The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high{resolution lead/scintillating{ bre calorimeter.The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out{of{time background events at the rst trigger level. It must be compact due to space restrictions.These requirements were ful lled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic bres embedded in a lead matrix. Its lead{to{ bre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter bres with a lead{to{ bre ratio of 3.4:1.The mechanical construction of the new calorimeter and its assembly in the H1 detector are described.
A commercial scanning force microscope (SFM) has been modified by the incorporation of three miniature laser interferometers, and new calibration methods have been applied so that requirements resulting from traceability of measurement results to metrological primary standards can be better fulfilled. The progress attainable in this way refers to the accurate positioning of the probe with respect to the points to be sampled on the surface. The paper gives a brief introduction to the SFM and the interferometers, the approach to three-dimensional calibration of the SFM, selected calibration results and the compensation of calibration errors by the control software of the SFM. The SFM is applied to the determination of the coating thickness of corresponding artefacts. These results are consistent with those achieved by interference optical microscopy.A commercial scanning force microscope (SFM), VERITEKT 3 [1], is used to determine the surface topography of microstructures (e.g. artefacts for the thickness of coatings [2], optical gratings [3] and microhardness indenters [4]). The measurement results must be traceable to metrological primary standards.In the past, we calibrated the SFM by reference to calibrated artefacts [2]. To further improve its accuracy, we have fitted in the SFM a laser-interferometric 3D measurement system consisting of three miniature laser interferometers [5].The impulses emitted by the interferometers during movements along the axes can be used to generate calibration points within the measurement range of the SFM. The interferometers offer the opportunity to determine the metrological performance of the SFM -the performance of the scanner unit in particular -more completely and more suitably than is possible with other approaches known to date.As regards traceability, we understand the SFM to be a kind of miniature three-coordinate measuring system. Independent of the strategy on which the calibration is based, we have as the final calibration result regression functions which * Corresponding author describe the spatially dependent non-linearity and the crosstalk in the direction of the axes, and, in addition, functions which reflect displacements of the specimen in the x-and ydirections due to Abbe errors.For all three axes, compensation functions or data sets derived from these have been implemented in the SFM's control software. The consequence of this compensation by software is that nearly perfect calibrated equidistant scales and orthogonal axes of movement are obtained. The SFM is then capable of performing dimensional measurements with uncertainties of only a few nanometers.The SFM, with the incorporated laser interferometers, calibration results referring to a kind of pre-calibration and further evaluations revealing the 3D nature of the performance of the SFM, is described in [6]. This paper covers: -a brief introduction to the SFM and the interferometers -the approach to 3D calibration of the SFM and selected calibration results -a comparison of the results of the calibration...
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