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Observations of ultraviolet light is the key to understand high temperature processes in the universe like hot plasma, accretion processes or illuminated protoplanetary discs around UV sources. Furthermore these observation contribute to major cosmological questions, like the distribution of baryonic matter or the formation of the milky way, as pointed out by Gomez de Castro et al.1 Driven by the idea to participate in the Russian World Space Observatory we started to develop a position sensitive micro channel plate detector (MCP) for spectroscopy in the range of 160nm to 300 nm. Although we are not part of this project we still build a MCP detector prototype. In this paper we will present the general design of the detector and mainly focus on the aspect of our photocathode, while the electronics will be explained in more detail in the paper Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout" (Paper number 9144-116) by Marc Pfeifer.

The World Space Observatory Ultraviolet (WSO-UV) is a multinational mission under the leadership of Russia with contributions of Spain and Germany. The mission is part of the Spektrum series and launch is currently scheduled for 2016. It consists of a 1.7m mirror focusing on spectrographs in the range of 102-310 nm withh a resolution of R ≥ 55,000 for high resolution spectral observations, a long-slit-spectrograph for spatially resolved observations and an imager. According to the Phase-B-Study all spectrographs will use the same detectors built by the IAAT. These spectrographs are designed to observe cosmic plasma with temperatures of several ten thousands Kelvin and atomic transition lines of all important atoms and molecuules like H2, CO, OH eetc. In knowledge about the formation of galaxies and analyze the atmospheres of extrasolar planets and protoplanetary discs. To achieve these goals the IAAT designed in cooperation with the Leibniz-Institute for Analytical Sciences (ISAS Berlin) the spectrographs. In addition Tubingen develops and builds a new type of michrchannel plate detector based on gallim nitride cathods and a cross-strip-anode.

The spectrographs of WSO-UV cover the wavelength range of 102 - 310 nm. The essential requirements for the associated detectors are high quantum effciency, solar blindness, and single photon detection. To achieve this, we develop a microchannel plate detector in a sealed tube. We plan to use cesium activated gallium nitride as semitransparent photocathode, a stack of two microchannel plates and a cross strip anode with advanced readout electronics. Challenges are the degradation of the photocathode under atmospheric conditions and the sealing process. We present the detector concept, details of the transfer and sealing processes under UHV, and the current status.

The morphology and the free strain performances of three different piezoelectric ceramic fibers used for the manufacture of active fiber composites (AFCs) have been investigated. The morphology of the fibers has a direct influence on the manufacture of the AFCs. Fibers with non-uniform diameters are more difficult to contact with the interdigitated electrodes and can be the cause of irreparable damages in AFCs. An indirect method requiring the use of a simple analytical model is proposed to evaluate the free strain of active fiber composites. This indirect method presents a relatively good agreement with direct free strain measurements performed with strain gages glued on both sides of an AFC. The results show a systematic difference of ca. 20 % between the indirect and the direct methods. However, the indirect method did not permit to see differences of piezoelectric performance between the types of fibers.