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Atmospheric-pressure plasma etching of a gallium nitride (GaN) substrate using hydrogen radicals instead of chlorine radicals was investigated toward the backside thinning of GaN vertical power devices to reduce on-resistance. As a basic experiment, a pipe-shaped electrode was placed facing the GaN substrate to generate atmospheric-pressure plasma of a gas mixture of helium and hydrogen and high-speed etching of approximately 4 μm min−1 was achieved. Although many spherical Ga metal particles were observed on the surface after processing, the addition of oxygen gas was found to be able to suppress them.

BACKGROUND Margin convergence has been shown to restore muscle tension in a cadaveric model of a rotator cuff tear. However, the clinical utility of this technique remains uncertain for patients with pseudoparalysis caused by an irreparable rotator cuff tear. QUESTIONS/PURPOSES (1) For patients with massive irreparable rotator cuff tears, in what proportion of patients does margin convergence reverse pseudoparalysis? (2) In patients with massive irreparable rotator cuff tears, does margin convergence improve American Shoulder and Elbow Surgeons (ASES) scores? (3) What is the survivorship free from MRI evidence of retear after margin convergence? METHODS Between 2000 and 2015, we treated 203 patients for pseudoparalysis with a rotator cuff tear. Pseudoparalysis was defined as active elevation less than 90° with no stiffness, which a physical therapist evaluated in the sitting position using a goniometer after subacromial injection of 10 cc lidocaine to eliminate pain. Of those, we considered patients who underwent at least 3 weeks of unsuccessful nonoperative treatment in our hospital as potentially eligible. Twenty-one percent (43 of 203) who either improved or were lost to follow-up within 3 weeks of nonoperative treatment were excluded. A further 12% (25 of 203) were excluded because of cervical palsy, axillary nerve palsy after dislocation or subluxation, and development of severe shoulder stiffness (passive shoulder elevation < 90°). Repair was the first-line treatment, but if tears were considered irreparable with the torn tendon unable to reach the original footprint after mobilizing the cuff during surgery, margin convergence was used. When margin convergence failed, the procedure was converted to hemiarthroplasty using a small humeral head to help complete the repair. Therefore, 21% (42 of 203) of patients treated with regular repair (18% [36 of 203]) or hemiarthroplasty (3% [6 of 203]) were excluded. That left 93 patients eligible for consideration. Of those, 13 patients were lost before the minimum study follow-up of 2 years or had incomplete datasets, and 86% (80 of 93) were analyzed (49 men and 31 women; mean age 68 ± 9 years; mean follow-up 26 ± 4 months). Seventy-six percent (61 of 80) were not evaluated in the last 5 years. We considered reversal of pseudoparalysis as our primary study outcome of interest; we defined this as greater than 90° active forward elevation; physical therapists in care measured this in the sitting position by using goniometers. Clinical outcomes were evaluated based on the ASES score from chart review, active ROM in the shoulder measured by the physical therapists, and the 8-month Kaplan-Meier survivorship free from MRI evidence of retear graded by the first author. RESULTS Pseudoparalysis was reversed in 93% (74 of 80) patients, and improvement in ASES scores was observed at the final follow-up (preoperative 22 ± 10 to postoperative 62 ± 21, mean difference 40 [95% CI 35 to 45]; p < 0.01). The 8-month Kaplan-Meier survivorship free from MRI evidence of retear after surgery was 72% (95% CI 63% to 81%). There were no differences in clinical scores between patients with and without retears (intact ASES 64 ± 24, re-tear ASES 59 ± 10, mean difference 6 [95% CI -5 to 16]; p = 0.27). CONCLUSION Margin convergence can be a good option for treating patients with pseudoparalysis and irreparable rotator cuff tears despite the relatively high retear rates. The proportion of pseudoparalysis reversal was lower in patients with three-tendon involvement. Further studies will be needed to define the appropriate procedure in this group. LEVEL OF EVIDENCE Level IV, therapeutic study.

