SPICA infrared coronagraph for the direct observation of exo-planets

We present a MIR coronagraph to target the direct observation of extrasolar planets for SPICA, in which a coronagraph is currently regarded as an option of the focal plane instruments. The primary target of the SPICA coronagraph is the direct observation of Jovian exo-planets. A strategy of the baseline survey and the specifications for the coronagraph instrument for the survey are introduced together. The main wavelengths and the contrast required for the observations are 3.5-27um, and 10^{-6}, respectively.Laboratory experiments were performed with a visible laser to demonstrate the principles of the coronagraphs. In an experiment using binary-shaped pupil coronagraphs, a contrast of 6.7x10^{-8} was achieved, as derived from the linear average in the dark region and the core of the PSF. A coronagraph by a binary-shaped pupil mask is a baseline solution for SPICA because of its feasibility and robustness. On the other hand, a laboratory experiment of the phase induced amplitude apodization/binary-mask hybrid coronagraph has been executed to obtain an option of higher performance, and a contrast of 6.5x10^{-7} was achieved with active wavefront control.Potentially important by-product of the instrument, transit monitoring for characteization of exo-planets, is also described. We also present recent progress of technology on a design of a binary-shaped pupil mask for the actual pupil of SPICA, PSF subtraction, the development of free-standing binary masks, a vacuum chamber, and a cryogenic deformable mirror. Considering SPICA to be an essential platform for coronagraphs and the progress of key technologies, we propose to develop a mid-infrared coronagraph instrument for SPICA and to perform the direct observation of exo-planets with it.Comment: 37th COSPAR Scientific Assembly; Montreal, Canada 13-20 July 2008/Submitted to AS

Comparative study of manufacturing techniques for coronagraphic binary pupil masks: masks on substrates and free-standing masks

We present a comparative study of the manufacture of binary pupil masks for coronagraphic observations of exoplanets. A checkerboard mask design, a type of binary pupil mask design, was adopted, and identical patterns of the same size were used for all the masks in order that we could compare the differences resulting from the different manufacturing methods. The masks on substrates had aluminum checkerboard patterns with thicknesses of 0.1/0.2/0.4/0.8/1.6$\mu$m constructed on substrates of BK7 glass, silicon, and germanium using photolithography and chemical processes. Free-standing masks made of copper and nickel with thicknesses of 2/5/10/20$\mu$m were also realized using photolithography and chemical processes, which included careful release from the substrate used as an intermediate step in the manufacture. Coronagraphic experiments using a visible laser were carried out for all the masks on BK7 glass substrate and the free-standing masks. The average contrasts were 8.4$\times10^{-8}$, 1.2$\times10^{-7}$, and 1.2$\times10^{-7}$ for the masks on BK7 substrates, the free-standing copper masks, and the free-standing nickel masks, respectively. No significant correlation was concluded between the contrast and the mask properties. The high contrast masks have the potential to cover the needs of coronagraphs for both ground-based and space-borne telescopes over a wide wavelength range. Especially, their application to the infrared space telescope, SPICA, is appropriate.Comment: 21 pates, 12 figures, 2 tables, accepted to PAS

A Binary Shaped Mask Coronagraph for a Segmented Pupil

We present the concept of a binary shaped mask coronagraph applicable to a telescope pupil including obscuration, based on previous works on binary shaped pupil mask by \citet{Kasdin2005} and \citet{Vanderbei1999}. Solutions with multi-barcode masks which "skip over" the obscuration are shown for various types of pupil of telescope, such as SUBARU, JWST, SPICA, and other examples. The number of diffraction tails in the point spread function of the coronagraphic image is reduced to two, thus offering a large discovery angle. The concept of mask rotation is also presented, which allows post-processing removal of diffraction tails and provides a 360$^{\circ}$ continuous discovery angle. It is suggested that the presented concept offers solutions which potentially allow large telescopes with segmented pupil in future to be used as platforms for an coronagraph.Comment: 12 pages, 4 figure

Credit Crunch in East Asia: A Retrospective

In this paper, we explore the issue on credit crunch from a comparative perspective. Utilizing longer time series data, we investigate the existence of credit crunch in selected crisis-hit economies in East Asia over the period 1980-2002. We detected some episodes of credit crunch both before and after the Asian economic crisis. These episodes after the Crisis are somewhat different from those detected by previous studies on the issue. We, then, review the credit-crunch episodes in the broad macroeconomic context in order to assess our results in the longer-run perspective. We are well aware that financial liberalization has changed the financial environments of these countries more or less in due course. Even so, the mixed results we obtained on the existence of credit crunch do not suggest that the impact of the austerity programs on financial intermediation after the Asian Crisis was ambiguous. On the contrary, they implied that the impact of the programs were so severe that credit crunch or supply retrenchment was overwhelmed by a sharp fall in credit demand because of real and expected persistent overall economic depression.credit crunch, East Asia, Asian Economic Crisis, disequilibrium analysis

