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

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

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

Apr 2001

Volume 72, Issue 4, pp. 1937-2225

Page 1 of 2 Pages Next Page | Jump to Page
back to top
RSS Feeds

Application of acoustic resonators in photoacoustic trace gas analysis and metrology

András Miklós, Peter Hess, and Zoltán Bozóki

Rev. Sci. Instrum. 72, 1937 (2001); http://dx.doi.org/10.1063/1.1353198 (19 pages) | Cited 127 times

Full Text: | Download PDF

Show Abstract
The application of different types of acoustic resonators such as pipes, cylinders, and spheres in photoacoustics is considered. This includes a discussion of the fundamental properties of these resonant cavities. Modulated and pulsed laser excitation of acoustic modes is discussed. The theoretical and practical aspects of high-Q and low-Q resonators and their integration into complete photoacoustic detection systems for trace gas monitoring and metrology are covered in detail. The characteristics of the available laser sources and the performance of the photoacoustic resonators, such as signal amplification, are discussed. Setup properties and noise features are considered in detail. This review is intended to give newcomers the information needed to design and construct state-of-the-art photoacoustic detectors for specific purposes such as trace gas analysis, spectroscopy, and metrology. © 2001 American Institute of Physics.
Show PACS
82.80.Kq Energy-conversion spectro-analytical methods (e.g., photoacoustic, photothermal, and optogalvanic spectroscopic methods)
01.30.Rr Surveys and tutorial papers; resource letters
43.35.Ud Thermoacoustics, high temperature acoustics, photoacoustic effect
43.58.Kr Spectrum and frequency analyzers and filters; acoustical and electrical oscillographs; photoacoustic spectrometers; acoustical delay lines and resonators
07.88.+y Instruments for environmental pollution measurements
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
back to top
RSS Feeds
back to top OPTICS; ATOMS and MOLECULES; SPECTROSCOPY

Portable, tunable, high-luminosity spherical crystal spectrometer with an x-ray charge coupled device, for high-resolution x-ray spectromicroscopy of clusters heated by femtosecond laser pulses

F. Blasco, C. Stenz, F. Salin, A. Ya. Faenov, A. I. Magunov, T. A. Pikuz, and I. Yu. Skobelev

Rev. Sci. Instrum. 72, 1956 (2001); http://dx.doi.org/10.1063/1.1355273 (7 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
A portable (200×100×100 mm3), high-luminosity, spherically bent crystal spectrometer was designed for measuring in a wide spectral range of 1.2–19.6 Å very low emissivity x-ray spectra of different clusters heated by 35 fs laser radiation. This spectrometer is associated with a custom design x-ray charge coupled device that features a large sensitive area (24.6×24.6 mm2) and a small pixel size (24×24 μm2). This apparatus provides simultaneous high spectral (λ/δλ ∼ 1000–5000) and spatial (40–80 μm) resolution. A large (30×10 mm2) open aperture mica crystal with R = 100 mm is used as the dispersive and focusing element. The large tuneability of the spectrometer makes it possible to record high-resolution spectra of H-like ions of oxygen (CO2 clusters) in a spectral range of 15–17 Å, Ne-like like ions of Kr in a spectral range of 5–5.7 Å, and He-like spectra of Ar in a spectral range of 3.0–3.4 and 3.7–4.4 Å without any adjustment of the spectrometer setup. Thanks to the high luminosity (high collection efficiency) of the spectrometer, high quality spectra were obtained using only 15 mJ 2000 laser shots. © 2001 American Institute of Physics.
Show PACS
07.85.Nc X-ray and γ-ray spectrometers
85.60.Gz Photodetectors (including infrared and CCD detectors)
36.40.Mr Spectroscopy and geometrical structure of clusters
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment
07.60.-j Optical instruments and equipment

Multimass ion imaging detection: Application to photodissociation

Shang-Ting Tsai, Chih-Kai Lin, Yuan T. Lee, and Chi-Kung Ni

Rev. Sci. Instrum. 72, 1963 (2001); http://dx.doi.org/10.1063/1.1359188 (7 pages) | Cited 38 times

