NanoMAX Experimental Stations
NanoMAX is a Hard X-ray (7–30 keV) monochromatic (with a crystal Si (111) based horizontal monochromator) nanoprobe experimental station at MAX IV. At the end of the commission phase of the project in 2018, NanoMAX is planned have two experimental stations: one station based on a diffraction limited Kirkpatrick-Baez (KB) mirror focusing system and a second station based on the use of Fresnel Zone Plates (FZP) as focusing optical elements. Both stations will provide nanoprobes with foci (plural focus x-y) in the 10-200 nm range. The two experimental stations are:
Experimental station for coherent X-ray diffraction imaging – CXDI
The KB-optics station started operation in May 2017. The Station is designed to focus the X-rays between 200-50 nm in the full photon energy range, the ptychographic reconstruction of the KB-mirrors focus at 8 and 14 keV have shown focus sizes of 98 and 62 nm, respectively). With a free distance of 100 mm between optics and sample versatile sample, environments can be accommodated. A two axes goniometer is used for flexible sample orientation (Figure 1). Sample environments will be developed by user groups or in collaboration with user groups (Figure 2).
Figure 1.- KB-mirror end station and sample environment, showing the two rotations available, two optical microscopes are located near the sample environment to have the precise location of the sample both in the horizontal and vertical plane. In between the sample position and the KB chamber, it is located a set of pinholes of different diameters and shapes.
Figure 2.- Sample enviroment, the sample holder is located on top of 3 piezo stages (x, y and z) of 100 μm range each that allow fine scaning of the sample, these piezo stages are located at the same time in 3 conventional stages (x, y and z) for longer moves around the sampl. Also shown in the left of the image the fluorescence detector AMPTEK Si‐Dri coupled with XSPRESS3.
The techniques offered in this experimental stations are:
- Bragg Ptychography, Bragg Diffraction and Bragg CDI: An articulated robot with a small pixel detector (512×512 pixels, 55 μm/pixel) is used for off-axis Bragg measurements (Figure 3).
- Forward Ptychography, Laue Diffraction and CDI: A megapixel detector placed in forward direction will provide scattering methods (At the moment, while the final detector is being purchased, it is possible to choose between a Pilatus 1 M, Pilatus 100 k or an Eiger 1 M, which is still under commissioning, Figure 3).
- X-ray Fluorescence: A 3-element Germanium detector will be used (at the moment an AMPTEK Si‐Dri coupled with XSPRESS3 is available for user experiments, Figure 2).
- An X-ray microscope based on a small pixel size camera together with a crystal scintillator will also be used in forward direction for various purposes.
Figure 3.- Diffraction detectors available at NanoMAX. A Merlin Merlin Si Quad. 512 x 512 pixels2, 55 μm square pixels is located in a Robot arm (Orange) to allow all types of Bragg geometry experiments. Three detector can be located in the forward direction: Pilatus 1 M (981 x 1043 pixels2, 172 μm square pixels), Pilatus 100K (487 x 195 pixels2, 172 μm square pixels) or Eiger 1M (1030 x 1065 pixels2, 75 μm square pixels).
Experimental station for tomographic imaging
The other experimental station will use Fresnel Zone Plates (FZPs) to provide focus down to 10 nm in a mature state. Main detectors will be: A large pixel detector in forward direction for diffraction and coherent imaging methods. A multi-element Silicon Drift Diode X-ray fluorescence detector for elemental mapping. Scanning stages will include XYZ motions and rotation around the vertical axis for tomographic methods. The station will not allow much sample flexibility due to extreme demands on stability and limited sample space. It will be built to operate in air. It is planned to provide in-vacuum, cryogenic capabilities in the future. The station is currently under development and prototyping and we anticipate to do the first tests during 2018.