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Für die Entwicklung einer neuen Generation von optischen Atomuhren mit noch geringeren Unsicherheiten in der Abteilung 4 wird eine Quelle von Th‑229 Atomen benötigt. Eine Möglichkeit Th‑229 Atome zu produzieren, ist diese als Rückstoßionen aus dem Alpha‑Zerfall des U‑233 zu gewinnen. Eine erste Analyse einer am Institut für Kernchemie der Johannes Gutenberg‑Universität Mainz hergestellten Quelle...

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Zur Darstellung und Weitergabe der Einheit Bq/m3 bzgl. Rn‑222 eignen sich für den niedrigen Aktivitätsbereich keine herkömmlichen Standards bestehend aus gasförmigem Rn‑222. Eine Alternative stellen Ra‑226 Quellen dar, die physikalisch-chemisch so beschaffen sind, dass das direkte Tochternuklid Rn‑222 zu einem gewissen Anteil aus der Quelle emaniert. Neue statistische Methoden auf der Basis der...

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Im Rahmen des traceRadon Projektes werden Radondetektoren entwickelt, die die Radonaktivitätskonzentration in der Außenluft rückführbar messen können. Dieses ist notwendig, um über die Radon Tracer Methode (RTM) eine Korrelation mit Treibhaus­gasen herstellen zu können (EMPIR 19ENV01 traceRadon). Dieses wird erreicht durch die Kombination der Quelle direkt mit einem alphaspektrometrischen...

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Im Rahmen der Digitalisierung in der Metrologie laufen Bestrebungen Methoden der künstlichen Intelligenz für die Spektrometrie zu nutzen. So werden z.B. Convolutional Neural Networks (CNN) zur Nuklididentifikation erprobt oder in Kombination mit Monte‑Carlo Simulation zur Entfaltung von Spektren verwendet.

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In June 2020 the EMPIR network project "Support for a European Metrology Network on Advanced Manufacturing" was started. This project targets at the strengthening of European manufacturing industry through innovative metrology. For the first time, a coordination at the European level will be realised, which enables an infrastructure for sharing of metrological knowledge. Moreover, a research...

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High-speed roughness measurements with piezoresistive silicon microprobes require good dynamic properties of the probe. For this purpose, tip flight tests were carried out with these microprobes on rectangular structures, in which the flight distance of the microprobe tips in the rectangular grooves was measured as a function of the probing force and the traverse speed. For the investigated...

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A novel 3D measuring method based on scanning electron microscopy and the "shape from shading" reconstruction approach was tested to characterize the shape of silicon-microprobe-tips. It could be shown that there is an optimal working distance, that tilting of up to 2 ° is tolerable, that the rotation of the sample is not critical for flat samples, but that there are edge deviations in the image...

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The eccentric nanoindentation of silicon micropillars has been investigated. It could be shown that 10 % deviation of the measured indentation modulus occurs when the location of indentation is deviating by up to 40 % of the radius of the pillar from the pillar’s centre. During these measurements the measured indentation hardness remains almost constant, while the measured indentation modulus...

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The novel picoindenter from PTB, which uses the tip of an atomic force microscope (AFM) as an indenter to characterize nanomaterials dimensionally and mechanically, has now been decisively extended: In the "Laboratory for Emerging Nanometrology" (LENA) at TU-BS, pyramid-like Berkovich tips were produced on AFM cantilevers using a focused ion beam (FIB). These tips can also be used in the...

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Sinusoidal chirp standards with surface wavelengths from 3.2 µm to 12 µm with three different amplitudes (0,4 µm, 0,7 µm, 1 µm) have been used to determine the topographic spatial resolution of optical microscopes applied for the measurement of structures with different aspect ratios. First results measured by an optical microscope operated in white light interference mode and confocal mode...

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Areal roughness measurements particularly with optical techniques play an increasing role for many applications in industry. This poses the question how factors influencing the roughness measurement can be identified reliably. To tackle this issue, the properties especially of confocal microscopy are systematically investigated by comparison to the spatially higher resolving atomic force...

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Within the framework of the EURAMET project 1242 ‘Measurement of areal roughness by optical microscopes’, coordinated by PTB, comparative measurements of areal roughness with different optical microscopes were carried out for the first time at 6 national metrology institutes. The comparison results revealed a large deviation up to 60 % from the reference roughness parameters, depending on the...

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A novel type of material measure for characterising two-dimensional (2D) instrument transfer functions (ITF) of optical areal surface topography measuring instruments has been developed. After being calibrated by the metrological large range atomic force microscope of PTB, the calibrated material measure has been successfully applied both in research and industry, showing its advantages like...

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In a novel approach, instead of a single, high-resolution measurement image, which is strongly influenced by drift, multiple low-resolution measurement images are recorded. These show less drift distortions each and can be used to reconstruct the temporal course of the drift. The low-resolution measurement images can be corrected using the reconstructed drift and combined to a high-resolution,...

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After the failure of a central electronic component of the measurement data acquisition of the primary angle comparator WMT 220, a complete renovation of the control and data acquisition of the angle table was carried out with substantial support from the company Dr. Johannes Heidenhain GmbH. In this context, the software for controlling the drives and reading out the new counter and phase...

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By means of Monte Carlo simulation of image formation in the electron microscope, the research group is able to generate large training data sets of high quality, which are of central importance for machine learning. On this basis, machine learning is being used within the framework of two European projects for the detection of particles and for the morphological characterization of soot,...

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State of the art three-dimensional atomic force microscopes (3D-AFM) cannot measure three spatial directions independently from each other. The 3D-Nanoprobe, a novel design based on a structured cantilever, is optimized to separate them. The detection method is based on two optical levers or one optical lever and an interferometer.

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As part of a project with industrial cooperation a measurement standard for the traceability of roughness measurements on involute gear flanks is developed. Algorithms enable the extraction of the deviations of the curved profiles and the calculation of the common roughness parameters. The software is applicable to both data from profilometers and coordinate measuring machines.

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