RSI Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter UniPHY Group iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Jul 2009

Volume 80, Issue 7, Articles (07xxxx)

Issue Cover Spotlight Figure

Rev. Sci. Instrum. 80, 071301 (2009); http://dx.doi.org/10.1063/1.3174431 (9 pages)

Charles M. Falco

Near infra-red light (700-1100 nm) penetrates many pigments to depths of several tens of micro-meters. Since the reds and yellows used for this table covering happen to be nearly transparent to these wavelengths, high resolution imaging in the IR reveals additional marks made by the artist under the surface.

Enlarge Image | Read More
Page 1 of 3 Pages Next Page | Jump to Page
back to top
RSS Feeds

Invited Article: High resolution digital camera for infrared reflectography

Charles M. Falco

Rev. Sci. Instrum. 80, 071301 (2009); http://dx.doi.org/10.1063/1.3174431 (9 pages) | Cited 1 time

Online Publication Date: 15 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper describes the characteristics of a high resolution infrared (IR) imaging system operating over the wavelength range of 830–1100 nm, based on a modified 8 Mpixels commercial digital camera, with which nonspecialists can obtain IR reflectograms of works of art in situ in a museum environment. The relevant imaging properties of sensitivity, resolution, noise, and contrast are characterized and the capabilities of this system are illustrated with an example that has revealed important new information about the working practices of a 16th century artist.
Show PACS
42.79.Pw Imaging detectors and sensors
42.30.Va Image forming and processing
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
back to top
RSS Feeds

Design and development of a portable gamma radiation monitor

M. Munir, N. Ahmad, S. Sohail, R. A. Naveed, M. Q. Rafiq, and M. Khalid

Rev. Sci. Instrum. 80, 073101 (2009); http://dx.doi.org/10.1063/1.3160292 (6 pages)

Online Publication Date: 7 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A portable gamma radiation monitor has been designed and developed. The monitor can be used effectively in the dose range from 0.07 to 500 mGy/h due to gamma rays of energy greater than 65 keV. The monitor overestimated radiation doses and the uncertainty in the measured dose rate has been found to be ≤ 30%. The response of the monitor can be considered isotropic within an acceptable error of ±30%. Provision has also been added to use the monitor as an installed radiation monitor. In installed mode, it can be operated from a remote location up to 1 km and the timing history can be stored on a personal computer.
Show PACS
87.55.N- Radiation monitoring, control, and safety
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors
87.53.Bn Dosimetry/exposure assessment

Terahertz-range free-electron laser electron spin resonance spectroscopy: Techniques and applications in high magnetic fields

S. A. Zvyagin, M. Ozerov, E. Čižmár, D. Kamenskyi, S. Zherlitsyn, T. Herrmannsdörfer, J. Wosnitza, R. Wünsch, and W. Seidel

Rev. Sci. Instrum. 80, 073102 (2009); http://dx.doi.org/10.1063/1.3155509 (7 pages) | Cited 3 times

Online Publication Date: 8 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The successful use of picosecond-pulse free-electron-laser (FEL) radiation for the continuous-wave terahertz-range electron spin resonance (ESR) spectroscopy has been demonstrated. The combination of two linac-based FELs (covering the wavelength range of 4–250 μm) with pulsed magnetic fields up to 70 T allows for multifrequency ESR spectroscopy in a frequency range of 1.2–75 THz with a spectral resolution better than 1%. The performance of the spectrometer is illustrated with ESR spectra obtained in the 2,2-diphenyl-1-picrylhydrazyl and the low-dimensional organic material (C6H9N2)CuCl3.
Show PACS
07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques
76.30.-v Electron paramagnetic resonance and relaxation

Realization and performance evaluation of high speed autofocusing for direct laser lithography

Hyug-Gyo Rhee, Dong-Ik Kim, and Yun-Woo Lee

Rev. Sci. Instrum. 80, 073103 (2009); http://dx.doi.org/10.1063/1.3176468 (5 pages) | Cited 3 times