Full Text: | Download PDF

Show Abstract
A constant momentum mass spectrometer with a two-dimensional ion detector in conjunction with a pulsed vacuum ultraviolet laser is used for the simultaneous measurement of the translational energy distributions of many different fragments. A description of the apparatus and its performance are presented. Preliminary experimental results on the photodissociation of toluene and benzene are given. © 2001 American Institute of Physics.
Show PACS
07.75.+h Mass spectrometers
37.20.+j Atomic and molecular beam sources and techniques
33.80.Gj Diffuse spectra; predissociation, photodissociation

Enhanced Raman sensitivity using an actively stabilized external resonator

David J. Taylor, Manfred Glugla, and Ralf-Dieter Penzhorn

Rev. Sci. Instrum. 72, 1970 (2001); http://dx.doi.org/10.1063/1.1353190 (7 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
An enhancement up to 250-fold in laser Raman signals for real-time gas analysis has been achieved within an actively stabilized external resonator (ASER), whose length is actively matched to the single-frequency excitation laser using the Pound–Drever technique. With the Raman cell present, enhancements up to 50-fold are achieved, and the resulting detection limit for hydrogen in ambient-pressure gas mixtures is about ten parts-per-million in a 1 min analysis period at unity signal-to-noise ratio. Based upon the recent development of a fiber-pumped Nd:YVO4 laser with single-frequency output exceeding 5 W at 532 nm, this highly sensitive instrument is applied to detection of tritiated gases, wherein the compactness and low heat of this laser head permit placing the entire optical system, including laser head, charge coupled Raman detector, and ASER, within the glove box necessary for secondary containment of tritium, thereby accomplishing a robust, highly sensitive Raman analytical system for hazardous substances. © 2001 American Institute of Physics.
Show PACS
82.80.Gk Analytical methods involving vibrational spectroscopy
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Tunable pulsed vacuum ultraviolet light source for surface science and materials spectroscopy based on high order harmonic generation

D. Riedel, J. L. Hernandez-Pozos, R. E. Palmer, S. Baggott, K. W. Kolasinski, and J. S. Foord

Rev. Sci. Instrum. 72, 1977 (2001); http://dx.doi.org/10.1063/1.1351835 (7 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
We report here the development of a tunable vacuum ultraviolet light source, providing subpicosecond pulses over the wavelength range from 114 (∼11 eV) to 32 nm (∼39 eV), designed for surface science experiments. The source is based on high order harmonic generation. The experimental setup is described in detail and the harmonic yield as a function of the gas type (xenon or argon) is compared with theoretical descriptions. We address in particular the tunability of the source, desirable for surface science applications. Absolute characterization of the harmonic yield has also been performed and validated with time-resolved fluorescence measurements. The results are extremely promising, with intensities of ∼ 1010 photons/s, with regard to the use of this coherent source for surface science and spectroscopy. © 2001 American Institute of Physics.
Show PACS
42.72.Bj Visible and ultraviolet sources
07.60.Rd Visible and ultraviolet spectrometers
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Elimination of amplitude-phase crosstalk in frequency domain near-infrared spectroscopy

S. P. Morgan and K. Y. Yong

Rev. Sci. Instrum. 72, 1984 (2001); http://dx.doi.org/10.1063/1.1357233 (4 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Changes in phase that occur with changes in amplitude impose severe limitations on the accuracy of frequency domain near-infrared spectrometers. Phase is related to the photon pathlength in tissue and phase errors introduced by the instrument can be interpreted as changes in tissue oxygenation. The instrument described in this article employs a reference radio frequency modulated laser diode to eliminate the effects of amplitude-phase crosstalk and requires no feedback. Light from the reference laser diode does not pass through the medium under investigation but passes directly onto the detector. The reference and medium signals follow a common path through the detector and so the same phase error is imposed on both. Summing the reference and medium phase eliminates the crosstalk and enables the resultant to be attributed only to the photon pathlength within the medium. It is also demonstrated that elimination of amplitude-phase crosstalk is a natural consequence of a phased array configuration. © 2001 American Institute of Physics.
Show PACS
87.64.K- Spectroscopy
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques

The spectral linewidth of tunable semiconductor InAsSb/InAsSbP lasers emitting at 3.2–3.6 μm (2800–3100 cm−1)

