31 Aug 2023
Compound refractive lenses (CRLs) are widely used at synchrotron radiation facilities for X-ray beam shaping and focusing. They are mainly made by pressing a parabolic lens profile into a thin foil of aluminum or beryllium via a coining process. Their focusing capability depends on the manufacturing quality of the stamp and mechanical alignment during the coining process, both of which are limited by today’s technology. Recently, diamond CRLs made by laser ablation and mechanical polishing emerged, which exhibit similar shape errors. It has been shown that each lens shows a typical shape deviation of 500 nm from an ideal paraboloid of rotation. When many of these lenses are stacked in order to create submicrometer X-ray beams, these shape errors add up and lead to spherical aberration, impacting the resolution and imaging capabilities of X-ray microscopes. A solution to overcome these challenges is the correction of aberration by an additional optical element, called a refractive phase plate. It is tailor-made for the specific lens configuration and needs to be aligned with respect to the optical axis to within a few micrometers, requiring a motorization within a plane perpendicular to the optical axis. Here, we present the further development of the lens unit with integrated phase plate kinematic and the application at a high x-ray energy of 32 keV in a user experiment at beamline P06 at DESY. The performance of the focusing unit was evaluated at-wavelength in the high-coherence mode with ptychography and in the high-flux mode with a fluorescence knife-edge. Both methods are available to users at the beamline.20 Jul 2023
The working package WP15 of NFFA-Europe PILOT on Correlative Nano-Spectroscopy and Nano-Diffraction - Joint Action 5 (JA5) - aims to establish a user platform for routine experiments at Nanolabs and analytical large-scale facilities (ALSFs) permitting to collect structural and chemical information from a statistically relevant number of distinct nanoscale objects. Importantly, one prerequisite for an optimal determination of one-to-one size-structure-property correlations is that the probes like e.g., electrons or X-rays are illuminating individual nanoparticles. For experiments with a focused X-ray beam the foot-print is typically in the range of a few 10 nm × 10 nm up to a few 10 μm × 10 μm depending on the setup and the angle of incidence on the sample surface. Isolation of the nano-objects is required to ensure that signals are collected from only single nanoparticles. According to this prerequisite, the design and the creation of the proper templates for this type of experiments and the careful selection of protocols for the individual nanocrystal arrangement on the templates are essential (Task 15.2). The purpose of the deliverable D15.3 which is a part of the Task 15.2 is to summarize the different protocols for the fabrication of the templates and those of the individual arrangement of the nanocrystals on them by their colloidal dispersions. Optimization of the templates and arrangement protocols is included in this report ensuring a successful correlative experiment.28 Feb 2023
According to the Grant Agreement, in the lifetime of NFFA-Europe Pilot the Transnational Access offer must enlarge to meet (i) the qualitative needs of users that could be better met with new specialized providers, or (ii) quantitative needs resulting in oversubscription of the current capacity. To this aim, two calls for additional access providers were foreseen at M24 and M40, respectively. This report describes the rationale that led to the text of the first call for additional access providers, i.e. from the evaluation of the needs – mainly based on the analysis provided in the deliverable D2.3 “First balance of access provision” - to the search for alternative solutions to widen and strengthen the current offer.
