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Metrology Light Source now ready for use

Especially interesting for
  • the semiconductor industry
  • materials science
  • astronomy

The Metrology Light Source (MLS) is an electron storage ring which has been constructed by the former BESSY company in Berlin-Adlershof for PTB for the production and use of synchrotron radiation. It is particularly well-suited for the IR, UV, VUV and EUV spectral ranges. Since its commissioning in 2008, PTB has set up a total of 12 experimental stations on 7 beamlines for metrology with synchrotron radiation at the MLS. All of them are now ready for use.

View into the experimental hall at the MLS: four beamlines

The use of the MLS, as a primary source standard, offers unique measurement capabilities when it comes to characterizing energy-dispersive detector systems such as, e.g., spectrometers or fi lter radiometers, and calibrating singlephoton detectors as well as UV/VUV sources. To this end, besides a beamline for direct bending magnet radiation, also experimental stations for electron energy measurements and electron beam diagnostics have been set up. A UV/VUV experimental station for source calibration has recently been put into operation.

The UV/VUV beamline for detector calibration and refl ectometry was already commissioned in 2008. It had been transferred from the nearby electron storage ring "BESSY II" to the MLS. Here, measurements are performed within the scope of services and research cooperations, for example to characterize telescopes for solar and atmospheric research. By using a longperiod undulator at the MLS, high-intensity and fully polarized radiation can be generated in the spectral range from IR to the near-VUV. This provides new measurement capabilities (for example, for polarization experiments such as UV/VUV ellipsometry) which are otherwise rare in Europe.

One focus of the cooperations with industry at the MLS will be EUV lithography. Activities in this fi eld, which had, to date, already been very exhaustive, encompass the characterization of multilayer mirrors, collector optics, refl ection masks and detection systems for EUV radiation at a wavelength of 13.5 nm. Due to the transfer of the large-scale EUV refl ectometer from the PTB laboratory at BESSY II to the EUV beamline at the MLS, these activities will be relocated in 2013.

Contrary to UV, VUV and EUV, in which PTB has long years of experience, the activities with regard to synchrotron radiation in the IR and THz spectral ranges, which are planned at the MLS, are all in all new. The two respective beamlines were commissioned early. For experiments in the fi eld of microspectrometry, high-end instruments are available: a fast Fourier-Transform-IR (FTIR) spectrometer and a high-resolution IR microscope. Especially in the THz spectral range, the measurement conditions at the MLS are ideal as the MLS is the fi rst electron storage ring to have been optimized for generating coherent THz radiation.

With the recently set-up instruments, the usage of the MLS – for radiometric purposes – is to be extended to new fi elds of research such as, e. g., materials analysis and materials sciences. Hereby it is planned, in cooperation with external partners, to take on new measuring technologies such as near-fi eld microscopy, ellipsometry or electron spectroscopy.


Gerhard Ulm
Division 7 Temperature and Synchrotron Radiation
phone: +49 (0) 30 3481-7312
e-mail: gerhard.ulm(at)ptb.de

Scientific publication

Gottwald, A.; Klein, R.; Müller, R.; Richter, M.; Scholze, F.; Thornagel, R.; Ulm, G.: Current Capabilities at the Metrology Light Source. Metrologia (2011). Im Druck