Australian scientists have built and installed an X-ray powder diffractometer of an unusual design on the Australian beamline at the Photon Factory synchrotronradiation facility within the National Laboratory for High Energy Physics (KEK), Tsukuba, Japan. The diffractometer is a Debye-Scherrer camera of 0.573 m radius. The place of the cylindrical film in a conventional camera of this type is taken by image plates. To minimize scattering and absorption by air, the instrument can be evacuated. The instrument is now in operation and has been tested with a specimen of the rutile phase of TiO2. This material has been thoroughly studied previously and it has been demonstrated that time-of-flight neutron powder diffraction, conventional neutron powder diffraction, single-crystal neutron diffraction and single-crystal X-ray diffraction lead to a consistent set of values for the anisotropic thermal parameters and the one positional parameter. The powder specimen of rutile for use at KEK was diluted with gum tragacanth and inserted into a glass capillary of 0.5 mm diameter. The beam from the synchrotron is incident on a silicon (111) channel-cut monochromator. Data were collected to +165°20 at wavelengths of 0.62, 1.10, 1.54 and 1.90 A. The exposure time for each data set was 10 min. The resolution of the instrument agrees with theoretical prediction and is such that the full width at halfmaximum of a reflection varies from 0.04 ° at 20°20 to 0.2 ° at 160°20 for a wavelength of 1.54 A. The intensity from a 10 min exposure is more than sufficient for Rietveld refinement (Rexp < 1%).

%e compare new high-resolution inverse-photoemission spectra of the unoccupied surface states on Cu{001) with a first-principles calculation of the same surface. This theoretical calculation includes the asymtotic long-range image potential. The commonly observed image state is found to correspond to the n =1 member of the Rydberg series of states derived from the image potential, i.e. , the wave function has a single extremum beyond the crystal edge characteristic of the hydrogenic n = 1 state. Agreement between theory and experiment for aQ states is excellent. The experimentally determined binding energies and effective masses are 0.62 eV and 0.98m, for the n =1 image state and 0.8 eV {with respect to Ep) and 0.4m, for the n =0 surface resonance. The results indicate that surface corrugation effects are negligible.

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The Imaging and Medical beamline at the Australian Synchrotron achieved ;first light' in December 2008. Here, the first experiments performed on the beamline are reported, which involved both X-ray imaging and tomography studies for a range of samples. The use of a plastic-edge phantom for quantitative measurements of contrast and resolution proved to be very instructive and helped to confirm certain parameter values such as the effective horizontal source size, detector resolution and average X-ray energy for the polychromatic beam.

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We present photoemission spectra from the 3p level of Cu(lOO) obtained in coincidence with the MiW Auger line. The 3p level is narrowed from its 2.2-eV core-lifetime-broadened width to 1.0 eV, representing the intrinsic width of the l G Auger final state. The core line changes its energy within the 2.2-eV envelope as the Auger coincidence energy is changed, conserving the sum of Auger-electron and photoelectron kinetic energies.PACS numbers: 79.60.Cn, 71.50.+t Auger-photoelectron coincidence spectra were first reported by Haak and co-workers. 1 Many potential enhancements of ordinary photoelectron and Augerelectron spectroscopies are described in the original papers. l Most are based on the extra discrimination provided by knowing which subpeak in the Auger spectrum is associated with which subpeak in the photoelectron spectrum. Also suggested was the possibility that corehole lifetime broadening could sometimes be eliminated from the photoelectron spectrum. This is an especially exciting possibility, because the short Auger decay lifetime of core holes in solids can lead to broadening of more than an eV, obscuring interesting structure associated with chemical shifts, surface shifts, many-body structure, line shape, etc. 2 Poor instrumental energy resolution has previously prevented an experimental verification of this suggestion. In this paper we present data from the Cu(lOO) 3p core line in coincidence with the M3W (3p3d3d) Auger line illustrating this effect. The 3p linewidth is narrowed from 2.2 to 1.0 ±0.2 eV. We believe that this 1.0 eV is the lifetime width of the l G Auger final state.In this technique two electron energy analyzers are focused on one x-ray or uv illuminated sample. One analyzer is tuned to the energy of a core photoelectron and the other is tuned to an appropriate Auger decay energy. An event is recorded only when electrons are received in each analyzer simultaneously. This is interpreted to mean that both electrons are associated with the same photoexcitation event. Experimental details will be provided in another paper. 3 Briefly, commercial double-pass cylindrical-mirror analyzers 4 were set to 60-eV pass energy with 1-mm (small) apertures. One was fixed at a characteristic Auger energy, and the other was swept through the photoelectron spectrum. The 150-eV light from the National Synchrotron Light Source vacuum ultraviolet ring, was monochromatized by the U14 plane-grating monochromator. 5 The energy resolution, electron plus photon, in each system was <0.5 eV. The Auger (photoelectron) analyzer pulses provided starts (stops) for a time to amplitude converter. The output from the converter was analyzed by a multichannel analyzer. This provided output pulses for zero time delay (coincidence) and 180-ns time delay, each ±10 ns. The 180-ns delay pulses (one revolution time in the storage ring) were used to subtract accidental coincidences from the spectra. The sample was sputtered and annealed once per day. No contamination was visible in electron stimulated Auger spectra. Each coincide...

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A multiple imaging-plate (IP) detector system and focusing monochromator have been developed and successfully applied to the time-resolved study of phase transitions in Langmuir-Blodgett (LB) films by grazing-incidence X-ray diffraction (GIXD). The first reported application of imaging plates to a GIXD study was carried out by our group and proved to be very successful in the determination of thin-film structure [Foran, Peng, Steitz, Barnes & Gentle (1996). Langmuir, 12,[774][775][776][777]. To extend the capabilities of this system, an IP camera was designed and built which can accommodate up to 13 IPs (40 × 20 cm) inside the vacuum chamber of the main diffractometer at the Australian Beamline at the Photon Factory. The camera allows the enclosed IPs to be successively exposed and stored inside the diffractometer for later scanning. The focusing monochromator employed in this technique combines fixed exit-beam height with sagittal focusing of the second crystal and delivers a gain in flux of >20 times when measured through a 0.1 × 0.1 mm aperture. The utility of the system incorporating the IP camera and the focusing monochromator has been demonstrated through the study of temperature-dependent phase transitions in LB films of metal fatty acids.