Annual Report 2004

This report documents the scientific and technical activities at the ion beam laboratory ISL. The main task of the department SF4, Structure and Dynamics are the operations of ISL but, in addition, the department s scientists run activities also at the synchrotron radiation facilities BESSY and HASYLAB and use radioactive beams at ISOLDE, CERN. Scientifically, a very successful year has passed due to the excellent performance of the accelerators in 2003 and 2004 allowing many new experiments concerning the irradiation of samples with very high doses with beams of very heavy ions. These irradiations lead to unpredicted self organisations of the surfaces and seem to open up a new dimension in the field of ion beam induced materials modifications. Other exciting new results have been obtained using the analysing power scattering and diffraction of synchrotron radiation for ion beam induced structure modifications, showing that this combination of tools is marking the steps into the right direction. Albeit the well prepared programme for the ion beam physics which has been presented together with the activities at GSI, ISL did not find the final funding. The reviewers welcomed the scientific value and the synergy of the two centres concerning the ion beam activities, but the Helmholtz Senat voted for the shutdown of the ISL facility by the end of 2007 for the following reasons The scientific perspectives had been rated low since the Hahn Meitner Institut Berlin would not foresee a future appointment of a scientific leader. In addition, though the users gave us a high ranking in terms of reliability and flexibility the official rating for ISL s commitment was low because the Hahn Meitner Institut Berlin did not agree to a rather moderate increase of the manpower to produce more hours per year of beam on target. We don t like to comment on these issues. There have been many letters of support of many institutions and high ranking individuals to all decision making institutions and individuals but so far they were all in vein. The time table for shut down has even been set forward to the end of 2006. Thus, we have to conclude that the idea of a dedicated ion beam facility producing fast ions with the appropriate equipment for ion beam applications in basic and applied research in solid state physics, materials science, and medicine could not be convincingly transferred to the decision making authorities. The readers of this report may develop their own point of view. The message for the users of ISL is that we will continue full operation until the end of 2006. Users may still send in proposals to the Meeting of the Nutzerausschuss, October 2005, and can try to finish their scientific programmes. Berlin, June 2005 Heinrich Homeye

Modelica and functional mock-up interface : Open standards for gas turbine simulation

This paper introduces two physical modeling standards in the gas turbine and cycle analysis context. Modelica is the defacto standard for physical system modeling and simulation. The Functional Mock-Up Interface is a domain-independent standard for model exchange (“engine decks”). The paper summarizes key language concepts and discusses important design patterns in the application of gas turbine simulation concepts to the acausal modeling language. To substantiate how open standards are applicable to gas turbine simulation, the paper closes with two application examples, a conventional unmixed turbofan thermodynamic cycle and weight analysis as well as an electrically boosted geared turbofan