A. N. Imenkov, N. M. Kolchanova, Yu. P. Yakovlev, P. Kubát, and S. Civiš

Rev. Sci. Instrum. 72, 1988 (2001); http://dx.doi.org/10.1063/1.1353194 (5 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
A method was used to measure the width of emission lines of a type of semiconductor laser with composition InAsSb/InAsSbP. This type of laser was manufactured specially for absorption high-resolution spectroscopy of gases absorbing in the 2800–3100 cm−1 region. Parameters used for calculation of spectral emission linewidths were obtained using selected rotation-vibration lines of the gaseous molecules N2O, CH3Cl, and OCS. The estimated spectral emission linewidths varied in the range 10–30 MHz in dependence of the current passing and the type of laser. © 2001 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment
07.60.-j Optical instruments and equipment
42.60.Fc Modulation, tuning, and mode locking

A comparison of glass fluorescers used to measure a pulsed ultraviolet image at F/2

A. V. Deniz and J. A. Stamper

Rev. Sci. Instrum. 72, 1993 (2001); http://dx.doi.org/10.1063/1.1353195 (6 pages)

Full Text: | Download PDF

Show Abstract
We built and characterized an instrument to measure the output profile of a pulsed KrF laser. The laser beam is focused onto a ∼1-mm-thick fluorescer, and the resulting fluorescence is imaged by a charge coupled device (CCD) camera. We tested 21 materials for efficiency, linearity, and fidelity. The best material is Schott BG-26 color filter glass. It has acceptable linearity for a fluence of 50 mJ/cm2, and a spatial resolution of ∼50 μm with a laser convergence angle of 30° (F/2), when the fluorescence is imaged with F/3 optics. We present a list of the materials tested and comparisons of profiles measured by using the fluorescer and by direct recording with a CCD camera. © 2001 American Institute of Physics.
Show PACS
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.70.Ce Glasses, quartz
42.79.Ls Scanners, image intensifiers, and image converters
42.55.Lt Gas lasers including excimer and metal-vapor lasers

Quantitative measurement system of molecular orientation by coaxial optical Kerr effect spectroscopy

Keiji Sakai, Yasuhiro Ikeda, and Kenshiro Takagi

Rev. Sci. Instrum. 72, 1999 (2001); http://dx.doi.org/10.1063/1.1355271 (4 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We have developed a new system for quantitative measurement of laser induced molecular orientation spectroscopy with continuous wave lasers operating in a coaxial configuration. An exciting Ar+ laser and a probing He–Ne laser are superimposed coaxially and incident to the liquid sample of anisotropic molecules, in which the former drives the molecules into the direction of light polarization, while the latter picks up the induced molecular orientation as the Kerr effect. The new system realizes long interaction lengths of the exciting and probing beams, which enables us to measure the molecular orientation with high sensitivity even for materials with small Kerr constant. Quantitative estimation of the Kerr constant also becomes possible by measuring accurate profiles of the laser beams. The strength of the Kerr effect was theoretically calculated on the basis of the optics of the Gaussian beam propagation and the relation between the expected signal intensity and the optical configuration was derived. The experimental result obtained for liquid carbon disulfide shows good agreement with theory. © 2001 American Institute of Physics.
Show PACS
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
07.60.Rd Visible and ultraviolet spectrometers
61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
61.20.Lc Time-dependent properties; relaxation
back to top PARTICLE SOURCES, OPTICS and ACCELERATION

Application and methodological improvements to the floating-wire technique to characterize the magnetic properties of a spectrometer dipole

H. J. Stein, G. Krol, S. Barsov, and V. Koptev

Rev. Sci. Instrum. 72, 2003 (2001); http://dx.doi.org/10.1063/1.1357232 (8 pages)

Full Text: | Download PDF

Show Abstract
The floating wire technique was applied to characterize the focusing properties of the D2 spectrometer magnet to be used in the ANKE installation of the COSY Jülich accelerator facility. Trajectories corresponding to 140–600 MeV/c ejectiles emerging from a target in front of the rectangular-type D2 magnet were measured in order to determine the location of foci where detectors for the physics experiments were to be placed. The focus for trajectories of the same momentum was localized by varying the trajectory start angle at the target. To overcome the problem of instability, which arises when the pulley has to be located behind the focus, an unbalanced pulley was used. Other improvements include methodological features such as the particular design of our air-bearing pulley enabling a “freezing-in” of the wire movement and therefore yielding a very high accuracy of the wire position measurement, the use of a 40 μm gold-plated tungsten wire best fulfilling the mechanical and electrical requirements, a fast-regulating power supply in combination with an absolutely calibrated current meter, and the excellent accuracy of modern surveying instrumentation. An overall momentum accuracy of Δp/p ⩽ 10−3 and a position accuracy of the trajectories of ±1 mm in the vicinity of the foci have been demonstrated. The precision and accuracy of the floating-wire measurements are discussed and compared with ray-tracing calculations based on measured and calculated field maps. © 2001 American Institute of Physics.
Show PACS
29.30.-h Spectrometers and spectroscopic techniques
29.27.Fh Beam characteristics