Proceedings of the National Academy of Sciences of the United States of America 119(12), e2119616119 (2022). doi:10.1073/pnas.2119616119, Coherent nonlinear spectroscopies and imaging in the X-ray domain provide direct insight into the coupled motions of electrons and nuclei with resolution on the electronic length and time scale. The experimental realization of such techniques will strongly benefit from access to intense, coherent pairs of femtosecond X-ray pulses. We have observed phase-stable X-ray pulse pairs containing more than 3*107 photons at 5.9 keV (2.1 ��) with ~1 fs duration and 2-5 fs separation. The highly directional pulse pairs are manifested by interference fringes in the superfluorescent and seeded stimulated manganese K�� emission induced by an X-ray free-electron laser. The fringes constitute the time-frequency X-ray analogue of Young���s double-slit interference allowing for frequency-domain X-ray measurements with attosecond time resolution., Published by National Acad. of Sciences, Washington, DC

A focus characterization method using the intensity correlation of X-ray fluorescence is proposed, and demonstrated for the sub-micrometre focused X-ray free-electron laser beam at the SPring-8 Angstrom Compact Free Electron Laser., This paper proposes and demonstrates a simple method using the intensity correlation of X-ray fluorescence to evaluate the focused beam size of an X-ray free-electron laser (XFEL). This method was applied to the sub-micrometre focused XFEL beam at the SPring-8 Angstrom Compact Free Electron Laser, and the beam size evaluated using the proposed method was consistent with that measured using the knife-edge scan method. The proposed method is readily applicable to extremely small X-ray spots and can be applied for the precise diagnostics of sub-10 nm focused X-ray beams which have recently emerged.

Focusing of an X-ray free-electron laser enables the production of ultrahigh-intensity X-ray pulses. X-ray nanobeams of a free-electron laser were generated using reflective focusing optics combined with speckle interferometry., Ultimate focusing of an X-ray free-electron laser (XFEL) enables the generation of ultrahigh-intensity X-ray pulses. Although sub-10 nm focusing has already been achieved using synchrotron light sources, the sub-10 nm focusing of XFEL beams remains difficult mainly because the insufficient stability of the light source hinders the evaluation of a focused beam profile. This problem is specifically disadvantageous for the Kirkpatrick–Baez (KB) mirror focusing system, in which a slight misalignment of ∼300 nrad can degrade the focused beam. In this work, an X-ray nanobeam of a free-electron laser was generated using reflective KB focusing optics combined with speckle interferometry. The speckle profiles generated by 2 nm platinum particles were systematically investigated on a single-shot basis by changing the alignment of the multilayer KB mirror system installed at the SPring-8 Angstrom Compact Free-Electron Laser, in combination with computer simulations. It was verified that the KB mirror alignments were optimized with the required accuracy, and a focused vertical beam of 5.8 nm (±1.2 nm) was achieved after optimization. The speckle interferometry reported in this study is expected to be an effective tool for optimizing the alignment of nano-focusing systems and for generating an unprecedented intensity of up to 1022 W cm−2 using XFEL sources.

Bimodal behavior in the translational order of silicon's second shell in SiO

We present an analytic method for the calibration of X-ray fluorescence spectra collected using cylindrically bent crystal analyzers in any arrangement with respect to the sample and detector. Cylindrically bent analyzers are often used in the von Hamos geometry at X-ray Free Electron Lasers to image and disperse fluorescence from a point source to an easily calibrated line. When not in the von Hamos configuration, cylindrically bent analyzers produce spatio-spectral patterns that cannot be calibrated using existing methods. Our formula allows us to rapidly fit and optimize geometric parameters for fluorescence data and calibrate the resulting spectra.

