October 2007 Archives

Dr. B. Beckhoff (Physikalisch-Technische Bundesanstalt, Berlin, Germany) and his colleagues have successfully performed a reference-free quantitation by total reflection X-ray fluorescence (TXRF) analysis in the soft X-ray region. So far, element determination by XRF has been usually done with a calibration curve, which requires some reference samples. However, there have been increasing demands for reference-free analysis, particularly in cases where stable and reliable reference samples are not easily obtained. The fundamental parameter method, which is one of the most promising ways of performing such reference-free analysis, uses the theoretical XRF intensity expressed by Sherman's equation (or Fujino-Shiraiwa's formula), but appears to be highly dependent on geometrical factors, the spectral distribution of primary X-rays, and atomic fundamental constants etc. In TXRF, the intensity is affected by additional conditions. The experiments were done with monochromatic synchrotron radiation, at BESSY II. The research group has developed a feasible sample chamber specially designed for quantitative XRF. In addition, several calibrated detector systems have been employed to obtain reliable results. For more information, see the paper, "Reference-Free Total Reflection X-ray Fluorescence Analysis of Semiconductor Surfaces with Synchrotron Radiation", B. Beckhoff et al., Anal. Chem. 79, 7873 -7882 (2007).

FLASH, which is the European free-electron laser (FEL) facility located in DESY's campus in Hamburg, recently achieved a world first by generating flashes of laser light at the wavelength of 6.5 nm, which is much shorter than the previous record of 13.5 nm that the same facility established one year ago. During the past several months, the linear accelerator (260 m) has been extended by a further 12 m by installing the 6th superconducting module. This has enabled the acceleration of the electron beam up to 1 GeV, the designed energy. The FLASH facility has been available for user experiments since August 2005. Until 2009, it will be the only facility in the world that can provide FEL in the soft X-ray region. The next user run will begin in mid-November this year and last 13 months. The international expert committee has already selected 32 projects. The present 6.5 nm soft X-ray laser will be used for the experiments. For further information, contact Petra Folkerts, Phone: +49 40-8998-4977, Fax: +49 40-8998-2020, presse@desy.de, http://www.xfel.eu

The Center for Nanoscale Materials (CNM) at the Department of Energy's Argonne National Laboratory has been declared fully operational. The CNM building opened for research in May 2006 and, since then, approximately 50 user projects have been able to take advantage of the facility. Very recently, the hard X-ray nanoprobe beamline was completed, and a Beowulf-class supercomputer array with 12 teraflop capacity installed. For further information, contact Steve McGregor, Phone: +1-630-252-5580, media@anl.gov, http://www.anl/gov/