Triple drift ion beam bunching systems for enhanced bunching efficiency

P. R. Sarma, V. S. Pandit, and R. K. Bhandari

Rev. Sci. Instrum. 72, 2011 (2001); http://dx.doi.org/10.1063/1.1355272 (4 pages)

Full Text: | Download PDF

Show Abstract
To obtain high efficiency in bunching ions one generally uses a multiharmonic buncher or a double drift buncher. Here we have explored the possiblity of using a triple drift bunching system to obtain still higher bunching efficiency. It consists of three bunchers separated in space. The first buncher is excited with the fundamental rf wave whereas the other two bunchers are driven by the second harmonic. We have optimized the parameters of such a system and have shown that by using only two rf frequencies one can obtain bunching efficiency higher than what can be obtained with a multiharmonic buncher consisting of nine harmonics. © 2001 American Institute of Physics.
Show PACS
29.27.Eg Beam handling; beam transport
02.60.Pn Numerical optimization
07.77.Ka Charged-particle beam sources and detectors
back to top NUCLEAR PHYSICS, FUSION and PLASMAS

Liquid impedance matching system for ion cyclotron heating

K. Saito, Y. Torii, R. Kumazawa, T. Mutoh, T. Seki, F. Shimpo, G. Nomura, M. Yokota, T. Watari, G. Cattanei, and Yangping Zhao

Rev. Sci. Instrum. 72, 2015 (2001); http://dx.doi.org/10.1063/1.1350636 (8 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
Ion cyclotron heating has been established as one of the heating schemes in nuclear fusion research and its use in steady state plasma heating in various devices is being considered. The optimal technology for steady state ion cyclotron range of frequency heating has not been firmly established. This article reports on the liquid stub tuner which was newly developed in research and development activities on the large helical device. It demonstrated high performance in real use in experiments. Two different impedance-matching systems based on the liquid stub tuner are studied: one is a triple liquid stub tuner system and the other is a single stub tuner system with a liquid phase shifter. The characteristics of the two systems are compared from the points of view of how wide a frequency range is covered, and how great the reduction of the voltage in the transmission line is. © 2001 American Institute of Physics.
Show PACS
52.50.Qt Plasma heating by radio-frequency fields; ICR, ICP, helicons
52.55.Jd Magnetic mirrors, gas dynamic traps

Charge-coupled device systems for recording two-dimensional multi-mega-ampere z-pinch data

B. H. Failor, P. L. Coleman, J. S. Levine, Y. Song, H. Sze, P. D. LePell, C. A. Coverdale, C. Deeney, L. Pressley, and R. Schneider

Rev. Sci. Instrum. 72, 2023 (2001); http://dx.doi.org/10.1063/1.1355264 (9 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
Hardware and software have been developed for recording and displaying accurate image and spectral data produced by z-pinch plasma radiation sources at the Double-EAGLE facility at Maxwell Physics International. Desktop computers are used to acquire the data, analyze it, and display and print the results. Of the four charge-coupled device (CCD) image recording systems implemented, two record x rays directly and two record optical light emission from electron–excited phosphors. The CCD systems required careful shielding to allow them to operate in the harsh radio frequency noise environment. During a series of shots at the SATURN facility at Sandia National Laboratories, the quality of a keV x-ray spectrum recorded directly with a CCD compared well with an equivalent spectrum recorded with 2497 film. © 2001 American Institute of Physics.
Show PACS
52.58.Lq Z-pinches, plasma focus, and other pinch devices
52.70.La X-ray and γ-ray measurements
52.59.Px Hard X-ray sources
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors

Time-resolved measurement on ablative acceleration of foil plates driven by pulsed laser beam