Monetary Transmissions Immediately after the Crisis in East Asia

We examine dynamic patterns of macroeconomic variables in East Asia immediately after the Asian financial crisis. Particularly, focusing on East Asia, we can identify their distinctive features from those of aggregate cross-country results. Also, we check with the financial crises in East Asia in the 1980s in order to make sure to what extent the contrast between the aggregate cross-country results and that of the Asian financial crisis comes from differences in time (external environment) or in country structure or both. Some distinctive features in East Asia include higher real interest rates in the crisis year, persistent output as well as investment slowdown, and different behaviors of trade and fiscal surpluses after the crisis. The results suggest that initial monetary tightening be responsible for the unexpectedly serious recession and that favorable external conditions and fiscal stimulus did contribute to the post-crisis real recovery even without credit recoveries.macroeconomic dynamics, East Asia, financial crisis

Microscopic surface structure of C/SiC composite mirrors for space cryogenic telescopes

We report on the microscopic surface structure of carbon-fiber-reinforced silicon carbide (C/SiC) composite mirrors that have been improved for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) and other cooled telescopes. The C/SiC composite consists of carbon fiber, silicon carbide, and residual silicon. Specific microscopic structures are found on the surface of the bare C/SiC mirrors after polishing. These structures are considered to be caused by the different hardness of those materials. The roughness obtained for the bare mirrors is 20 nm rms for flat surfaces and 100 nm rms for curved surfaces. It was confirmed that a SiSiC slurry coating is effective in reducing the roughness to 2 nm rms. The scattering properties of the mirrors were measured at room temperature and also at 95 K. No significant change was found in the scattering properties through cooling, which suggests that the microscopic surface structure is stable with changes in temperature down to cryogenic values. The C/SiC mirror with the SiSiC slurry coating is a promising candidate for the SPICA telescope.Comment: 25 pages, 6 figure

Radiale Stosswellentherapie - gibt es einen positiven Langzeiteffekt bei chronischer Plantarfasziits?

Einleitung: Plantarfasziitis ist mit 10% die häufigste Ursache für Fersenschmerzen. Menschen die an einer chronischen Plantarfasziitis leiden, sind oftmals eingeschränkt in der Belastbarkeit und ihrer Lebensqualität. Radiale Stosswellentherapie ist ein relativ neu beschriebenes Thema in der Forschung. Sie ist günstiger sowie auch weniger schmerzhaft und einfacher anzuwenden, als die herkömmliche fokussierte Stosswellentherapie. Ziel: Ziel der vorliegenden Arbeit ist zu eruieren, ob die radiale Stosswellentherapie bei Patientinnen und Patienten mit chronischer Plantarfasziitis eine positive Langzeitwirkung hat. Methode: Für die Beantwortung der Fragestellung wurde anhand von genau definierten Ein- und Ausschlusskriterien mittels den Datenbanken CINAHL Complete, MEDLINE via Ovid und PubMed drei Studien gefunden. Die anschliessende Studienbewertung erfolgte mit Hilfe der Beurteilungsinstrumente AICA und PEDro. Ergebnisse: Die radiale Stosswellentherapie erbringt gute Langzeitresultate bezüglich Schmerzen und Funktionseinschränkungen bei chronischer Plantarfasziitis. Auch Stosswellentherapie in Kombination mit plantarfaszienspezifischem Dehnen zeigte eine gute Langzeitwirkung. Schlussfolgerung: Sofern konservative Massnahmen bei chronischer Plantarfasziitis keine Besserung erzielten, ist die radiale Stosswellentherapie eine gute Möglichkeit, um eine allfällige Operation zu umgehen. Um den Effekt zu verstärken, kann zudem eine begleitende physiotherapeutische Massnahme, wie beispielsweise das Dehnen empfohlen werden.Introduction: With 10% plantar fasciitis proved to be the most common cause of heel pain. People suffering from chronic plantar fasciitis are often limited in their resilience and Quality of life. Radial shock wave therapy is a relatively new topic in research. It is cheaper, less painful and also easier to apply than conventional focused shock wave therapy. Aim: The aim of the present study is to determine whether radial shock wave therapy has a positive long-term effect in patients with chronic plantar fasciitis. Method: Based on precisely predefined inclusion and exclusion criteria, three studies were found to answer the question using the databases CINAHL Complete, MEDLINE via Ovid and PubMed. The subsequent study evaluation was carried out using the assessment tools AICA and PEDro. Findings: Radial shock wave therapy provides good long-term results with regard to pain and functional limitations in chronic plantar fasciitis. These results are reinforced by combining shock wave therapy with physiotherapeutic measures such as plantar fascia specific stretching. Reasoning: If conservative measures did not improve chronic plantar fasciitis, radial shock wave therapy would be a good way to avoid surgery. To enhance the effect, an accompanying physiotherapeutic measure, for example stretching, can be recommended