Online Publication Date: 15 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The autofocusing is one of the important parts in the automated vision inspection or measurement using optical microscopes. Moreover, laser micromachining or laser lithography requires a high speed and precision autofocusing. In this paper, we propose and realize an autofocusing system using two cylindrical lenses, which is the enhanced version of the previous astigmatism method. It shows very good performances, especially very high speed and the largest range in comparison with the previous astigmatic methods. The performance of our autofocusing system was evaluated by tracing the linear stage whose position was monitored by a commercial laser interferometer. Then we applied the autofocusing to the direct laser lithographic system, and successfully fabricated circular symmetry patterns on a 300 mm diameter surface with the resolution of less than 1 μm within the defocusing range of ±50 μm. The speed of the autofocusing was 150 Hz.
Show PACS
06.60.Mr Testing and inspecting procedures

Broadband sensitive pump-probe setup for ultrafast optical switching of photonic nanostructures and semiconductors

Tijmen G. Euser, Philip J. Harding, and Willem L. Vos

Rev. Sci. Instrum. 80, 073104 (2009); http://dx.doi.org/10.1063/1.3156049 (9 pages) | Cited 3 times

Online Publication Date: 15 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe an ultrafast time resolved pump-probe spectroscopy setup aimed at studying the switching of nanophotonic structures. Both femtosecond pump and probe pulses can be independently tuned over broad frequency range between 3850 and 21 050 cm−1. A broad pump scan range allows a large optical penetration depth, while a broad probe scan range is crucial to study strongly photonic crystals. A new data acquisition method allows for sensitive pump-probe measurements, and corrects for fluctuations in probe intensity and pump stray light. We observe a tenfold improvement of the precision of the setup compared to laser fluctuations, allowing a measurement accuracy of better than ΔR = 0.07% in a 1 s measurement time. Demonstrations of the improved technique are presented for a bulk Si wafer, a three-dimensional Si inverse opal photonic bandgap crystal, and z-scan measurements of the two-photon absorption coefficient of Si, GaAs, and the three-photon absorption coefficient of GaP in the infrared wavelength range.
Show PACS
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.65.Pc Optical bistability, multistability, and switching, including local field effects
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
42.70.Qs Photonic bandgap materials

A hexapole magnetic guide for neutral atomic beams

J. P. Beardmore, A. J. Palmer, K. C. Kuiper, and R. T. Sang

Rev. Sci. Instrum. 80, 073105 (2009); http://dx.doi.org/10.1063/1.3176470 (5 pages) | Cited 2 times

Online Publication Date: 17 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this paper we present a multiple element magnetic device to guide atoms using a spatially inhomogeneous magnetic field formed by a series of permanent hexapole magnets. The operation of the device is demonstrated using an enhanced beam of neon atoms in the 3P2 metastable state. These atoms are guided around a bend of 30° from their original path. A flux of 4.35×109±2×107 atoms s−1 was measured after the device yielding a transmission efficiency of approximately 9% of the input flux. Simulations of the center of mass motion of the atoms through the magnetic guide have been performed giving reasonable agreement with the experimental results.
Show PACS
37.20.+j Atomic and molecular beam sources and techniques
32.30.-r Atomic spectra

Optical fiber-based single-shot picosecond transient absorption spectroscopy

Andrew R. Cook and Yuzhen Shen

Rev. Sci. Instrum. 80, 073106 (2009); http://dx.doi.org/10.1063/1.3156048 (7 pages) | Cited 3 times

