Preface: Phys. Status Solidi B 246/7

AbstractDr. Walter Braun inspecting a mirror device (construction of the TGM 2 beamline at BESSY I in 1982) The following collection of 15 publications is dedicated to Dr. Walter Braun on the occasion of his 60th birthday. The contributions were written by close friends and colleagues who collaborated with Walter Braun very often for a very long time. Since Walter Braun is known to many people as the key person at BESSY (now the Helmholtz‐Zentrum Berlin) who looks after the users and organises their beam times, the work presented, of course, all deals with synchrotron radiation research. The selected publications thus cover a wide range of synchrotron applications predominantly in the fields of surfaces, interfaces, semiconductors, and material science. So we believe that this collection also well mirrors the breadth of research fields which were and are influenced by Walter Braun's activities at BESSY. Everyone who ever visited BESSY I in Berlin‐Wilmersdorf or BESSY II in Adlershof as a user knows Walter Braun very well as he usually gets in touch with users and offers his support. But it is not just the usual user support or coordinating beam times, it is much more than this which distinguishes Walter Braun from many others. He formed and forms networks of researchers by setting up contacts and bringing people together. With his excellent judgement of people he has the right flair for those who can co‐operate well. It is fair to say that Walter Braun in such a way had and has great influence on the scientific development at BESSY and thus also on its success. Many of us are grateful to Walter Braun not only for his support for all these years and his permanent encouragement but also for his friendship (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)