Hongliang He, T. Kobayashi, and T. Sekine

Rev. Sci. Instrum. 72, 2032 (2001); http://dx.doi.org/10.1063/1.1357227 (4 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
Coupled with the push-pull type velocity interferometer system for any reflector, an electronic streak camera recording system has been established, which provides subnanosecond time resolution in the detection of interferential fringes. Complete acceleration histories of Al, Au, and Pt foil plates, driven by pulsed laser beam at 30–400 GW/cm2, have been measured by using this system. For the 10-μm-thick Al foil irradiated at 280 GW/cm2, an ablative acceleration up to terminal velocity about 9 km/s within 25 ns has been determined with a velocity uncertainty of ∼1%. © 2001 American Institute of Physics.
Show PACS
52.38.Mf Laser ablation
06.30.Gv Velocity, acceleration, and rotation
52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
07.60.Ly Interferometers

On the theory of an Omegatron with asymmetric three-dimensional electric fields: Ion trajectories and resonance peak shapes

P. V. Amerl, H. R. Krouse, and H. Fichtner

Rev. Sci. Instrum. 72, 2036 (2001); http://dx.doi.org/10.1063/1.1357229 (7 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
The theory and modeling of an Omegatron, an instrument exploiting the cyclotron resonance principle for various laboratory measurements, is revisited. A general model for the ion motion in the instrument is developed to compute expected resonance peak shapes. In order to numerically integrate the equation of ion motion, the actual three-dimensional electric field in which the ions move is computed. With this model, the influence of various parameters on the shape of the resonance peaks is studied, and the theoretical findings are compared with experimental results. © 2001 American Institute of Physics.
Show PACS
07.75.+h Mass spectrometers
41.85.-p Beam optics
41.20.Cv Electrostatics; Poisson and Laplace equations, boundary-value problems

Unique broad-spectrum neutron sensing instrument

J. A. Weaver, M. J. Joyce, A. J. Peyton, J. Roskell, and M. J. Armishaw

Rev. Sci. Instrum. 72, 2043 (2001); http://dx.doi.org/10.1063/1.1353191 (5 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
This article reviews the design and operation of a transportable neutron spectrometer. Four of these instruments were produced and have been widely used for applications such as the assessment and classification of radiation hazards at field sites in the United Kingdom and Europe. An overview of the instrument hardware is presented, together with a description of the six sensor channels, their associated processing electronics and the host data logger computer. Spectral unfolding is also summarized and a sample spectra, which was measured from outside a fuel flask, is given. © 2001 American Institute of Physics.
Show PACS
29.30.Hs Neutron spectroscopy
29.50.+v Computer interfaces
07.05.Wr Computer interfaces

Absolute calibration of laser-induced fluorescence experiments by optical depth correction

St. Franke, A. Dinklage, and C. Wilke

Rev. Sci. Instrum. 72, 2048 (2001); http://dx.doi.org/10.1063/1.1355267 (4 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Laser-induced fluorescence measurements are absolutely calibrated by correction of relative spatial fluorescence profiles for optical depth. The method is applicable if optical depths of fluorescence transitions are sufficiently high (mean optical depth math≳0.3). For calibration two relative spatial density profiles are required. Measurements of absolute particle densities in a dc glow discharge are performed and compared to results of laser absorption spectroscopy. Absolute errors are found to be less than 20%. The calibration method is expected to be useful in experimental environments that are not accessible for other calibration methods, e.g., due to high optical depth. © 2001 American Institute of Physics.
Show PACS
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
07.60.Rd Visible and ultraviolet spectrometers
42.62.Fi Laser spectroscopy
06.20.F- Units and standards

Contamination-free sounding rocket Langmuir probe

W. E. Amatucci, P. W. Schuck, D. N. Walker, P. M. Kintner, S. Powell, B. Holback, and D. Leonhardt

Rev. Sci. Instrum. 72, 2052 (2001); http://dx.doi.org/10.1063/1.1357234 (6 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
A technique for removing surface contaminants from a sounding rocket spherical Langmuir probe is presented. Contamination layers present on probe surfaces can skew the collected data, resulting in the incorrect determination of plasma parameters. Despite following the usual probe cleaning techniques that are used prior to a launch, the probe surface can become coated with layers of adsorbed neutral gas in less than a second when exposed to atmosphere. The laboratory tests reported here show that by heating the probe from the interior using a small halogen lamp, adsorbed neutral particles can be removed from the probe surface, allowing accurate plasma parameter measurements to be made. © 2001 American Institute of Physics.
Show PACS
07.87.+v Spaceborne and space research instruments, apparatus, and components (satellites, space vehicles, etc.)
95.55.Pe Lunar, planetary, and deep-space probes
52.70.Ds Electric and magnetic measurements
back to top BASIC PHENOMENA

