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Review of Scientific Instruments

Matteo Roiaz, Verena Pramhaas, Xia Li, Christoph Rameshan, Günther Rupprechter
A new custom-designed ultrahigh vacuum (UHV) chamber coupled to a UHV and atmospheric-pressure-compatible spectroscopic and catalytic reaction cell is described, which allows us to perform IR-vis sum frequency generation (SFG) vibrational spectroscopy during catalytic (kinetic) measurements. SFG spectroscopy is an exceptional tool to study vibrational properties of surface adsorbates under operando conditions, close to those of technical catalysis. This versatile setup allows performing surface science, SFG spectroscopy, catalysis, and electrochemical investigations on model systems, including single crystals, thin films, and deposited metal nanoparticles, under well-controlled conditions of gas composition, pressure, temperature, and potential...
April 2018: Review of Scientific Instruments
Wei Huang, Zhean Li, Chunkai Xu, Jian Liu, Chunye Xu, Xiangjun Chen
We report a novel microelectrode-shielding tip (ME tip) for scanning probe electron energy spectroscopy (SPEES). The shielding effect of this tip is studied through comparing the detection efficiency with the normal tip by both experiment and simulation. The results show that the backscattering count rate detected by the SPEES instrument using the normal tip begins to decrease as the tip approaches to the sample surface within 21 μm, while that using the ME tip only starts to drop off within 1 μm. This indicates that the electron energy spectra can be measured with the ME tip at a much closer tip-sample distance...
April 2018: Review of Scientific Instruments
Eric L Shirley, Mitchell Furst, Uwe Arp
We have developed a new method for the exact calculation of synchrotron radiation for the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility, SURF III. Instead of using the Schwinger formula, which is only an approximation, we develop formulae based on Graf's addition theorem for Bessel functions and accurate asymptotic expansions for Hankel functions and Bessel functions. By measuring the radiation intensity profile at two distances from the storage ring, we also confirm an apparent vertical emittance that is consistent with the vertical betatron oscillations that are intentionally introduced to extend beam lifetime by spreading the electron beam spatially...
April 2018: Review of Scientific Instruments
Sze Cheung Lau, Hoi Chun Chiu, Luwei Zhao, Teng Zhao, M M T Loy, Shengwang Du
We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution...
April 2018: Review of Scientific Instruments
Youfeng Zhang, Yunje Oh, Douglas Stauffer, Andreas A Polycarpou
We present a highly sensitive force-displacement transducer capable of performing ultra-shallow nanoindentation and adhesion measurements. The transducer utilizes electrostatic actuation and capacitive sensing combined with microelectromechanical fabrication technologies. Air indentation experiments report a root-mean-square (RMS) force resolution of 1.8 nN and an RMS displacement resolution of 0.019 nm. Nanoindentation experiments on a standard fused quartz sample report a practical RMS force resolution of 5 nN and an RMS displacement resolution of 0...
April 2018: Review of Scientific Instruments
C Wang, J Hu, F Wang, J Jiang, Z Z Zhang, Y Yang, J X Ding, H C Jiang, Y M Wang, H Y Wei
Fires resulting from titanium combustion are complex and violent processes which can instantly burn a titanium alloy once ignited. The occurrence of titanium combustion is a disaster for aircraft. Accurate measurement of the ignition temperature of titanium alloys is of significance in preventing such fires and in investigating combustion-resistance properties. In this study, monochromatic temperature and emissivity measurement methods based on reflectivity detection were used to determine the ignition temperature of a titanium alloy...
April 2018: Review of Scientific Instruments
Shenggang Liu, Jiabo Li, Jun Li, Tao Xue, Tianjiong Tao, Heli Ma, Xiang Wang, Jidong Weng, Zeren Li
A novel method based on signal superimposing has been presented to simultaneously measure the dynamic emissivity and the radiance of a shocked sample/window interface in the near-infrared wavelength. In this method, we have used three rectangle laser pulses to illuminate the sample/window interface via an integrating sphere and expect that the reflected laser pulses from the sample/window interface can be superimposed on its thermal radiation at the shocked steady state by time precision synchronization. In the two proving trials, the second laser pulse reflected from the Al/LiF interface has been successfully superimposed on its thermal radiation despite large flyer velocity uncertainty...
