NW14A is a newly constructed undulator beamline for 100 ps time-resolved X-ray experiments at the Photon Factory Advanced Ring. This beamline was designed to conduct a wide variety of time-resolved X-ray measurements, such as time-resolved diffraction, scattering and X-ray absorption fine structure. Its versatility is allowed by various instruments, including two undulators, three diffractometers, two pulse laser systems and an X-ray chopper. The potential for the detection of structural changes on the 100 ps time scale at NW14A is demonstrated by two examples of photo-induced structural changes in an organic crystal and photodissociation in solution.

The magnetic states of Mn and Co atoms in Co-rich Co 2 MnGe Heusler alloy thin films facing an MgO barrier were studied by means of soft x-ray magnetic circular dichroism ͑XMCD͒. In particular, the Co 2 MnGe film-thickness dependence of the Mn and Co magnetic moments was investigated. With a decrease in the Co 2 MnGe film thickness to 1-2 monolayers ͑MLs͒, the spin magnetic moment of Mn decreased and the Mn L 2,3 -edge x-ray absorption spectra ͑XAS͒ showed a Mn 2+ -like multiplet structure in MnO, in contrast to samples thicker than 4 ML, indicating that the Mn atoms of the 1 and 2 ML samples were oxidized. The Co spin magnetic moment increased slightly with decreasing thickness. A Co 2+ -like multiplet structure in CoO was not observed in all the Co L 2,3 -edge XAS and XMCD, indicating that, even in the ultrathin samples, the Co atoms were not oxidized, and were more strongly spin polarized than those in the thicker samples. Co spin magnetic moments of 1.40-1.77 B larger than the theoretical value for ideal stoichiometric Co 2 MnGe ͑ϳ1 B ͒ and the Co-rich film composition imply the presence of Co antisites that would lower the spin polarization.

Articles you may be interested inAn in-vacuum x-ray diffraction microscope for use in the 0.7-2.9 keV range Rev. Sci. Instrum. 83, 033703 (2012);

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An insertion device, MPW♯13, which can be operated in both wiggler and undulator modes, is presently under construction at the Photon Factory (PF). When installed in the PF storage ring, this device will produce wiggler radiation in the hard x-ray region, and also undulator radiation in the vacuum-ultraviolet (VUV) and soft x-ray regions. The wiggler structure employs 27 magnetic poles with a period length of 18 cm. The maximum peak field of the device of 1.5 T is attained via the hybrid configuration of its magnetic poles. Calculations of the spectral brilliance of the device exhibits the following features: in the wiggler mode, the brilliance at 10 keV will exceed that of the PF bending magnet radiation by a factor of 30; and in the undulator mode it will be between 10 and 100 times higher, from 10 eV to 1 keV, utilizing up to the fifth harmonic.

The beamline for the circularly polarized synchrotron radiation at the 6-Ge V Accumulation Ring for the TRISTAN project is now under construction. The insertion device of this beamline was designed to produce circularly polarized x rays at the photon energy range of200 e V-I 00 ke V. The beamline is divided into the following three branches: ( 1) High resolution Compton scattering and magnetic Compton scattering experiments; (2) mUltipurpose experiments such as magnetic x-ray scattering and magnetic x-ray absorption; and (3) completely circularly polarized soft x rays.