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

Sep 2009

Volume 80, Issue 9, Articles (09xxxx)

Return to All Sections
back to top
RSS Feeds

Precise determination of the pressure distortion coefficient of new controlled-clearance piston-cylinders based on the Heydemann–Welch model

Hiroaki Kajikawa, Kazunori Ide, and Tokihiko Kobata

Rev. Sci. Instrum. 80, 095101 (2009); http://dx.doi.org/10.1063/1.3203150 (10 pages) | Cited 2 times

Online Publication Date: 2 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new controlled-clearance (CC) pressure balance has been developed with the aim of improving hydraulic pressure standards up to pressures of 1 GPa. The pressure balance is equipped with a weight-loading unit that can load/unload selected weights automatically and a CC piston-cylinder that is designed for the jacket pressure to be applied independently. In this paper, the effective area Ae of two kinds of the CC piston-cylinders for pressures of 200 and 500 MPa was examined based on the Heydemann–Welch model. The two parameters in the model, the jacket pressure coefficient and the zero clearance jacket pressure, were precisely determined by the characterization experiments, after which the pressure dependence of Ae and its uncertainty were estimated. The uncertainty due to the pressure dependence of Ae for the 500 MPa CC piston-cylinder was less than 7.5×10−8 MPa−1. To confirm the consistency of the estimations, the results of the two CC piston-cylinders were compared through a free-deformation (FD) piston-cylinder; the two estimations were in agreement with each other. Moreover, it was shown that the extent of nonlinearity in the pressure dependence of Ae of the FD piston-cylinder can be evaluated by calibration against the CC piston-cylinder.
Show PACS
89.20.Kk Engineering

Transient measurement of light-emitting diode characteristic parameters for production lines

Shengjun Zhou and Sheng Liu

Rev. Sci. Instrum. 80, 095102 (2009); http://dx.doi.org/10.1063/1.3212573 (7 pages) | Cited 2 times

Online Publication Date: 4 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new instrument has been developed for transient measurement of light-emitting diodes (LEDs), including photometric parameters, colorimetric parameters, and electrical parameters in a matter of milliseconds, by combining spectrometer with a human photopic vision detector and data acquisition card (DAQ). The instrument can provide communication interface for sorter to realize automatic sorting of measured LEDs samples. The light emitted from the measured LEDs, which are illuminated under pulse current operation condition, is captured by the spectrometer and the human photopic vision detector. The spectral power distributions of LEDs are recorded by spectrometer, and processed to provide colorimetric parameters. We employ two novel algorithms including look-up table method and curve fitting method to determine the dominant wavelength of LED. In combination with linear interpolation, the look-up table method can locate dominant wavelength with a resolution of 0.1 nm. A programmable constant current source/voltage source is designed for power supply to drive LED. The luminous intensity of LED can be derived by detecting the photocurrent of human photopic vision detector. We also describe the calibration of the human photopic vision detector. This calibration provides detector-specific correction factor that enables accurate extraction of luminous intensity of LED. The instrument has been used to measure and inspect the quality of packaging LED.
Show PACS
85.60.Jb Light-emitting devices
07.60.Dq Photometers, radiometers, and colorimeters
06.60.Mr Testing and inspecting procedures

Development of metal nanocluster ion source based on dc magnetron plasma sputtering at room temperature

Abhijit Majumdar, Daniel Köpp, Marina Ganeva, Debasish Datta, Satyaranjan Bhattacharyya, and Rainer Hippler

Rev. Sci. Instrum. 80, 095103 (2009); http://dx.doi.org/10.1063/1.3213612 (6 pages) | Cited 2 times

Online Publication Date: 4 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple and cost effective nanocluster ion source for the deposition of size selected metal nanocluster has been developed based on the dc magnetron discharge (including pulsed dc discharge). The most important and interesting feature of this cluster source is that it is working at room temperature, cooled by chilled water during the experiment. There is no extraction unit in this device and the cluster streams flow only due to the pressure gradient from source chamber to substrate via quadrupole mass filter. It has provision of multiple substrate holders in the deposition chamber, which can be controlled manually. The facility consists of quadrupole mass filter (QMF 200), which can select masses in the range of 2–125 000 atoms depending on the target materials, with a constant mass resolution (M/ΔM ∼ 25). The dc magnetron discharge at a power of about 130 W with Ar as feed/buffer gas was used to produce the Cu nanocluster in an aggregation tube and deposited on Si (100) wafer temperature.
Show PACS
81.07.Bc Nanocrystalline materials
52.80.-s Electric discharges
61.46.Bc Structure of clusters (e.g., metcars; not fragments of crystals; free or loosely aggregated or loosely attached to a substrate)
81.16.-c Methods of micro- and nanofabrication and processing
81.15.Cd Deposition by sputtering
52.77.Dq Plasma-based ion implantation and deposition