April 2018: Review of Scientific Instruments
Jong-Ahn Kim, Jae Wan Kim, Chu-Shik Kang, Jonghan Jin
This Note presents a new absolute X-Y-Θ position sensor for measuring planar motion of a precision multi-axis stage system. By analyzing the rotated image of a two-dimensional phase-encoded binary scale (2D), the absolute 2D position values at two separated points were obtained and the absolute X-Y-Θ position could be calculated combining these values. The sensor head was constructed using a board-level camera, a light-emitting diode light source, an imaging lens, and a cube beam-splitter. To obtain the uniform intensity profiles from the vignette scale image, we selected the averaging directions deliberately, and higher resolution in the angle measurement could be achieved by increasing the allowable offset size...
April 2018: Review of Scientific Instruments
Guenther Glatz, Alexandre Lapene, Louis M Castanier, Anthony R Kovscek
A conventional high-pressure/high-temperature experimental apparatus for combined geomechanical and flow-through testing of rocks is not X-ray compatible. Additionally, current X-ray transparent systems for computed tomography (CT) of cm-sized samples are limited to design temperatures below 180 °C. We describe a novel, high-temperature (>400 °C), high-pressure (>2000 psi/>13.8 MPa confining, >10 000 psi/>68.9 MPa vertical load) triaxial core holder suitable for X-ray CT scanning. The new triaxial system permits time-lapse imaging to capture the role of effective stress on fluid distribution and porous medium mechanics...
April 2018: Review of Scientific Instruments
Karolina Orłowska, Michał Świątkowski, Piotr Kunicki, Teodor Gotszalk
In the present paper, we describe a high sensitivity intensity fibre-optic displacement sensor with tens of picometre resolution combined with a sub-picometre resolution interferometric calibration system. Both integrated components form the so-called "2 in one ferrule" system 2iOF. The design and construction of the presented device depend on integrating two sensors' systems within one fibre-optic measuring head, which allows performing in situ calibration process with no additional time-consuming adjustment procedure...
April 2018: Review of Scientific Instruments
Pablo A Fernández Garrillo, Benjamin Grévin, Nicolas Chevalier, Łukasz Borowik
We propose and demonstrate the implementation of an alternative work function tip calibration procedure for Kelvin probe force microscopy under ultrahigh vacuum, using monocrystalline metallic materials with known crystallographic orientation as reference samples, instead of the often used highly oriented pyrolytic graphite calibration sample. The implementation of this protocol allows the acquisition of absolute and reproducible work function values, with an improved uncertainty with respect to unprepared highly oriented pyrolytic graphite-based protocols...
April 2018: Review of Scientific Instruments
Noboru Watanabe, Tsukasa Hirayama, So Yamada, Masahiko Takahashi
We report details of an electron-ion coincidence apparatus, which has been developed for molecular-frame electron energy loss spectroscopy studies. The apparatus is mainly composed of a pulsed electron gun, an energy-dispersive electron spectrometer, and an ion momentum imaging spectrometer. Molecular-orientation dependence of the high-energy electron scattering cross section can be examined by conducting measurements of vector correlation between the momenta of the scattered electron and fragment ion. Background due to false coincidences is significantly reduced by introducing a pulsed electron beam and pulsing scheme of ion extraction...
April 2018: Review of Scientific Instruments
H Singh, D Donetsky, J Liu, K Attenkofer, B Cheng, J R Trelewicz, I Lubomirsky, E Stavitski, A I Frenkel
We report the development, testing, and demonstration of a setup for modulation excitation spectroscopy experiments at the Inner Shell Spectroscopy beamline of National Synchrotron Light Source - II. A computer algorithm and dedicated software were developed for asynchronous data processing and analysis. We demonstrate the reconstruction of X-ray absorption spectra for different time points within the modulation pulse using a model system. This setup and the software are intended for a broad range of functional materials which exhibit structural and/or electronic responses to the external stimulation, such as catalysts, energy and battery materials, and electromechanical devices...