A double coil apparatus for Barkhausen noise measurements

E. Puppin, M. Zani, D. Vallaro, and A. Venturi

Rev. Sci. Instrum. 72, 2058 (2001); http://dx.doi.org/10.1063/1.1353193 (4 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
A pickup coil wound around the sample is the standard method for Barkhausen noise (BN) measurements. Here we describe an apparatus where two coils are used instead of one. The relative position of the coils can be changed and this allows the experimental investigation of spatial correlation effects in BN. The signals induced in the coils are very similar when the coils are placed nearby whereas a progressive decrease of their correlation is observed by moving the coils apart. We tested our system on a ribbon of amorphous Fe63B14Si8Ni15 100 mm long. For a distance between the coils of 40 mm the signal correlation is nearly vanished. © 2001 American Institute of Physics.
Show PACS
07.55.-w Magnetic instruments and components
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
84.32.Hh Inductors and coils; wiring
75.50.Kj Amorphous and quasicrystalline magnetic materials
75.50.Bb Fe and its alloys
back to top MICROSCOPY and IMAGING

A high-throughput x-ray microtomography system at the Advanced Photon Source

Yuxin Wang, Francesco De Carlo, Derrick C. Mancini, Ian McNulty, Brian Tieman, John Bresnahan, Ian Foster, Joseph Insley, Peter Lane, Gregor von Laszewski, Carl Kesselman, Mei-Hui Su, and Marcus Thiebaux

Rev. Sci. Instrum. 72, 2062 (2001); http://dx.doi.org/10.1063/1.1355270 (7 pages) | Cited 51 times

Full Text: | Download PDF

Show Abstract
A third-generation synchrotron radiation source provides enough brilliance to acquire complete tomographic data sets at 100 nm or better resolution in a few minutes. To take advantage of such high-brilliance sources at the Advanced Photon Source, we have constructed a pipelined data acquisition and reconstruction system that combines a fast detector system, high-speed data networks, and massively parallel computers to rapidly acquire the projection data and perform the reconstruction and rendering calculations. With the current setup, a data set can be obtained and reconstructed in tens of minutes. A specialized visualization computer makes rendered three-dimensional (3D) images available to the beamline users minutes after the data acquisition is completed. This system is capable of examining a large number of samples at sub-μm 3D resolution or studying the full 3D structure of a dynamically evolving sample on a 10 min temporal scale. In the near future, we expect to increase the spatial resolution to below 100 nm by using zone-plate x-ray focusing optics and to improve the time resolution by the use of a broadband x-ray monochromator and a faster detector system. © 2001 American Institute of Physics.
Show PACS
07.85.Qe Synchrotron radiation instrumentation
07.85.Tt X-ray microscopes
07.05.Hd Data acquisition: hardware and software
07.05.Pj Image processing

Adaptation to low temperatures of a differential interference contrast microscope with subnanometer sensitivity

X. Müller, T. Kinoshita, and J. Dupont-Roc

Rev. Sci. Instrum. 72, 2069 (2001); http://dx.doi.org/10.1063/1.1351834 (4 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
We show how a differential interference contrast microscope can be adapted for low temperature operation by having only the microscope objective at low temperatures. The microscope’s body, with delicate birefringent optics, is kept at room temperature. A key part is the use of two Wollaston prisms with opposite anisotropic media to ensure a flat field. The device can detect optical path differences of the order of 10 pm/μm with a few seconds of integration time. Images taken at several hour intervals can be subtracted, indicating good mechanical stability. © 2001 American Institute of Physics.
Show PACS
07.60.Pb Conventional optical microscopes
07.20.Mc Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment
42.79.Bh Lenses, prisms and mirrors

Near-field scanning microwave probe based on a dielectric resonator

M. Abu-Teir, M. Golosovsky, D. Davidov, A. Frenkel, and H. Goldberger

Rev. Sci. Instrum. 72, 2073 (2001); http://dx.doi.org/10.1063/1.1351837 (7 pages) | Cited 36 times