A wavefront measurement method in the microscope (magnifying) geometry can help achieve the required high accuracy for deformable mirrors. This study proposes an image-based wavefront measurement method based on a series of images of a small area near the focus. In this method, phase retrieval calculation using multiple images is performed. A proof-of-concept experiment was performed using multilayer AKB mirrors and an FZP to form the small area. Consequently, wavefront aberration was successfully retrieved using 60 images of a 30-nm-diameter area near the focus.

In recent years, due to the widespread use of the Internet, the number of opportunities to search the Web using search engines has been increasing. In conventional search engines, information retrieval is achieved by repeatedly entering a query and selecting and browsing each page in the search engine result pages (SERPs). The search engines present titles, snippets, and other information to help users select suitable Web pages. However, there are cases in which people view Web pages one by one due to lack of prior knowledge or failure of search strategies. To solve this problem, we present keywords from unvisited results in the SERPs, so that users can predict the content of the Web pages. We propose two kinds of feature words as extended snippets to be presented in each search result: a content word to indicate the central content of a Web page and known-topic and unknown-topic words to indicate the degree of knowledge that one would gain by browsing the Web page. The extraction of those is based on the clustering of words in snippet sentences using the distributed representation of the words and the clustering of words in the visited pages, respectively. We investigated the impact of the proposed extended snippet on user search behavior. The experimental findings indicate that our method was useful in certain types of search, as it decreased the time necessary to complete the search. Furthermore, the participants' ratings of the extended snippets were favorable, especially those of the unknown-topic words.

To shorten the duration of x-ray pulses, we present a nonlinear optical technique using atoms with core-hole vacancies (core-hole atoms) generated by inner-shell photoionization. The weak Coulomb screening in the core-hole atoms results in decreased absorption at photon energies immediately above the absorption edge. By employing this phenomenon, referred to as saturable absorption, we successfully reduce the duration of x-ray free-electron laser pulses (photon energy: 9.000 keV, duration: 6-7 fs, fluence: 2.0-3.5$\times$10$^5$ J/cm$^2$) by $\sim$35%. This finding that core-hole atoms are applicable to nonlinear x-ray optics is an essential stepping stone for extending nonlinear technologies commonplace at optical wavelengths to the hard x-ray region.

We present ongoing efforts on the development of precision Wolter mirrors for the Soft X-ray Imaging Spectrometer (SXIS) aboard PhoENiX mission proposed to JAXA for studying mechanism(s) of particle acceleration and its relationship with magnetic reconnection in solar flares. The Wolter mirrors for PhoENiX/SXIS are made by direct polishing of glass-ceramic substrates. So far, we succeeded in fabricating a small size of high precision Wolter surfaces (e.g., PSF core size of ~0.2 arcsec HPD at 8 keV) as well as good indication of extending the mirror area along the cylindrical direction. Recent status of the mirror development will be reported.

To identify factors that influence post-exercise muscle glycogen repletion, we compared the glycogen recovery after level running with downhill running, an experimental model of impaired post-exercise glycogen recovery. Male Institute of Cancer Research (ICR) mice performed endurance level running (no inclination) or downhill running (−5° inclination) on a treadmill. In Experiment 1, to determine whether these two types of exercise resulted in different post-exercise glycogen repletion patterns, tissues were harvested immediately post-exercise or 2 days post-exercise. Compared to the control (sedentary) group, level running induced significant glycogen supercompensation in the soleus muscle at 2 days post-exercise (p = 0.002). Downhill running did not induce glycogen supercompensation. In Experiment 2, mice were orally administered glucose 1 day post-exercise; this induced glycogen supercompensation in soleus and plantaris muscle only in the level running group (soleus: p = 0.005, plantaris: p = 0.003). There were significant positive main effects of level running compared to downhill running on the plasma insulin (p = 0.017) and C-peptide concentration (p = 0.011). There was no difference in the glucose transporter 4 level or the phosphorylated states of proteins related to insulin signaling and metabolism in skeletal muscle. The level running group showed significantly higher hexokinase 2 (HK2) protein content in both soleus (p = 0.046) and plantaris muscles (p =0.044) at 1 day after exercise compared to the downhill running group. Our findings suggest that post-exercise skeletal muscle glycogen repletion might be partly influenced by plasma insulin and skeletal muscle HK2 protein levels.

