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Notes: A scanning x-ray microscope using circularly polarized radiation has been constructed at the beamline NE1B of the 6.5-GeV TRISTAN accumulation ring (AR). It uses a Fresnel zone plate as an x-ray focusing lens. Its spatial resolution has been evaluated to be ∼1.2 μm at the energy of 933 eV. Depending on the relative orientation between the photon spin and the local magnetization direction, the magnetic domains recorded in a piece of videotape have been successfully observed visually at the L2,3 absorption edges of cobalt. The contrast of the image arises from the magnetic circular dichroism in core-level photoemission of ferromagnets. The observed contrast was certainly reversed between L2 and L3 edges. © 1995 American Institute of Physics.

Notes: Summary. Ovarian arterial velocimetry, using real-time two-dimensional and pulsed Doppler ultrasound, was performed on 36 occasions in nine healthy women with regular menstrual cycles. The change in ovarian arterial compliance was based on the calculation of pulsatility index (PI). In the active ovary carrying a dominant follicle or corpus luteum, the PI in the early follicular phase (mean 6.97, SD 2.01) was significantly higher than that in the late follicular phase (mean 2.36, SD 0.31) (P〈0.001), and the PI in the early luteal phase (mean 0.68, SD 0.09) was significantly lower than that in the late follicular phase (P〈0.001). The PI in the late luteal phase (mean 0.93, SD 0.16) was significantly higher than that in the early luteal phase (P〈0.01). In the inactive ovary, no cyclical changes were seen in the values of PI. There was a significant difference between the values of PI in the active ovary and the inactive ovary in the late follicular, the early and the late luteal phases [2-36 (SD 0-31)] vs [6-29 (SD 1-02)], [0-68 (SD 0.09)] vs [6.18 (SD 1.33)], [0.93 (SD 0.16) vs [6-57 (SD 1.72)] (P〈0.001), respectively. Use of non-invasive Doppler ultrasound to study physiology of ovarian haemodynamics during the menstrual cycle is of great clinical relevance and paves the way for further investigations on sterility.

Notes: Absorption spectra as microspectroscopy taken inside single magnetic domains of nickel have been achieved in the 2p–3d excitation region with a 1 μm spot of circularly polarized undulator radiation focused by a scanning x-ray microscope. A sample used as demonstration was a deposited nickel layer. It was confirmed that the spectra exhibited the features corresponding to the opposite magnetization of each domain using the fixed circular polarization. This technique can offer element- and domain-specific x-ray magnetic microspectroscopy in a submicrometer scale. © 1996 American Institute of Physics.

Notes: Solid-phase-epitaxial (SPE) regrowth from selectively As+-implanted amorphous Si is analyzed by cross-sectional transmission electron microscopy. SPE regrowth in the (100) wafers proceeds into both vertical and lateral directions simultaneously. For (111) samples, SPE regrowth in the diagonal direction, i.e., 〈100〉 direction near the mask edge, is dominant. In addition to the end of range defects and projected range defects, in the SPE process, defects of a third type are generated just beneath the implantation mask edge. Differences in mask material which control the applied stress at the mask edge have little influence on edge defect generation. Substrate orientation and mask pattern direction play important roles in the edge defect formation mechanism.

Notes: The characteristics of microchannel plates (MCPs) for detection of x rays have been investigated using synchrotron radiation in the energy ranges from 0.6 to 2.0 keV and from 5 to 20 keV. Microchannel plates are operated under the condition of an unsaturated pulse-height distribution mode. The current response curve of MCPs is measured continuously with x-ray energy variation for the first time. The experimental result of some discontinuous jumps in the response is obtained at the energies corresponding to the absorption edge of the MCP materials. In the low-energy range (hν〈2 keV), the dependence of the current response to the incident angle of x rays to the channel axis θ is measured to be proportional to cot θ, which is interpreted by the x-ray absorption near the surface of MCP channel wall. While, in the high-energy range (hν〉5 keV), a weak dependence on θ is observed, and is attributed mainly to the penetration of x rays through multiple channels.

Notes: A soft x-ray microscope has been developed at the beamline NE1B of the 6.5-GeV TRISTAN Accumulation Ring (AR). It makes use of undulator radiation as its source and a zone plate with the outermost zone width of 50 nm as its imaging element. It has two main features. First, the undulator radiation is monochromatized by a grazing incidence grating monochromator to match to the monochromaticity requirement of the zone plate. Second, a visible light prefocus unit consisting of two objectives has been designed and installed in the x-ray microscope. The x-ray optical system of the microscope can be adjusted easily, quickly, and precisely by using this unit. The microscope can resolve 55-nm lines and spaces in a zone plate test pattern. © 1995 American Institute of Physics.