Online Publication Date: 17 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving ∼ 15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into a sample where it is overlapped with an electron pulse or laser excitation pulse, followed by imaging onto a charge coupled device (CCD) detector where the intensity of light from each fiber is measured simultaneously. Application to both ultrafast pump-probe spectroscopy and pulse radiolysis is demonstrated. For pulse radiolysis, the prototype bundle provides the ability to collect data with a time resolution limited only by the electron pulse width of 7–10 ps, over a total single-shot time window of ∼ 1.5 ns. Tunable probe light is obtained from a titanium-sapphire laser and an optical parametric amplifier. Corrections are made to remove the fiber-to-fiber variations in signal magnitude due to the spatial overlap of the electron beam and probe image. High quality data can be collected over most of the sensitivity range of the CCD camera detectors. The single-shot instrument is valuable for measurement of samples that are only available in very limited quantities, are too viscous to flow, or are rigid. It is therefore excellent in applications, such as picosecond pulse radiolysis, where the thousands of pulses per kinetic trace typical in classical pump-probe experiments can damage the sample before useful results could be obtained.
Show PACS
42.81.Wg Other fiber-optical devices
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.-e Optical elements, devices, and systems
42.79.Pw Imaging detectors and sensors
42.65.Lm Parametric down conversion and production of entangled photons

Submicrometer resolution far field high sensitivity Kerr microscopy for in-plane magnetization detection

C. H. Wang and Z. Yang

Rev. Sci. Instrum. 80, 073107 (2009); http://dx.doi.org/10.1063/1.3183496 (4 pages) | Cited 2 times

Online Publication Date: 22 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report that a far field magneto-optical system designed for detecting the off-plane magnetization in polar configuration can also detect the in-plane magnetization, while preserving the high sensitivity by using symmetric illumination and photoelastic modulation, even though the optical axis of the system is vertical to the sample surface. The spatial resolution can reach 500 nm at 514 nm in wavelength. The in-plane sensitivity can be eliminated by using an aperture to remove the off-axis obliquely incident light generated by the high numerical aperture objective lens that focuses the laser beam onto the sample surface.
Show PACS
78.20.Ls Magneto-optical effects
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
75.60.Ch Domain walls and domain structure
72.25.-b Spin polarized transport

A versatile ultrastable platform for optical multidimensional Fourier-transform spectroscopy

A. D. Bristow, D. Karaiskaj, X. Dai, T. Zhang, C. Carlsson, K. R. Hagen, R. Jimenez, and S. T. Cundiff

Rev. Sci. Instrum. 80, 073108 (2009); http://dx.doi.org/10.1063/1.3184103 (8 pages) | Cited 9 times

Online Publication Date: 28 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The JILA multidimensional optical nonlinear spectrometer (JILA-MONSTR) is a robust, ultrastable platform consisting of nested and folded Michelson interferometers that can be actively phase stabilized. This platform generates a square of identical laser pulses that can be adjusted to have arbitrary time delay between them while maintaining phase stability. The JILA-MONSTR provides output pulses for nonlinear excitation of materials and phase-stabilized reference pulses for heterodyne detection of the induced signal. This arrangement is ideal for performing coherent optical experiments, such as multidimensional Fourier-transform spectroscopy, which records the phase of the nonlinear signal as a function of the time delay between several of the excitation pulses. The resulting multidimensional spectrum is obtained from a Fourier transform. This spectrum can resolve, separate, and isolate coherent contributions to the light-matter interactions associated with electronic excitation at optical frequencies. To show the versatility of the JILA-MONSTR, several demonstrations of two-dimensional Fourier-transform spectroscopy are presented, including an example of a phase-cycling scheme that reduces noise. Also shown is a spectrum that accesses two-quantum coherences, where all excitation pulses require phase locking for detection of the signal.
Show PACS
07.60.Rd Visible and ultraviolet spectrometers
07.60.Ly Interferometers

Windowed high-order ambiguity function method for fringe analysis

Sai Siva Gorthi and Pramod Rastogi

Rev. Sci. Instrum. 80, 073109 (2009); http://dx.doi.org/10.1063/1.3186646 (5 pages) | Cited 3 times