April 2018: Review of Scientific Instruments
Takato Inoue, Satoshi Matsuyama, Shogo Kawai, Hirokatsu Yumoto, Yuichi Inubushi, Taito Osaka, Ichiro Inoue, Takahisa Koyama, Kensuke Tono, Haruhiko Ohashi, Makina Yabashi, Tetsuya Ishikawa, Kazuto Yamauchi
In this study, the systematic errors of an X-ray single-grating interferometer based on the Talbot effect were investigated in detail. Non-negligible systematic errors induced by an X-ray camera were identified and a method to eliminate the systematic error was proposed. Systematic-error-free measurements of the wavefront error produced by multilayer focusing mirrors with large numerical apertures were demonstrated at the SPring-8 Angstrom Compact free electron LAser. Consequently, wavefront aberration obtained with two different cameras was found to be consistent with an accuracy better than λ/12...
April 2018: Review of Scientific Instruments
Paul Roberts, Georgia A Pilkington, Yumo Wang, Joelle Frechette
We present the multifunctional force microscope (MFM), a normal and lateral force-measuring instrument with in situ imaging. In the MFM, forces are calculated from the normal and lateral deflection of a cantilever as measured via fiber optic sensors. The motion of the cantilever is controlled normally by a linear micro-translation stage and a piezoelectric actuator, while the lateral motion of the sample is controlled by another linear micro-translation stage. The micro-translation stages allow for travel distances that span 25 mm with a minimum step size of 50 nm, while the piezo has a minimum step size of 0...
April 2018: Review of Scientific Instruments
M Holler, J Raabe, A Diaz, M Guizar-Sicairos, R Wepf, M Odstrcil, F R Shaik, V Panneels, A Menzel, B Sarafimov, S Maag, X Wang, V Thominet, H Walther, T Lachat, M Vitins, O Bunk
For many scientific questions gaining three-dimensional insight into a specimen can provide valuable information. We here present an instrument called "tOMography Nano crYo (OMNY)," dedicated to high resolution 3D scanning x-ray microscopy at cryogenic conditions via hard X-ray ptychography. Ptychography is a lens-less imaging method requiring accurate sample positioning. In OMNY, this in achieved via dedicated laser interferometry and closed-loop position control reaching sub-10 nm positioning accuracy...
April 2018: Review of Scientific Instruments
A Q Kuang, D Brunner, B LaBombard, R Leccacorvi, R Vieira
An array of flush-mounted and toroidally elongated Langmuir probes (henceforth called rail probes) have been specifically designed for the Alcator C-Mod's vertical target plate divertor and operated over multiple campaigns. The "flush" geometry enables the tungsten electrodes to survive high heat flux conditions in which traditional "proud" tungsten electrodes suffer damage from melting. The toroidally elongated rail-like geometry reduces the influence of sheath expansion, which is an important effect to consider in the design and interpretation of flush-mounted Langmuir probes...
April 2018: Review of Scientific Instruments
K Fehre, D Trojanowskaja, J Gatzke, M Kunitski, F Trinter, S Zeller, L Ph H Schmidt, J Stohner, R Berger, A Czasch, O Jagutzki, T Jahnke, R Dörner, M S Schöffler
Modern momentum imaging techniques allow for the investigation of complex molecules in the gas phase by detection of several fragment ions in coincidence. For these studies, it is of great importance that the single-particle detection efficiency ε is as high as possible, as the overall efficiency scales with εn , i.e., the power of the number of detected particles. Here we present measured absolute detection efficiencies for protons of several micro-channel plates (MCPs), including efficiency enhanced "funnel MCPs...
April 2018: Review of Scientific Instruments
Enzheng Zhang, Benyong Chen, Hao Zheng, Xueying Teng, Liping Yan
A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7...
April 2018: Review of Scientific Instruments
J M O'Reilly, P Stamenov
Here two new techniques for the detection of broadband (100 MHz-20 GHz) ferromagnetic resonance (FMR)/ferrimagnetic resonance in single and poly-crystalline materials, which rely on SQUID-based gradiometry detection of small changes in the magnetisation, are developed. In the first method, small changes in the along-the-applied-field projection of the coupled magnetic moment (Δmz ) are detected as the material is driven into resonance. Absolute measurement of the longitudinal component of the magnetisation and the resonance induced lowering of this moment makes estimation of the precession cone angle accessible, which is typically difficult to extract using conventional cavity or stripline based detection methods...
April 2018: Review of Scientific Instruments
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