Notes: Current response characteristics of microchannel plates (MCPs) x-ray detectors have been measured in a wide energy range from 0.6 to 82 keV using synchrotron radiation. In the current response curve with continuous photon energy, some discontinuities have been observed to correspond to absorption edges of elements which are the constituents of MCP glass and electrode materials (Si, Pb, Ba, and Fe). The dependence of the MCP response on the incident angle of x rays to the channel axis, θ, is also investigated. The characteristics change from the cot θ dependence for soft x rays (hν〈4 keV) to the sec θ one for hard x rays (hν〉60 keV). These results could provide guidelines on the design of x-ray diagnostic instruments using MCPs.

Notes: The characteristics of microchannel plates (MCPs) for detection of x rays have been investigated using synchrotron radiation in the energy range from 1.8 to 8 keV. The current response curve of MCPs is measured with approximately continuous x-ray energy variation, which is added to the previous data [T. Kondoh et al., Rev. Sci. Instrum. 59, 252 (1988)]. It is confirmed that there is a minimum in the current response at the x-ray energy of about 4 keV. The precise current response curve has been completed for the wide x-ray energy range from 0.6 to 20 keV. A transition in the incident angle dependence of current response is found from the feature based on single cylindrical photocathode model for soft x rays to that based on multiple channel activation due to the penetration of x rays through channel walls for hard x rays. In the current response of MCPs the structure similar to that in EXAFS is observed near the Si K edge.

Notes: The characteristics of microchannel plates (MCPs) for x-ray detection have been investigated with continuous x-ray energy variation using synchrotron radiation in the XUV and soft x-ray region (from 60 to 600 eV). The current response data have shown x-ray absorption fine structure (EXAFS or XANES) near the oxygen K absorption edge as well as a jump structure near the silicon L edge; these structures are explained by the surface composition of channel walls (SiO2). The data show that the surface layer of a microchannel is essential for x-ray detection by MCPs in this energy range. The precise current response curve has been completed for the wide x-ray energy range from 0.06 to 82 keV combined with the previously reported data [Kondoh et al., Rev. Sci. Instrum. 59, 252 (1988); Cho et al., ibid. 59, 2453 (1988); Yamaguchi et al., ibid. 60, 368, 2307 (1989)].

Notes: Using undulator radiation from 2 to 8 keV, quantum efficiencies [QE(E)] of gold photocathodes, microchannel plates (MCP), and silicon surface barrier (SSB) detectors have been investigated. For the gold photocathodes, the detailed structure of QE(E) near the M absorption edges has been presented. Also, the secondary electron conversion efficiency of gold has been calculated using the mass absorption coefficient given by a relativistic Hartree–Slater model and by the semiempirical values of Henke et al., respectively. Extended x-ray absorption fine structure (EXAFS) has been observed in the secondary electron current of the gold photocathode as well as in the detection current responses of an MCP and of an SSB detector. Furthermore, the new findings adding to our recent paper1 have been summarized as follows: (i) EXAFS above the Si-K edge in the MCP response depends on photon incident angles, and (ii) a little upshift of the starting point energy of EXAFS in the MCP response is observed. These detailed characteristics and their interpretation are described in the following: (i) The current responses of the MCP are obtained as a function of the incident x-ray energy for θ=13° (the bias angle of the MCP), and 40° by using a gold-monitor current. Here, θ denotes the incident angle of the photons to the channel. The data for θ=40° show a smaller jump near the Si-K edge as compared with the data for θ=13°.This is explained as follows: The incident photons for θ=13° are irradiated to and absorbed in the MCP ingredient of SiO2, while photons for θ=40° are incident to the electrode region. (The depth of the electrode coating is more than 10 μm from the MCP surface, while the photons are absorbed at less than 8 μm from the surface for θ=40°.) Thus, the data for θ=40° strongly reflect the characteristics of the electrode, but not of SiO2. The data for several values of θ consistently indicate that the height of this jump becomes smaller with increasing θ. (ii) The observed upshift of the starting point energy of EXAFS in the MCP response presents a contrast to EXAFS in the SSB detector response, in which upshift is not observed. This upshift is ascribed to the molecular structure of SiO2 (the chemical shift); that is, some valence electrons are removed from the Si atoms due to the oxidation (i.e., SiO2). Thus, the screening effects of the valence electrons on the core electron-nucleus attraction are reduced. This results in the shift of binding energy towards the higher-energy side. On the other hand, EXAFS in the SSB detector response reflects the characteristics of Si.