Online Publication Date: 29 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper introduces a windowed high-order ambiguity function (WHAF) method for the demodulation of fringe patterns recorded in holographic interferometry. It first obtains the analytic signal of the fringe pattern and models it as a piecewise polynomial phase signal. A parametric estimation procedure based on HAF is then employed to calculate the polynomial coefficients of the phase over each window of the segmented analytic signal. A salient feature of the proposed method is that it provides an accurate and direct estimation of the unwrapped phase distribution from a single fringe pattern, even when the pattern’s phase is rapidly varying. WHAF’s application to both digital and classical holographic interferometry is demonstrated by simulation and experimental results.
Show PACS
42.30.Va Image forming and processing
42.30.Wb Image reconstruction; tomography
42.40.Kw Holographic interferometry; other holographic techniques

Fast-switching system for injection seeding of a high-power Ti:sapphire laser

Hamid R. Khalesifard, Andreas Fix, Gerhard Ehret, Max Schiller, and Volker Wulfmeyer

Rev. Sci. Instrum. 80, 073110 (2009); http://dx.doi.org/10.1063/1.3184011 (5 pages) | Cited 1 time

Online Publication Date: 31 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A high frequency switching and tunable seed laser system has been designed and constructed for injection seeding of a high-power pulsed Ti:sapphire laser. The whole laser system operates as the transmitter of a scanning, ground-based, water-vapor differential absorption lidar (DIAL). The output of two seed lasers can be tuned in the wavelength range of 815–840 nm up to the power of 20 mW and switched between the online and offline wavelengths of the DIAL at frequencies of 0–1 kHz. The frequency stability of online and offline seed lasers is better than ±20 MHz rms and the mode-hop-free tuning range is greater than 40 GHz with external cavity diode lasers. The advantage of this system for efficient injection seeding of the Ti:sapphire cavity is that it is modular, robust, fully fiber-coupled, and polarization maintaining.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers
72.30.+q High-frequency effects; plasma effects
back to top
RSS Feeds

The ion-driven permeation experiment PERMEX

A. V. Golubeva, M. Mayer, Yu. M. Gasparyan, J. Roth, and V. A. Kurnaev

Rev. Sci. Instrum. 80, 073501 (2009); http://dx.doi.org/10.1063/1.3154385 (7 pages) | Cited 3 times

Online Publication Date: 7 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new installation PERMEX for the investigation of ion-driven permeation through metals was designed and built. A metal membrane under investigation separates two high-vacuum chambers. In the implantation chamber, the membrane surface is irradiated with a monoenergetic deuterium ion beam with an incident energy in the interval of 100–3000 eV/D. The ion flux at the surface is in a range of 1013–2×1014 D/cm2 s, the membrane temperature can be varied in the interval of 290–1050 K. The permeating deuterium flux from the outlet membrane surface to the volume of the second chamber (registration chamber) is measured by a quadrupole mass-analyzer. The outlet surface of the membrane can be cleaned by an argon ion beam. To approve the correct work of the setup a number of experiments were performed with Ni membranes. First results of experiments with tungsten membranes are presented.
Show PACS
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
82.45.Mp Thin layers, films, monolayers, membranes
66.30.J- Diffusion of impurities
28.41.Qb Structural and shielding materials

Doppler reflectometer system in the stellarator TJ-II

T. Happel, T. Estrada, E. Blanco, V. Tribaldos, A. Cappa, and A. Bustos

Rev. Sci. Instrum. 80, 073502 (2009); http://dx.doi.org/10.1063/1.3160106 (8 pages) | Cited 14 times

Online Publication Date: 10 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A Doppler reflectometer system has recently been installed in the stellarator TJ-II. The system is optimized for the Q-band (33–50 GHz) and the high-curvature plasmas produced in TJ-II. The launch angle of the microwave beam can be controlled by a steerable mirror to obtain angles between ±20° enabling the measurement of perpendicular wave numbers in the range of 3–15 cm−1. The available angular range allows for comparisons between positive and negative values and additionally for calibration of the system. Localization and k⊥-estimation is done via the three-dimensional ray/beam-tracing code TRUBA. First measured spectra and radial profiles of the perpendicular velocity of plasma density fluctuations are presented.
Show PACS
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Jd Magnetic mirrors, gas dynamic traps
52.25.-b Plasma properties