Optical components in optics hutches of a hard x-ray undulator beamline of BL05XU at SPring-8 was restructured for providing a high flux beam at 1% bandwidth in the x-ray energy range from 5 to 100 keV. The so-called pink beam by a double-multilayer monochromator or total reflection mirrors pair with a prism made of glassy carbon as a harmonic separator are prepared in this beamline. The total reflection mirrors have three stripes; rhodium and platinum coated surface and silicon uncoated surface. Additionally, a silicon single crystal monochromator and a silicon channel cut crystal monochromator with liquid nitrogen cooling system are planned to be installed. The installation of these optical components started at January 2020. The commissioning of some components using undulator radiation will be started at April 2020.

Focusing x-ray free-electron lasers (XFEL) allows us to study nonlinear optics within the xray region. Recently, we challenged the focusing XFELs to below 10 nm. However, the conventional multilayer Kirkpatrick-Baez(KB) mirrors require too strict alignment accuracy of the incident angle. To solve this problem, we propose advanced KB (AKB) mirrors, based on Wolter type III geometry. Because the configuration satisfies the Abbe sine condition, AKB mirrors enables a tolerance of incident angle error 1000 times greater than conventional KB mirrors. The remaining problem is how such mirrors are to be fabricated, because required shape accuracy is below 1 nm and the small radius of curvature on the mirrors makes high accuracy shape measurement difficult. In this work, we performed a mirror fabrication procedure based on a combination of a grating interferometer and a differential deposition. Experiment at BL29XUL of SPring-8 demonstrated AKB mirrors with an accuracy of λ/4 fabricated.

We propose an extended X-ray adaptive zoom condenser that can form an intermediate virtual focus. The system comprises two deformable mirrors for focusing within a single dimension and can vary its numerical aperture (NA) without changing the positions of the light source, mirrors, or final focus. The desired system NA is achieved simply by controlling the mirror surfaces, which enables conversion between convex and concave forms, by varying the position of the intermediate virtual focus. A feasibility test at SPring-8 under a photon energy of 10 keV demonstrated that the beam size can be varied between 134 and 1010 nm.

Spatial resolution of full-field X-ray microscopes based on total-reflection mirrors was limited by grazing-incidence angle of the mirrors. At practical conditions, achievable spatial resolution is approximately 30 nm. To overcome the limitation, multilayer advanced Kirkpatrick-Baez mirrors and full-field X-ray microscopes with this objective mirrors have been developed in Osaka University and RIGAKU Corp. One of the remarkable points in this design is an achievable spatial resolution of less than 20 nm owing to large grazing-incidence angle and multilayer (Pt/C) with narrow period. Also, the advanced Kirkpatrick-Baez mirrors comprise two mirror pairs based on the Wolter type I and type III optics, respectively, to have sufficiently large magnification even at a compact setup with the whole length of 2 m (between a sample and a camera). The compactness makes it possible to apply the optics to laboratory-based X-ray microscopes, which is another ongoing project. A performance test using a Siemens star chart at an X-ray energy of 8 keV was performed in SPring-8 BL29XUL. The results showed lines with approximately 30-nm width could be resolved. Also, tests of stability and energy dependence confirmed usability of this system.

A method of fabricating multilayer focusing mirrors that can focus X-rays down to 10 nm or less was established in this study. The wavefront aberration induced by multilayer Kirkpatrick–Baez mirror optics was measured using a single grating interferometer at a photon energy of 9.1 keV at SPring-8 Angstrom Compact Free Electron Laser (SACLA), and the mirror shape was then directly corrected by employing a differential deposition method. The accuracies of these processes were carefully investigated, considering the accuracy required for diffraction-limited focusing. The wavefront produced by the corrected multilayer focusing mirrors was characterized again in the same manner, revealing that the root mean square of the wavefront aberration was improved from 2.7 (3.3) rad to 0.52 (0.82) rad in the vertical (horizontal) direction. A wave-optical simulator indicated that these wavefront-corrected multilayer focusing mirrors are capable of achieving sub-10-nm X-ray focusing.

