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Example X-ray fluorescence mapping datasets recorded at the Diffraction Endstation (EH2) [1] of the NanoMAX beamline [2] at the MAX IV Laboratory [3]. The samples were pollen of leucanthemum vulgare mounted on silicon nitride membranes. They are kept in the folder and file structure typical to the lab and beamline. The upload contains the raw data, the macros to record the raw data, the script used to fit the raw data, the fit results in various file formats and jupyter notebooks loading the fitted results to vizualize the elemental maps. The two maps are the results of an inhouse beamtime (proposal 20260002) and a practical for the HERCULES course (proposal 20261166) respectively. Data was recorded using a photon energy of 12.4 keV for the probing beam. A pair of KB-mirrors [4] was used to focus the X-ray beam to a size of 70nm x 70nm (full width at half maximum). The samples were positioned in the X-ray focus and laterally fly-scanned in grid pattern over a scan region of 42µm x 42µm / 30µm x 30µm with a step size of 70nm / 130nm respectively. Both times the total sacn regions was subdivided into multiple seperate scans. At each scan position a X-ray fluorescence spectrum was recorded with an silicon drift detector (SDD) (RaySpec, UK), a Xspress3 pulse processor (Quantum Detectors, UK) and an exposure time of 100 ms. The detector was positioned perpendicular to the probing beam in the direction of linear polarization of the X-ray beam. The sample was rotated such that the angle between the sample surface normal and the X-ray optical axis was 20 degrees and the angle ebtween the sample surface normal and the SDD was 70 degrees. X-ray fluorescence fitting of the recorded spectra was performed using the pyMCA-software [5]. No XRF standard was measured. This means, the presented results are qualitative, but not quantitative (fitted results are in arbitrary units and not nanograms per square millimeter) We acknowledge the MAX IV Laboratory for beamtime on the NanoMAX beamline under proposals 20260002 and 20261166. Research conducted at MAX IV, a Swedish national user facility, is supported by Vetenskapsrådet (Swedish Research Council, VR) under contract 2018-07152, Vinnova (Swedish Governmental Agency for Innovation Systems) under contract 2018-04969 and Formas under contract 2019-02496. References: [1] Dina Carbone et al., "Design and performance of a dedicated coherent X-ray scanning diffraction instrument at beamline NanoMAX of MAX IV", J. Synchrotron Rad. 29, 876-887 (2022). https://doi.org/10.1107/S1600577522001333[2] Ulf Johansson et al., "NanoMAX: the hard X-ray nanoprobe beamline at the MAX IV Laboratory", J. Synchrotron Rad. 28, 1935-1947 (2023). https://doi.org/10.1107/S1600577521008213 [3] Aymeric Robert et al., "MAX IV Laboratory". Eur. Phys. J. Plus 138, 495 (2023). https://doi.org/10.1140/epjp/s13360-023-04018-w [4] Maik Kahnt et al., "Complete alignment of a KB-mirror system guided by ptychography," Opt. Express 30, 42308-42322 (2022) https://doi.org/10.1364/OE.470591[5] V.A. Solé et al., "A multiplatform code for the analysis of energy-dispersive X-ray fluorescence spectra", Spectrochimica Acta Part B: Atomic Spectroscopy 62 (2007) 63-68. https://doi.org/10.1016/j.sab.2006.12.002[6] Alexander Björling et al., "Contrast - a lightweight Python framework for beamline orchestration and data acquisition", J. Synchrotron Rad. 28, 1253 - 1260 (2021). https://doi.org/10.1107/S1600577521005269 Data structure - raw data The raw data files written by the contrast control software [6] used at the NanoMAX beamline are written in the folder /<proposal>/<data_of_the_visit>/raw/<sample_name>/. Their name is the respective scan number zero-padded to 6 digits with the file ending '.h5'. The XRF detector is also writing a separate hdf5 file for each scan into the same folder. Its content is linked through to the main scan file. Within the main scan file (scan number zero-padded to 6 digits) the data fields of interest are: /entry/measurement/pseudo/x = The horizontal scan position of each scan point in micro meters /entry/measurement/pseudo/y = The vertical scan position of each scan point in micro meters /entry/measurement/xspress3/data = The list of the recorded spectra for each scan point. The pulse processor comes with inputs. The SDD is connected to the 3rd input (2, when counting 0,1,2,3). Each input is split into 4096 channels. Each channel roughly corresponds to 10eV. /entry/measurement/alba2/1 = The current on the ion chamber just upstream of the sample in Ampere used to normalize the measured data to the intensity of probing X-ray beam. Data structure - processed data The processing of the data happened for groups of consecutive (sub)-scans that mapped a larger area in small bits. It is saved within the folder /<proposal>/<data_of_the_visit>/process/<sample_name>/scans_<from>_to_<to>/. Within that folder the file with the fitted elemental maps is called fitted_elemental_maps.h5. Within it the map for each fitted XRF emission line can be found under: /fitted_elemental_maps/xrf_fit/results/massfraction/<element_and_emission_line> = The qualitative (in this example not quantitative) 2D elemental distribution of the element in question. The same maps are also saved separatly as .tif files in the subfoler /IMAGES/. The naming of the tif files with the mass fractions follows the naming scheme: fitted_elemental_maps_w<element_and_emission_line>.tif.