The German R + D program "Solares Testzentrum Almeria" (SOTA) provided the scientific basis for the realization of advanced solar technologies including facility modifications, component tests and new lines of development. One of the working packages, WP 300, addressed the "Scientific Support" by the performance of preparatory studies, exploratory laboratory activities and qualified expertise. Universities, Research Institutes and Company R + D Entities in Germany were enabled to treat the following aspects: * Meteorological, system and cost investigations, * Development of important components as concentrator, receiver, storage, * Utilization of solar energy for process heat and chemical reactions. Besides the continued development of terminal concentrators, the studies concentrated in 1991 on the development of solar chemistry processes. The reports of the activities were finalized recently and collected in the present volume. The final reports were printed as received. The achieved results and the views expressed within the reports were under the responsibility of the authors. As organizers of these solar thermal activities and as editors of the corresponding final reports, we would like to thank BMFT and KFA-BEO for the farsighted funding (grant no. 0328823A) and the research groups for their engagement and consultations. We would also like to thank Ms S. Preusser and Ms U. Rachow, who among many others contributed to the realization of this volume.

The German R + D program "Solares Testzentrum Almeria" (SOTA) provides the scientific basis for the realization of advanced solar technologies including facility modifica-tions, component tests and new lines of development. One of the working packages, WP 300, addresses the "Scientific Support" by the performance of pre-paratory studies, exploratory laboratory activities and quali fied expertise. Universities, Research Institutes and Company R + D Entities in Germany are enabled to treat the following aspects: * Meteorological, system and cost investigations, * Development of important components as concentrator, receiver, storage, * Utilization of solar energy for process heat and chemical reactions. In 1990 the studies covered the developments of terminal concentrators, receivers, integrated receiver/reactors, and solar chemistry processes. The reports of the activities were finalized recently and collected in the present volume. The final reports were printed as received. The achieved results and the views ex-pressed within the reports were under the responsibility of the authors. As organizers of these solar thermal activities and as editors of the corresponding final reports, we would like to thank BMFT and KFA-BEO for the farsighted funding (grant no. 0328823A) and the research groups for their engagement and consultations. We would also like to thanl< Ms S. Preusser and Ms U. Rachow, who among many others contributed to the realization of this volume.

Sie beinhaltet zum einen die Fortsetzung und abschliessende Bewertung der Materialuntersuchungen zum Bau eines Sckundarkonzentrators (feil I Vertragsnr. 5-370-4355), zum anderen werden der Bau mehrerer Vormodelle zu den mog- lichen Konzentratorformen und Messergebnisse zu diesen Modellen vorgestellt, wo- bei unter Berucksichtigung der aufwendigen Fertigung der harten Spiegelbasis- materialien zur Kostenersparnis Iinearisierte Formen untersucht wurden, mit und ohne Teilbereich mit keramikahnlichen optischen Eigenschaften (Glanzkarton). Polierte Keramik in unbeschiehteter Form ist nur bedingt einsetzbar, da sie bei nahezu senkrechtem Strahlungseinfall einen direkten Reflexionsgrad von ca 9% zeigt (A1 TiO ). Die 27T-Reflexion dagegen kann fur weisse, reine Keramik uber 90% 2 s liegen (Hartporzellan). Erst durch Beschichtungen lassen sich die Werte fur die direkte Reflexion deutlich erhohen, wobei die Oberflachenbeschaffenheit eine we- sentliche Rolle spielt. Eine Beschichtung von TiN auf Glas erzielt Werte uber 90%, jedoch ist diese Schicht nicht uber das gesamte Sonnenspektrum einsetzbar. Ausserdem ist die Schicht oxidationsgefahrdet, eine zusatzliche Goldschicht ware moglicherweise ein Schutz dagegen. Bei den Modellen ( CPC, Trumpet ) wurde die Intensitatsverteilung in einigen Schnitten in der Austrittsapcrtur aufgenommen, zum Teil bei unterschiedlichen Einfallswinkeln. Daraus wurde die Verstarkung innerhalb der Schnitte und der Fluss im Vergleich zum Zustand ohne Konzcntrator ermittelt. Durch den Einsatz einc.