A quarter-century of metrology using synchrotron radiation by PTB in Berlin

For more than 25 years, the Physikalisch-Technische Bundesanstalt has been strongly engaged in the field of metrology using synchrotron radiation. In Berlin, this research programme started together with the user operation of the electron storage ring BESSY I in the early 1980s. At the beginning, the work was focused on fundamental radiometry, i.e. using the storage ring as a primary radiation source standard and operating beamlines for source and detector calibration in the vacuum ultraviolet spectral range. Meanwhile, at the electron storage rings BESSY II and Metrology Light Source in Berlin-Adlershof, the activities have been extended to a broad range of fundamental and applied photon metrology in the range from the far infrared to hard X-rays, including methods like cryogenic radiometry, reflectometry and X-ray fluorescence spectroscopy. In the present review, we give a short historical introduction to this work, describe our laboratories and the basic radiometric principles, and present examples of recent applications, largely performed within the framework of scientific cooperations with external partners from industry and research. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)