In recent years, graphene growth technology has been greatly progressed, and it is possible to grow graphene with millimeter-size single crystals using metal-catalysis CVD. However, the transfer process is unavoidably which largely deteriorates the graphene. We have proposed direct precipitation method of graphene using a W capping layer. The method does not only require a transfer process, but also the introduction of wrinkles will be suppressed by optimizing the cooling rate at the graphene precipitation. The growth conditions such as thickness of amorphous carbon, annealing temperature, cooling rate and crystallinity of Ni catalyst were systematically changed to study the mechanism of the precipitation method using the W cap layer. By the optimization of the conditions, wrinkle-free multilayer graphene with D/G ratio of less than 0.1 were successfully obtained directly on a sapphire substrate.

Yamada, J.; Inoue, T.; Nakamura, N.; Kameshima, T.; Yamauchi, K.; Matsuyama, S.; Yabashi, M. X-Ray Single-Grating Interferometry for Wavefront Measurement and Correction of Hard X-Ray Nanofocusing Mirrors. Sensors 2020, 20, 7356. https://doi.org/10.3390/s20247356., X-ray single-grating interferometry was applied to conduct accurate wavefront corrections for hard X-ray nanofocusing mirrors. Systematic errors in the interferometer, originating from a grating, a detector, and alignment errors of the components, were carefully examined. Based on the measured wavefront errors, the mirror shapes were directly corrected using a differential deposition technique. The corrected X-ray focusing mirrors with a numerical aperture of 0.01 attained two-dimensionally diffraction-limited performance. The results of the correction indicate that the uncertainty of the wavefront measurement was less than λ/72 in root-mean-square value.

In situ X-ray diffraction measurement was performed to study the precipitation mechanism of graphene from Ni catalyst with and without Ti capping layer using X-ray beam from a synchrotron radiation facility. The graphene precipitated on the surface of the catalyst in the case without the Ti capping layer while it did at the interface between the catalyst and the sapphire substrate in the case with the Ti capping layer. Each process, such as graphene nucleation and precipitation was successfully monitored even though graphene precipitated under the metal catalyst. The detailed mechanisms for both cases were discussed using the experimental results. Consequently, the crystallization of the catalyst is found to effectively suppress the precipitation at low temperature, which is useful to improve the quality of the precipitated graphene. The adjustment of the amount of the carbons is another important factor to precisely control the precipitation because graphene also precipitates after the carbons saturate the catalyst.

Polystyrene particle-stabilized bubbles were successfully coated with polyaniline overlayers by aqueous chemical oxidative polymerization, and the loading amount of polyaniline to the bubbles could be controlled simply by changing aniline concentration in the polymerization media. Remote motion control of the particle-stabilized bubbles coated by the polyaniline overlayers was realized on a planar air–water surface by light irradiation, due to light-to-heat photothermal property of the polyaniline. A Marangoni flow induced by site-selective light irradiation of the bubble could work as a driving force to move the bubble on the water surface, and the direction and timing of irradiation could control the direction and timing of the motion on demand. Pathlength, velocity, acceleration and force of the bubble motions became longer and larger with an increase of polyaniline loading amount on the bubbles, which was confirmed by numerical analyses. Furthermore, the bubbles were demonstrated to be able to adhere two solid substrates under water after disruption by application of compressive stress.