Beam emission spectroscopy for density turbulence measurements on the MAST spherical tokamak

A. R. Field, D. Dunai, N. J. Conway, S. Zoletnik, and J. Sárközi

Rev. Sci. Instrum. 80, 073503 (2009); http://dx.doi.org/10.1063/1.3170034 (12 pages) | Cited 7 times

Online Publication Date: 14 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Beam emission spectroscopy (BES) of the energetic deuterium (D0) heating beams can provide a means of characterizing the density turbulence in tokamak plasmas. First such measurements have been performed on the MAST spherical tokamak using a trial BES system, which shares the collection optics of the charge-exchange recombination spectroscopy system. This system, with eight spatial channels covering the outer part of the plasma cross section, uses avalanche photodiode detectors with custom preamplifiers to provide measurements at 1 MHz bandwidth with a spatial resolution of 4 cm. Simulations of the measurement, including the beam absorption and excitation, line-of-sight integration of the emission spectrum, and the characteristics of the detection system have been benchmarked against the measured absolute intensity of the Doppler shifted Dα fluorescence from the 50 keV beam. This gives confidence in predictions of the performance of a two-dimensional imaging BES system planned for MAST. Correlation techniques have also provided information on the characteristics of the density turbulence at the periphery of L-mode plasmas as well as density perturbations due to coherent magnetohydrodynamic activity at the edge of H-mode plasmas. Precursor oscillations of the density in the pedestal region to edge-localized modes occurring during H-mode plasmas with a single-null diverted magnetic configuration are also observable in the raw signals from the trial BES system.
Show PACS
52.35.Ra Plasma turbulence
52.55.Fa Tokamaks, spherical tokamaks
52.50.Gj Plasma heating by particle beams
52.30.Cv Magnetohydrodynamics (including electron magnetohydrodynamics)
52.35.Py Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.)
52.70.Nc Particle measurements
back to top
RSS Feeds

Multimodal optical workstation for simultaneous linear, nonlinear microscopy and nanomanipulation: Upgrading a commercial confocal inverted microscope

Manoj Mathew, Susana I. C. O. Santos, Dobryna Zalvidea, and Pablo Loza-Alvarez

Rev. Sci. Instrum. 80, 073701 (2009); http://dx.doi.org/10.1063/1.3142225 (11 pages) | Cited 7 times

Online Publication Date: 1 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this work we propose and build a multimodal optical workstation that extends a commercially available confocal microscope (Nikon Confocal C1-Si) to include nonlinear/multiphoton microscopy and optical manipulation/stimulation tools such as nanosurgery. The setup allows both subsystems (confocal and nonlinear) to work independently and simultaneously. The workstation enables, for instance, nanosurgery along with simultaneous confocal and brightfield imaging. The nonlinear microscopy capabilities are added around the commercial confocal microscope by exploiting all the flexibility offered by this microscope and without need for any mechanical or electronic modification of the confocal microscope systems. As an example, the standard differential interference contrast condenser and diascopic detector in the confocal microscope are readily used as a forward detection mount for second harmonic generation imaging. The various capabilities of this workstation, as applied directly to biology, are demonstrated using the model organism Caenorhabditis elegans.
Show PACS
07.60.Pb Conventional optical microscopes

Photothermal cantilever actuation for fast single-molecule force spectroscopy

Stefan W. Stahl, Elias M. Puchner, and Hermann E. Gaub

Rev. Sci. Instrum. 80, 073702 (2009); http://dx.doi.org/10.1063/1.3157466 (6 pages) | Cited 13 times

