Universal handheld micropipette
The handheld micropipette is the most ubiquitous instrument for precision handling of microliter-milliliter liquid volumes, which is an essential capability in biology and chemistry laboratories. The range of one pipette is typically adjustable up to 10-fold its minimum volume, requiring the use and maintenance of multiple pipettes for liquid handling across larger ranges. Here we propose a design for a single handheld pipette adjustable from 0.1μl to 1000μl (i.e., 104-fold) which spans the range of an entire suite of current commercial pipettes. This is accomplished by placing anelastic diaphragm between the existing pi...
Source: Review of Scientific Instruments - November 14, 2016 Category: Physics Authors: Justin Beroz and A. John Hart Source Type: research
Fabrication of sharp atomic force microscope probes using in situ local electric field induced deposition under ambient conditions
We demonstrate a simple method to significantly improve the sharpness of standardsilicon probes for anatomic force microscope or to repair a damaged probe. The method is based on creating and maintaining a strong, spatially localizedelectric field in the air gap between the probe tip and thesurface of conductive sample. Under these conditions, nanostructure growth takes place on both the sample and the tip. The most likely mechanism is the decomposition of atmosphericadsorbate with subsequent deposition ofcarbon structures. This makes it possible to grow a spike of a few hundred nanometers in length on the tip. We further ...
Source: Review of Scientific Instruments - November 14, 2016 Category: Physics Authors: Alexei Temiryazev, Sergey I. Bozhko, A. Edward Robinson and Marina Temiryazeva Source Type: research
Multicharged carbon ion generation from laser plasma
Carbon ions generated byablation of acarbon target using anNd:YAG laser pulse (wavelength λ = 1064 nm, pulse width τ = 7 ns, and laser fluence of 10-110 J cm−2) are characterized.Time-of-flight analyzer, a three-mesh retarding field analyzer, and an electrostatic ion energy analyzer are used to study the charge and energy ofcarbon ions generated bylaser ablation. The dependencies of the ion signal on the laser fluence, laser focal point position relative to target surface, and the acceleration voltage are described. Up to C4+ ions are observed. When no acceleration voltage is applied between thecarbon target and a grou...
Source: Review of Scientific Instruments - November 14, 2016 Category: Physics Authors: Oguzhan Balki and Hani E. Elsayed-Ali Source Type: research
Multi-energy SXR cameras for magnetically confined fusion plasmas (invited)
A compact multi-energysoft x-raycamera has been developed for time, energy and space-resolvedmeasurements of the soft-x-rayemissivity in magnetically confined fusion plasmas. Multi-energysoft x-rayimaging provides a unique opportunity formeasuring, simultaneously, a variety of important plasma properties (Te,nZ, ΔZeff, andne,fast). The electrontemperature can be obtained by modeling the slope of the continuum radiation from ratios of the available brightness and inverted radialemissivity profiles over multiple energy ranges. Impurity densitymeasurements are also possible using the line-emission from medium- to high-Z impu...
Source: Review of Scientific Instruments - November 14, 2016 Category: Physics Authors: L. F. Delgado-Aparicio, J. Maddox, N. Pablant, K. Hill, M. Bitter, J. E. Rice, R. Granetz, A. Hubbard, J. Irby, M. Greenwald, E. Marmar, K. Tritz, D. Stutman, B. Stratton and P. Efthimion Source Type: research
Laser pumped 4He magnetometer with light shift suppression
We report a laser-pumped4He atomic magnetometer with light shift suppression through the atomic sensor itself. A linearly polarized light is used to optically align the4He metastable atoms and we monitor themagneto-optical double resonance (MODR) signals produced by the left- and right-circularly orthogonal components. It is shown that light shift leads to the atomic alignment to orientation conversioneffect, and thus, the difference between the two MODR signals. One of these two MODR signals is locked at the Larmor frequency and is used tomeasure the ambientmagnetic field, while the differential signal is, simultaneously,...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Zaisheng Lin, He Wang, Xiang Peng, Teng Wu and Hong Guo Source Type: research
Low magnetic Johnson noise electric field plates for precision measurement
We describe a parallel pair of high voltageelectric field plates designed and constructed to minimise magneticJohnson noise. They are formed by laminating glass substrates with a commercially available polyimide (Kapton) tape, covered with a thingold film. Tested in vacuum, the outgassing rate is less than 5 × 10−5 mbar l/s. The plates have been operated atelectric fields up to 8.3 kV/cm, when theleakage current is at most a few hundred pA. The design is discussed in the context of a molecular spin precession experiment tomeasure the permanent electric dipole moment of the electron. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: I. M. Rabey, J. A. Devlin, E. A. Hinds and B. E. Sauer Source Type: research
Calibration of excitation function measurement based on corona cage test results
Corona cage approaches are crucial for research on thecorona characteristics ofconductors.Calibration is an indispensable task for determining excitation functions, which are used to predictcorona performance of long transmission lines through extrapolation from measurements of short lines incorona cages. In this paper, the amplification factor G is calculated through a frequently adopted method, propagation analysis of high-frequencycoronacurrent along a short line. Another convenientcalibration method, based on distributed parameter equivalent circuits, is established. The results for G obtained through propagation analy...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Lei Lan, Xiaoyue Chen, Xishan Wen, Wei Li and Guozhou Xiao Source Type: research
Development and characterization of an interferometer for calorimeter-based absorbed dose to water measurements in a medical linear accelerator