X-ray full-field microscopy is a promising method for nondestructive observation of opaque materials because it can attain a high resolution and wide field of view without sample scanning. We recently developed hard x-ray objective optics, which are key devices for full-field microscopy, based on total-reflection mirrors with high throughput and achromatic properties. The objective optics consist of two types of advanced Kirkpatrick–Baez mirrors configured as crossed one-dimensional Wolter type I and type III optics. The designed optics possessed magnification factors of 42–45 with a compact camera length of approximately 2 m. The hard x-ray full-field microscope based on this system was tested at the BL29XU beamline at SPring-8. We were able to resolve 100-nm periods (50-nm line widths) of a resolution test chart at a photon energy of 15 keV over 30 h, which demonstrated the remarkable stability of this system. The image quality was preserved over a wide photon energy range from 9 to 15 keV. A periodic dot pattern with dot diameters of 300 nm, formed on a 775-µm-thick Si substrate, was three-dimensionally visualized by computed tomography.

The direct growth of graphene was investigated with precipitating graphene on a GaN template at various temperatures. In the method, a carbon source and catalyst were firstly deposited, and the sample was annealed to precipitate graphene. Tungsten capping layer was deposited on the surface to suppress the graphene precipitating to the sample surface. Consequently, the graphene was precipitated at the interface between the catalyst and the GaN template. After the removal of the catalyst, the graphene was successfully obtained on the GaN template. The Raman D/G ratio of the graphene decreased with increasing the annealing temperature. At 700 °C, fine graphene was obtained on the GaN template while maintaining the flatness and smoothness of the GaN surface. XRD and XPS measurements were also performed to investigate the precipitation of the graphene in detail.

High angular-resolution imagery (~1” or better) together with good off-axis scattering performance (

The mechanism for the precipitation of multilayer graphene was investigated with respect to the use of an Al2O3 barrier layer and Au capping layer. The Al2O3 barrier layer suppresses the dissolution of carbon into the catalyst, especially at low temperature, and assists a decrease in the density of graphene nuclei. On the other hand, the Au capping layer is beneficial to weaken the strong binding between the catalyst and the graphene carbon atoms, and enhances the surface migration of precipitated carbon adatoms. A combination of the Al2O3 barrier layer and Au capping layer is useful for the synthesis of high-quality graphene with large grains. On a sample with both layers annealed for 60 min, the area of 5-layer graphene islands is as large as 10 μm, and covers 60% of the entire surface. The Raman D/G band intensity ratio of 0.024 indicates the precipitated graphene is high quality.

A full-field X-ray microscope utilizing advanced Kirkpatrick–Baez optics, which comprises four concave mirrors, provides high-resolution X-ray images without chromatic aberration. However, a large distance is required between the mirrors and the detector to obtain sufficiently high magnification factor. To achieve reduce this distance, this paper proposes a novel X-ray imaging mirror system consisting of two pairs of concave and convex mirrors, which enables the effective focal length to be decreased by shifting the principal surface. For developing the proposed optics, the mirrors were fabricated with an ion beam figuring system and stitching interferometer, developed by our group, with a peak-to-valley accuracy of ~2 nm. Analysis results indicate that the fabricated mirrors can achieve nearly diffraction-limited imaging performance. We report the mirror fabrication results and the characteristics of the fabricated mirrors.

Taro Sakao, Satoshi Matsuyama, Takumi Goto, Jumpei Yamada, Shuhei Yasuda, Kazuto Yamauchi, Yoshiki Kohmura, Ayumi Kime, Akira Miyake, Tadakazu Maezawa, Hirokazu Hashizume, Yoshinori Suematsu, Noriyuki Narukage, and Shin-nosuke Ishikawa "Development of precision Wolter mirrors for solar x-ray observations", Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860E (23 August 2017); https://doi.org/10.1117/12.2273507.