Online Publication Date: 1 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photothermal cantilever excitation provides a fast and easy to implement means to control the deflection of standard atomic force microscopy cantilevers. Minute heat pulses yield deflections on the order of several tens of nanometers or when the deflection is kept constant, forces of several hundreds of piconewton can be applied. In our case these pulses resulted in less than 1 K temperature changes at the sample position. Here we present and characterize the implementation of photothermal actuation for single-molecule force-spectroscopy experiments. When molecules are stretched under force-clamp conditions, fast control cycles that re-establish the pulling force after the rupture of molecular domains are essential for detecting the complete unfolding pattern with high precision. By combining the fast response of photothermal cantilever excitation with a conventional piezoactuator, a fast force-clamp with high accuracy and large working distances is reached. Simple feedback mechanisms and standard cantilever geometries lead to step response times of less than 90 μs, which is more than one order of magnitude faster than those of conventional force-clamp systems that are based only on piezo feedback. We demonstrate the fast and accurate performance of the setup by unfolding a protein construct consisting of one green fluorescent protein and eight surrounding immunoglobulin domains at constant force.
Show PACS
07.79.Lh Atomic force microscopes
36.20.-r Macromolecules and polymer molecules

Magnetic imaging with femtosecond temporal resolution

Jie Li, Min-Sang Lee, Wei He, Björn Redeker, Arndt Remhof, Edward Amaladass, Christoph Hassel, and Thomas Eimüller

Rev. Sci. Instrum. 80, 073703 (2009); http://dx.doi.org/10.1063/1.3170448 (5 pages) | Cited 5 times

Online Publication Date: 14 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A scanning Kerr microscope with a temporal resolution of <230 fs and a spatial resolution of 210 nm is presented. Equipped with a large temporal and spatial scanning range of 8 ns and 320 μm, respectively, the microscope allows studying nonuniform magnetization dynamics on many different time scales over a large area. For demonstration, we study the magnetization dynamics in Fe/Gd multilayer dot arrays exhibiting a spin reorientation transition (SRT) on three different time scales, namely, femtosecond, picosecond, and nanosecond scales. The dynamics on all time scales varies from one dot to another. This is attributed to the high sensitivity of the SRT to the variations of the layer thicknesses and the Fe/Gd interface structure.
Show PACS
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
78.47.-p Spectroscopy of solid state dynamics
75.40.Gb Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)
68.35.Ct Interface structure and roughness
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)

Microelectrophoresis in a laser trap: A platform for measuring electrokinetic interactions and flow properties within microstructures

V. Kahl, A. Gansen, R. Galneder, and J. O. Rädler

Rev. Sci. Instrum. 80, 073704 (2009); http://dx.doi.org/10.1063/1.3169511 (9 pages) | Cited 2 times

Online Publication Date: 17 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe a combination of microelectrophoresis and laser-trap methodology to accurately measure the electric force acting on a charged microsphere which is trapped in an optical tweezer. This field/trap apparatus allows measuring of the zeta potential with submillivolt accuracy and high temporal resolution. The combination with stop-flow techniques in principle provides a mean to observe adsorption or enzyme kinetics with single molecule sensitivity. We show that it is possible to accurately profile the position and frequency dependent hydrodynamic and electro-osmotic flow inside a microchannel structure of dimensions typically used in microfluidic applications without the need of fluorescent markers. We found good agreement to the theory of electrophoretic flow when retardation effects for rapidly alternating electric fields are included.
Show PACS
87.50.ch Electrophoresis/dielectrophoresis and other mechanical effects
87.80.Cc Optical trapping
87.80.Ek Mechanical and micromechanical techniques
87.15.Tt Electrophoresis
82.39.Wj Ion exchange, dialysis, osmosis, electro-osmosis, membrane processes
87.14.ej Enzymes

Automatic approaching method for atomic force microscope using a Gaussian laser beam

Cheolsu Han, Haiwon Lee, and Chung Choo Chung

Rev. Sci. Instrum. 80, 073705 (2009); http://dx.doi.org/10.1063/1.3181787 (7 pages) | Cited 2 times