Full Text: | Download PDF

Show Abstract
We report a near-field microwave microscopy based on a novel scanning probe—a long and narrow slot microfabricated on the convex surface of the dielectric resonator. The probe is mounted in the cylindrical waveguide. Tunable coupling to the probe is effectuated through the variable air gap. The whole probe is very compact, has a coaxial input, operates at 25–30 GHz, has a spatial resolution of 1–10 μm and, most important, has a low impedance of ∼20 Ω. This allows us to use it for characterization of metallic layers with high conductivity, in particular, thickness mapping. © 2001 American Institute of Physics.
Show PACS
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment
84.40.Az Waveguides, transmission lines, striplines
07.79.-v Scanning probe microscopes and components
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Detailed description of a compact cryogenic magnetic resonance force microscope

Doran D. Smith, John A. Marohn, and Lee E. Harrell

Rev. Sci. Instrum. 72, 2080 (2001); http://dx.doi.org/10.1063/1.1357230 (10 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We describe the design and operation of a cryogenic magnetic resonance force microscope for detecting nuclear magnetic resonance. Instrument-critical details are enumerated, including fabrication of a positionable radio-frequency coil, detection of angstrom-level microcantilever oscillations using an optical fiber interferometer, design of a compact fiber/cantilever alignment system, temperature compensation of the fiber/cantilever gap, control of sample temperature, and vibration isolation. Additionally, experimental protocols and sample specific considerations such as spin relaxation times are addressed. 19F nuclear magnetic resonance data obtained from a Nd-doped CaF2 sample are presented.
Show PACS
07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques
07.79.Pk Magnetic force microscopes
07.20.Mc Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment
07.60.Ly Interferometers
07.60.Vg Fiber-optic instruments

A scanning superconducting quantum interference device microscope with high spatial resolution for room temperature samples

Friederike Gruhl, Michael Mück, Marc von Kreutzbruck, and Jörg Dechert

Rev. Sci. Instrum. 72, 2090 (2001); http://dx.doi.org/10.1063/1.1359189 (7 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
We have developed a scanning superconducting quantum interference device (SQUID) microscope based on niobium tunnel junction direct current (dc) SQUIDs. It employs either a SQUID magnetometer or a planar first order gradiometer with an effective area of 40×40 μm2 and a magnetic field resolution on the order of 1 pT/√Hz at frequencies above a few hertz. The gradiometer has a base line of 1 mm. The SQUIDs are mounted inside the insulation vacuum of a fiberglass helium Dewar, and are thermally coupled to the helium bath via a brass block. A sapphire window with a thickness of about 50 μm separates the SQUIDs from the room temperature sample. We have also investigated different window materials, such as tungsten or iridium, and found them equally useful. The stand-off distance between SQUID and room temperature sample can be as low as 75 μm, and the spatial resolution of the microscope is about 50–100 μm. The SQUID sensor is read out using conventional dc SQUID electronics with a bandwidth of 1 kHz and a slew rate of 200 mT/s. A computer controlled x–y stage scans the sample below the microscope. With this microscope, we have investigated magnetic signatures of magnetic storage media, ferromagnetic and paramagnetic inclusions in geological and biological samples as well as platinum coins, and have also performed nondestructive testing of stainless steel plates and aircraft parts with high spatial resolution. © 2001 American Institute of Physics.
Show PACS
07.55.Ge Magnetometers for magnetic field measurements
85.25.Dq Superconducting quantum interference devices (SQUIDs)

Superconducting niobium tip for scanning tunneling microscope light emission spectroscopy

Y. Uehara, T. Fujita, M. Iwami, and S. Ushioda

Rev. Sci. Instrum. 72, 2097 (2001); http://dx.doi.org/10.1063/1.1350644 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Niobium tips for use in scanning tunneling microscope (STM) light emission measurements have been fabricated by an electrochemical etching method. The typical radius of curvature of the tip is less than 100 nm. The Nb tip has been demonstrated to be capable of producing STM images of highly oriented pyrolytic graphite and Au(110)-(2×1) surfaces with atomic spatial resolution. It has been confirmed by STM light emission spectroscopy that the front of the Nb tip becomes superconducting for temperatures below the superconducting transition temperature of Nb. © 2001 American Institute of Physics.
Show PACS
07.79.Cz Scanning tunneling microscopes
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
74.50.+r Tunneling phenomena; Josephson effects
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)
81.65.Cf Surface cleaning, etching, patterning
68.35.B- Structure of clean surfaces (and surface reconstruction)
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close