X-ray spectromicroscopy with a full-field imaging technique is a powerful method for chemical analysis of heterogeneous complex materials with a nano-scale spatial resolution. For imaging optics, an X-ray reflective optical system has excellent capabilities with highly efficient, achromatic, and long-working-distance properties. An advanced Kirkpatrick–Baez geometry that combines four independent mirrors with elliptic and hyperbolic shapes in both horizontal and vertical directions was developed for this purpose, although the complexity of the system has a limited applicable range. Here, we present an optical system consisting of two monolithic imaging mirrors. Elliptic and hyperbolic shapes were formed on a single substrate to achieve both high resolution and sufficient stability. The mirrors were finished with a ~1-nm shape accuracy using elastic emission machining. The performance was tested at SPring-8 with a photon energy of approximately 10 keV. We could clearly resolve 50-nm features in a Siemens star without chromatic aberration and with high stability over 20 h. We applied this system to X-ray absorption fine structure spectromicroscopy and identified elements and chemical states in specimens of zinc and tungsten micron-size particles.

Graphene was directly grown on r-plane (1-102), c-plane (0001), and a-plane (11-20) sapphires by low pressure chemical vapor deposition without the use of a metal catalyst. The growth temperature was systematically changed between 1090 and 1210 °C to investigate the effects of the crystal orientation of sapphire on the graphene growth. It was found that the growth rate of graphene on r-plane sapphire was very fast compared to that of the samples grown on other orientations. The surface catalytic effect of r-plane sapphire promotes the smooth and flat growth of single-layer graphene. The surface of the r-plane sapphire was kept smooth even at a high temperature of 1210 °C because a quick coverage of graphene protects the surface of the sapphire from thermal decomposition and roughening.

A novel full-field X-ray fluorescence microscope based on total-reflection advanced Kirkpatrick-Baez mirror optics was developed. The total-reflection imaging mirror optics arrangement, with four reflections, has the advantage of being able to function both as a powerful low-pass energy filter, completely rejecting incident excitation X-rays, and as an achromatic optical imaging system. Isolated X-ray fluorescence signals can be imaged, avoiding imaging-detector saturation, with low background noise. A prototype fluorescence microscope constructed at SPring-8 demonstrated the capability to simultaneously image elemental distributions using various X-ray fluorescence signals (Ni, Cu, Zn, Ge, and Bi). A half-period spatial resolution of ~0.5-1 µm (1000-500 LP/mm) was achieved, owing to the achromaticity of the imaging mirrors and the photon-counting scheme of the CCD camera used for fluorescence detection.

In order to advance the mass production of graphene devices, it is beneficial to avoid the difficulty graphene transfer process. Direct precipitation of graphene using a tungsten capping layer is convenient for this purpose, and is quite simple and compatible with conventional semiconductor fabrication processes. In this study, multilayer graphene was directly precipitated on a wafer of GaN-based blue LEDs to form a transparent electrode. The fabricated LED exhibited superior I–V characteristics and emitted blue luminescence around the probe of the electrode.

We demonstrated that the combination of a hyperbolic convex and elliptical concave mirrors works as a compact reflective X-ray imaging system with a short optical focal length and large magnification factor. We performed an experiment to form a one-dimensional demagnified image with a demagnification factor of 321 within an approximately 2-m-long optical setup at an X-ray energy of 10 keV. The results showed that this imaging optics system is capable of providing a resolution of ~40 nm. From wavefront analysis, it was confirmed that the optics possessed a wide field-of-view with a significant reduction of comatic aberration.

We propose the use of two pairs of concave-convex mirrors as imaging optics for the compact full-field x-ray microscope with high resolution and magnification factors. The optics consists of two pairs of hyperbolic convex and elliptical concave mirrors with the principal surface near the object, consequently enabling the focal length to be 10 times shorter than conventional advanced Kirkpatrick-Baez mirror optics. This paper describes characteristics of the optics calculated by ray-tracing and wave-optical simulators. The expected spatial resolution is approximately 40 nm with a wide field of view of more than 10 μm and a total length of about 2 m, which may lead to the possibility of laboratory-sized, achromatic, and high-resolution full-field x-ray microscopes.