Online Publication Date: 24 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this paper, a criterion for a fast automatic approach method in conventional atomic force microscope is introduced. There are currently two approach methods: automatic and semiautomatic methods. However, neither of them provides a high approach speed to enable the avoidance of possible damage to tips or samples. Industrial atomic force microscope requires a high approach speed and good repeatability for inspecting a large volume. Recently, a rapid automatic engagement method was reported to improve the approach speed. However, there was no information on how to determine the safe distance. This lack of information increases the chance for damage to occur in calibrating optimal approach speed. In this paper, we show that the proposed criterion can be used for decision making in determining mode transitions from fast motion to slow motion. The criterion is calculated based on the average intensity of a Gaussian laser beam. The tip-sample distance where the average intensity becomes the maximum value is used for the criterion. We explain the effects of the beam spot size and the window size on the average intensity. From experimental results with an optical head used in a commercial atomic force microscope, we observed that the mean and standard deviation (of the distance at which intensity is the maximum for the 25 experiments) are 194.0 and 15.0 μm, respectively, for a rectangular cantilever (or 224.8 and 12.6 μm for a triangular cantilever). Numerical simulation and experimental results are in good agreement.
Show PACS
07.79.Lh Atomic force microscopes

Three-dimensional surface profile measurement using a beam scanning chromatic confocal microscope

Byung Seon Chun, Kwangsoo Kim, and Daegab Gweon

Rev. Sci. Instrum. 80, 073706 (2009); http://dx.doi.org/10.1063/1.3184023 (7 pages) | Cited 2 times

Online Publication Date: 27 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this research, chromatic confocal microscopy with transverse point beam scanning is constructed for three-dimensional surface measurement without longitudinal mechanical translation. In beam scanning chromatic confocal microscopy, the wavelength-to-depth relation and the lateral field of view should be determined considering the beam scanning angle. With the experimental results from a sample structure, the three-dimensional profile is reconstructed by relating the wavelength and scanning angle to the axial and the lateral coordinates.
Show PACS
07.60.Pb Conventional optical microscopes
42.79.Ls Scanners, image intensifiers, and image converters

An infrared imaging method for high-throughput combinatorial investigation of hydrogenation-dehydrogenation and new phase formation of thin films

H. Oguchi, J. Hattrick-Simpers, I. Takeuchi, E. J. Heilweil, and L. A. Bendersky

Rev. Sci. Instrum. 80, 073707 (2009); http://dx.doi.org/10.1063/1.3184024 (7 pages) | Cited 7 times

Online Publication Date: 30 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg2Si phase in a Mg thin film on a thermally oxidized Si substrate during annealing.
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
61.72.Cc Kinetics of defect formation and annealing
82.45.Mp Thin layers, films, monolayers, membranes
82.30.-b Specific chemical reactions; reaction mechanisms

Development of a local vacuum system for focused ion beam machining

Tsuneaki Masuzawa, Yoshikazu Yoshida, Hiromichi Ikeda, Keigo Oguchi, Hikaru Yamagishi, and Yuji Wakabayashi

Rev. Sci. Instrum. 80, 073708 (2009); http://dx.doi.org/10.1063/1.3186060 (5 pages) | Cited 2 times

Online Publication Date: 31 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A local vacuum system for focused ion beam (FIB) processing, with a workpiece set in the air, has been developed. The local vacuum apparatus had a double-wall cylinder structure, used a differential exhaust, and each cylinder was connected to a vacuum exhaust pump. When the gap between the workpiece and the apparatus was 10 μm, the pressure of beam line in the machining head achieved 2.1×10−3 Pa. In addition, a visualization system was developed by visualizing the current flow out from a sample by FIB irradiation. With this system, it is possible to conduct focus adjustments of the FIB and shape recognition on a workpiece in the order of microns.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
07.30.Cy Vacuum pumps
81.20.Wk Machining, milling

A moving window correlation method to reduce the distortion of scanning probe microscope images

Wei Chu, Joseph Fu, Ronald Dixson, George Orji, and Theodore Vorburger

Rev. Sci. Instrum. 80, 073709 (2009); http://dx.doi.org/10.1063/1.3189041 (4 pages)

