November 2012 Archives

Dr. B. Beckhoff (Physikalisch-Technische Bundesanstalt, Germany) and his colleagues have recently published some successful applications of grazing-incidence X-ray fluorescence and near-edge X-ray absorption fine structure to nano-scale thin layers of chemically vapor deposited B_xC_yN_z on metallic Ni. For more information, see the paper, "Nondestructive and Nonpreparative Chemical Nanometrology of Internal Material Interfaces at Tunable High Information Depths", B. Pollakowski et al., Anal. Chem., 85, 193 (2013).

The X-ray free electron laser (XFEL) is a new type of light source, which can provide coherent, high-flux, ultra-short photon pulses in the soft and hard X-ray energy region. Until now, a long linear accelerator as well as long linear undulators have been thought indispensable, because the principle is based on the self amplified spontaneous emission (SASE). Indeed, both FLASH at DESY and LCLS at SLAC, which are the world's first X-FEL facilities in soft and hard X-rays, respectively, are facilities on a huge scale. Recently, Dr. Z. Huang (SLAC National Accelerator Laboratory, USA) and his colleagues have published a very interesting idea for a compact XFEL facility that uses an ultra-short pulse laser instead of an ordinary linear accelerator. It is known that laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread, which makes it difficult to consider XFEL applications. Their main strategy is the introduction of a transverse field variation into the FEL undulator. In their calculation, such a transverse gradient undulator together with a properly dispersed beam can greatly reduce the effects of electron energy spread and jitter on the performance of XFEL generation. For more information, see the paper, "Compact X-ray Free-Electron Laser from a Laser-Plasma Accelerator Using a Transverse-Gradient Undulator", Z. Huang et al., Phys. Rev. Lett. 109, 204801 (2012).

A German group at Karlsruhe Institute of Technology has recently reported a quick X-ray diffraction experiment during laser surface hardening of materials. They employed a single exposure setup with two fast silicon strip line detectors (Mythen 1K, Dectris Ltd.), allowing for stress analysis according to the sin²ψ profile, and the measurements were done at beamline P05, PETRA III, DESY, Hamburg in Germany. A 6 kW diode laser was used for hardening of the material at a heating/cooling rate of 1000 K/s. In the paper, they described how they can perform high-resolution strain analysis by separating elastic and thermal strains. For more information, see the paper, "Fast in situ phase and stress analysis during laser surface treatment: A synchrotron x-ray diffraction approach", V. Kostov et al., Rev. Sci. Instrum., 83, 115101 (2012).

A French group has recently published an interesting report on the analysis of cirrhotic liver tissue. At the Synchrotron Soleil, near Paris in France, scientists combined synchrotron Fourier transform infrared (FTIR) microspectroscopy and synchrotron micro-X-ray fluorescence (XRF) on the same tissue section. They found from FTIR that hepatocytes within cirrhotic nodules have quite highly concentrated esters and sugars, and in the same area, phosphorus and iron were detected by XRF. Also the research team studied their inhomogeneity. For more information, see the paper, "In situ chemical composition analysis of cirrhosis by combining synchrotron-FTIR and synchrotron X-ray fluorescence microspectroscopies on the same tissue section", F. Le Naour et al., Anal. Chem., Just Accepted Manuscipt. Publication Date (Web): 3 Nov 2012.

The recipient of the 7th Asada Award, which is presented by the Discussion Group of X-ray Analysis, Japan, in memory of the late Professor Ei-ichi Asada (1924-2005) to promising young scientists in X-ray analysis fields in Japan, is Dr. Shinsuke Kunimura (Tokyo Univ. of Science, "Development of a portable TXRF spectrometer with pg detection limits and its applications"). The ceremony was held during the 48th Annual Conference on X-Ray Chemical Analysis, Japan, at Nagoya University, Nagoya.