2 x 5.2
pco.DIMAX 3.9 5.6 x 5.6 2.8 x 2.8
High Resolution White-Beam Microscope: Optique Peter

The fourth microscope is a long working distance, high resolution microscope typically used with polychromatic radiation. It is based on diffraction-limited optics and incorporates two magnifications, 10x and 20x, and the specifications of field-of-view and pixel size are the same as in the table for the standard microscope (above).

Post-Processing and Reconstructions

All projections are post-processed online and reconstructions are available immediately after a scan is complete. Data can be exported as TIFF (8-bit or 16-bit) or in raw binary format (DMP format) on request. More details about the algorithms and reconstruction capabilities at TOMCAT can be found in:

F. Marone, and M. Stampanoni, "Regridding reconstruction algorithm for real time tomographic imaging", J. Synchrotron Rad., 19, 1029-1037 (2012). pdf