Adorym: A multi-platform generic x-ray image reconstruction framework based on automatic differentiation

We describe and demonstrate an optimization-based x-ray image reconstruction framework called Adorym. Our framework provides a generic forward model, allowing one code framework to be used for a wide range of imaging methods ranging from near-field holography to and fly-scan ptychographic tomography. By using automatic differentiation for optimization, Adorym has the flexibility to refine experimental parameters including probe positions, multiple hologram alignment, and object tilts. It is written with strong support for parallel processing, allowing large datasets to be processed on high-performance computing systems. We demonstrate its use on several experimental datasets to show improved image quality through parameter refinement

Synchrotron-based nu-XRF mapping and mu-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin

The increasing prevalence of tattoos provoked safety concerns with respect to particle distribution and effects inside the human body. We used skin and lymphatic tissues from human corpses to address local biokinetics by means of synchrotron X-ray fluorescence (XRF) techniques at both the micro (mu) and nano (nu) scale. Additional advanced mass spectrometry-based methodology enabled to demonstrate simultaneous transport of organic pigments, heavy metals and titanium dioxide from skin to regional lymph nodes. Among these compounds, organic pigments displayed the broadest size range with smallest species preferentially reaching the lymph nodes. Using synchrotron mu-FTIR analysis we were also able to detect ultrastructural changes of the tissue adjacent to tattoo particles through altered amide I alpha-helix to beta-sheet protein ratios and elevated lipid contents. Altogether we report strong evidence for both migration and long-term deposition of toxic elements and tattoo pigments as well as for conformational alterations of biomolecules that likely contribute to cutaneous inflammation and other adversities upon tattooing

X-ray scatter measurements from thermally slumped thin glass substrates for the HEFT hard x-ray telescopes

We have performed x-ray specular reflectivity and scattering measurements of thermally slumped glass substrates on x-ray diffractometers utilizing a rotating anode x-ray source at the Danish Space Research Institute (DSRI) and synchrotron radiation at the European Synchrotron Radiation Facility (ESRF) optics Bending Magnet beamline. In addition, we tested depth graded W/Si multilayer-coated slumped glass using x-ray specular reflectivity measurements at 8.048 keV and 28 keV and energy-dispersive measurements in the 20-50 keV rang at a double-axis diffractometer at the Orsted Laboratory, University of Copenhagen. The thermally slumped glass substrates will be used to fabricate the hard x-ray grazing incidence optics for the High-Energy Focusing Telescope. We compared the measurements to the SODART- mirrors from the SRG telescope mission program. The surface scatter measurement of the thermally slumped glass substrates yields Half Power Diameters (HPD's) of single- bounce mirrors of full-illuminated lengths of ~ 40 arcseconds for typical substrates and as low as ~ 10 arcseconds for the best substrates, whereas the SODART mirrors yields HPD's of ~ 80 arcseconds with very little variation. Both free-standing glass substrates and prototype mounted and multilayer-coated optics were tested. The result demonstrate that the surface scatter contribution, plus any contribution from the mounting procedure, to the Half Power Diameter from a telescope using the slumped glass optics will be in the subarcminute range.In addition we measured low surface microroughness, yielding high reflectivity, from the glass substrates, as well as from the depth graded W/Si multilayer-coated glass glass (interfacial width 4.2 Å)

X ray nanoprobe for fault attacks and circuit edits on 28-nm integrated circuits

International audienceIn various fields of application such as space devices, nuclear reactors, ionizingradiations can dramatically harm Integrated Circuits, and potentially break them.These effects are known for a long time, so forth understood at the physical level,and mitigated with various ways: specific cell designs, redundancy, etc. X rays arecommonly used to characterize ionization radiation faults and assess specificdesigns. However, X-rays - with a sufficient control on the impinging beam - canalso be used as a paramount tool to modify IC behavior at purpose. Thanks to a50-nm nanoprobe beam from the European Synchrotron Radiation Facility, wedemonstrate the modifications of single transistors to induce semi-permanentfaults, on a modern technology node: 28 nm. The set-up allows targeting anyspecific transistors and results show that n-mos (p-mos) single transistors can berespectively bypassed (blocked). Precise control the X-ray flux is easy such thatthe transistor can be perturbed for a short or longer duration. So far, many partsof an IC were modified at the single bit level: inverters, buffers, RAM, Flashmemories, which widens the range of applications of this controlled X-ray beam toboth circuit edits and fault attacks. This can be done without any invasive attackson the chips. Finally, perspectives to induce such effects with a cheaper and easilyavailable X-ray beam will be described

4D nano tomography for fundamental studies in solidification of Al based alloys

International audienc