The quantity of relevance for external beam radiotherapy is absorbeddose to water (ADW). Aninterferometer was built, characterized, and tested to measure ADW within thedose range of interest for external beam radiotherapy using the temperature dependence of therefractive index of water. Theinterferometer was used to measure radiation-induced phase shifts of alaser beam passing through a (10 × 10 × 10) cm3 water-filled glass phantom,irradiated with a 6 MV photon beam from a medicallinear accelerator. Thefield size was (7 × 7) cm2 and thedose was measured at a depth of 5 cm in the water phantom. The intensity of the inter...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Everardo Flores-Martinez, Martha J. Malin and Larry A. DeWerd Source Type: research
A new setup for high resolution fast X-ray reflectivity data acquisition
A new method for fastx-rayreflectivitydata acquisition is presented. The method is based on a fast rotating, slightly tilted sample reflecting to a stationary mountedposition sensitive detector and it allows for measurements ofreflectivity curves in a quarter of a second. The resolution in q-space mainly depends on the beam properties and the pixel size of thedetector. Maximum qz-value of 1 Å−1 can be achieved. The time-temperature dependingstructure changes of poly(N-isopropylacrylamide)thin films were investigatedin situ by applying the fast-reflectivity setup. The results are presented in this paper as illustration o...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Milena Lippmann, Adeline Buffet, Kathrin Pflaum, Anita Ehnes, Anca Ciobanu and Oliver H. Seeck Source Type: research
High-precision measurement of magnetic penetration depth in superconducting films
The magnetic penetration depth ( λ) in thin superconductingfilms is usually measured by the mutualinductance technique. The accuracy of this method has been limited by uncertainties in the geometry of the solenoids and in thefilm position and thickness, by parasitic coupling between the coils, etc. Here, we present several improvements in the apparatus and the method. To ensure the precise thickness of the superconducting layer, we engineer thefilms at atomic level using atomic-layer-by-layer molecular beam epitaxy. In this way, we also eliminate secondary-phase precipitates, grain boundaries, and pinholes that are common...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: X. He, A. Gozar, R. Sundling and I. Bo žović Source Type: research
A scanning Hall probe microscope for high resolution, large area, variable height magnetic field imaging
We present a scanning Hall probemicroscope operating in ambient conditions. One of the unique features of thismicroscope is the use of the same stepper motors for both sample positioning as well as scanning, which makes it possible to have a large scan range (few mm) in thex andy directions, with a scan resolution of 0.1 μm. Protocols have been implemented to enable scanning at different heights from the sample surface. Thez range is 35 mm. Microstructured Hall probes of size 1-5 μm have been developed. A minimum probe-sample distance (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Gorky Shaw, R. B. G. Kramer, N. M. Dempsey and K. Hasselbach Source Type: research
Development of multi-frequency ESR/EDMR system using a rectangular cavity equipped with waveguide window
A straightforward method for a variable frequency electron spinresonance/electrically detected magneticresonance (ESR/EDMR)spectroscopy using a C-bandmicrowavecavity equipped with waveguide windows is presented. The method enables us to perform quasi-continuous multipleresonance frequency (MF-ESR/EDMR) experiments for electronic devices. The C-bandmicrowave circuitry was selected because of larger available sample volume than that for conventional X-band one. All themeasurements were performed using a combined sample of 2,2-diphenyl-1-picrylhydrazyl/ pn-junction Si diode. The present simple MF-ESR/EDMR method will be usefu...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Kunito Fukuda and Naoki Asakawa Source Type: research
Experimental study on the fluorescence spectrum in the near-ultraviolet and visible regions of a carbon dioxide gas Cerenkov medium
We investigated the faintfluorescencespectrum ofcarbon dioxide in the near-ultraviolet and visible regions using an intense relativistic electron beam accelerator with an energy of 0.2 –0.3 MeV. Monte Carlo simulations were carried out in advance to maximize the signal-to-noise ratio and a self-normalization pulse experimental layout was designed to overcome the shot-to-shot fluctuations in different pulses of the accelerator. Ultimately, the relative proportion sequences in the near-ultraviolet and visible regions of acarbon dioxidefluorescencespectrum were successfully obtained for the first time. The result shows that...
Source: Review of Scientific Instruments - November 11, 2016 Category: Physics Authors: Xingyin Guan, Huasi Hu, Zhaohui Song and Hetong Han Source Type: research
Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer
We present the optical design of the Centurionsoft X-ray resonant inelastic X-ray scattering (RIXS)spectrometer to be located on the SIX beamline at NSLS-II. Thespectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112 ° using a custom triple rotating flange. We have analyzed several possiblespectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwoodspectrometer design, with an additional planemirror to maintain a fixed direction for th...
Source: Review of Scientific Instruments - November 10, 2016 Category: Physics Authors: Joseph Dvorak, Ignace Jarrige, Valentina Bisogni, Scott Coburn and William Leonhardt Source Type: research
Non-magnetic flexible heaters for spin-exchange optical pumping of 3He and other applications
Spin polarized3He gas is currently widely used in various scientific fields and in medical diagnosis applications. The spinpolarization of3He nuclei can be achieved by spin-exchangeoptical pumping (SEOP). In SEOP, the3He gas is enclosed in a glass cell together withalkali metals and is then heated to maintain thealkali metal vapor pressures at the appropriate levels. However, polarized3He gas is highly sensitive to any inhomogeneity in itsmagnetic field, and any small field gradients caused by theheaters may cause degradation of the3Hepolarization. To overcome this conflict between the heating process and themagnetic field...
Source: Review of Scientific Instruments - November 10, 2016 Category: Physics Authors: T. Ino, H. Hayashida, H. Kira, T. Oku and K. Sakai Source Type: research