Online Publication Date: 31 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Many scanning probe microscopes such as the scanning tunneling microscope and atomic force microscope use piezoelectric actuators operating in open loop for generating the scans of the surfaces. However, nonlinearities mainly caused by hysteresis and drift of piezoelectric actuators reduce the positioning accuracy and produce distorted images. A moving window correlation method is proposed in this paper to determine and quantify the hysteresis. This method requires both trace and retrace profiles to be recorded. With a window imposed on each of the profiles, correlations are implemented between the data inside two windows to find corresponding pixel pairs on two different profiles but the same physical positions along the fast scanning axis (x). The x-distances between pixel pairs are calculated and then a simple correction scheme is applied to reduce the distortion.
Show PACS
07.79.Lh Atomic force microscopes
07.79.Cz Scanning tunneling microscopes
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
back to top
RSS Feeds

Novel device for simultaneous volumetric and x-ray diffraction measurements on metal-hydrogen systems

B. A. Talagañis, F. J. Castro, A. Baruj, and G. Meyer

Rev. Sci. Instrum. 80, 073901 (2009); http://dx.doi.org/10.1063/1.3157086 (6 pages)

Online Publication Date: 1 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Hydrogen storage materials can form more than one hydride phase. These different phases, in turn, display different hydrogen absorption/desorption capacities, kinetics, and stabilities. Studies aimed at characterizing and improving these materials usually need to correlate hydrogen intake with the precise determination of the hydride phase involved in the process. Here, we present a device designed to perform measurements of well known volumetric techniques with simultaneous x-ray diffraction on the material under study. The compact design can stand up to 6000 kPa of internal pressure while the sample can be heated up to 450 °C. The design process was assisted by finite element modeling and by the use of mock-up prototypes in order to optimize the thermal and under load behaviors. We provide two examples of use for this new device: (1) hydride decomposition in LaNi5 at 115 °C and (2) formation of MgCo during the programmed thermal desorption of the Mg2CoH5 hydride.
Show PACS
68.43.Mn Adsorption kinetics
68.43.Nr Desorption kinetics
68.43.Vx Thermal desorption
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
02.70.Dh Finite-element and Galerkin methods
84.60.-h Direct energy conversion and storage

Liquid mercury sound velocity measurements under high pressure and high temperature by picosecond acoustics in a diamond anvils cell

F. Decremps, L. Belliard, B. Couzinet, S. Vincent, P. Munsch, G. Le Marchand, and B. Perrin

Rev. Sci. Instrum. 80, 073902 (2009); http://dx.doi.org/10.1063/1.3160104 (3 pages) | Cited 4 times

Online Publication Date: 8 July 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Recent improvements to measure ultrasonic sound velocities of liquids under extreme conditions are described. Principle and feasibility of picosecond acoustics in liquids embedded in a diamond anvils cell are given. To illustrate the capability of these advances in the sound velocity measurement technique, original high pressure and high temperature results on the sound velocity of liquid mercury up to 5 GPa and 575 K are given. This high pressure technique will certainly be useful in several fundamental and applied problems in physics and many other fields such as geophysics, nonlinear acoustics, underwater sound, petrology or physical acoustics.
Show PACS
43.58.Dj Sound velocity
07.20.Ka High-temperature instrumentation; pyrometers
07.35.+k High-pressure apparatus; shock tubes; diamond anvil cells
62.60.+v Acoustical properties of liquids
06.60.Jn High-speed techniques (microsecond to femtosecond)
07.64.+z Acoustic instruments and equipment
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Your Recent History Recent History Help

Recently Viewed

  1. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules
  2. Imaging photoelectron photoion coincidence spectroscopy with velocity focusing electron optics
  3. Microwave absorption measurements using a broad-band meanderline approach
  4. Automated spin-assisted layer-by-layer assembly of nanocomposites
Go to AIP Home
Copyright © American Institute of Physics
close