Small single-crystal silicon cantilevers formed by crystal facets for atomic force microscopy

Kazuhisa Nakagawa, Gen Hashiguchi, and Hideki Kawakatsu

Rev. Sci. Instrum. 80, 095104 (2009); http://dx.doi.org/10.1063/1.3202322 (5 pages) | Cited 4 times

Online Publication Date: 8 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed a batch fabrication method of small cantilevers formed by crystal facets of single-crystal silicon for improving the sensitivity of atomic force microscopy. In order to realize a small cantilever with a very sharp tip, we have employed KOH anisotropic etching and local oxidation of silicon. We have made two types of small cantilevers, the V-shaped triangular type and the bulk triangular type. The length of each cantilever is 20 μm. The tip of the V-shaped type is bridged by two wires with thickness of 0.6 μm. The bulk triangular type has a thickness of 1.5 μm. The frequency characteristics of the cantilevers vibrated using photothermal excitation were measured by laser Doppler velocimetry. The resonance frequency of the V-shaped type and the bulk triangular type were 687 kHz and 8.42 MHz, and their spring constants are estimated to be 0.7 N/m and 370 N/m, respectively.
Show PACS
07.10.Cm Micromechanical devices and systems
81.65.Cf Surface cleaning, etching, patterning
07.79.Lh Atomic force microscopes
81.05.Cy Elemental semiconductors
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices

Design and experimental tests of a novel neutron spin analyzer for wide angle spin echo spectrometers

Peter Fouquet, Bela Farago, Ken H. Andersen, Phillip M. Bentley, Gilles Pastrello, Iain Sutton, Eric Thaveron, Fréderic Thomas, Evgeny Moskvin, and Catherine Pappas

Rev. Sci. Instrum. 80, 095105 (2009); http://dx.doi.org/10.1063/1.3212669 (9 pages) | Cited 1 time

Online Publication Date: 9 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This paper describes the design and experimental tests of a novel neutron spin analyzer optimized for wide angle spin echo spectrometers. The new design is based on nonremanent magnetic supermirrors, which are magnetized by vertical magnetic fields created by NdFeB high field permanent magnets. The solution presented here gives stable performance at moderate costs in contrast to designs invoking remanent supermirrors. In the experimental part of this paper we demonstrate that the new design performs well in terms of polarization, transmission, and that high quality neutron spin echo spectra can be measured.
Show PACS
29.30.Hs Neutron spectroscopy

Ray tracing flux calculation for the small and wide angle x-ray scattering diffraction station at the SESAME synchrotron radiation facility

Wa'el Salah, M. Sanchez del Rio, and H. Hoorani

Rev. Sci. Instrum. 80, 095106 (2009); http://dx.doi.org/10.1063/1.3213620 (7 pages) | Cited 1 time

Online Publication Date: 9 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The calculation for the optics of the synchrotron radiation small and wide angle x-ray scattering beamline, currently under construction at SESAME is described. This beamline is based on a cylindrically bent germanium (111) single crystal with an asymmetric cut of 10.5°, followed by a 1.2 m long rhodium coated plane mirror bent into a cylindrical form. The focusing properties of bent asymmetrically cut crystals have not yet been studied in depth. The present paper is devoted to study of a particular application of a bent asymmetrically cut crystal using ray tracing simulations with the SHADOW code. These simulations show that photon fluxes of order of 1.09×1011 photons/s will be available at the experimental focus at 8.79 keV. The focused beam dimensions will be 2.2 mm horizontal full width at half maximum (FWHM) by 0.12 mm vertical (FWHM).
Show PACS
61.05.cc Theories of x-ray diffraction and scattering
41.60.Ap Synchrotron radiation
07.85.Qe Synchrotron radiation instrumentation
42.15.Dp Wave fronts and ray tracing
42.79.Bh Lenses, prisms and mirrors

A method for the temperature calibration of an infrared camera using water as a radiative source

S. M. Bower, J. Kou, and J. R. Saylor

Rev. Sci. Instrum. 80, 095107 (2009); http://dx.doi.org/10.1063/1.3213075 (7 pages)

Online Publication Date: 10 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Presented here is an effective low-cost method for the temperature calibration of infrared cameras, for applications in the 0–100 °C range. The calibration of image gray level intensity to temperature is achieved by imaging an upwelling flow of water, the temperature of which is measured with a thermistor probe. The upwelling flow is created by a diffuser located below the water surface of a constant temperature water bath. The thermistor probe is kept immediately below the surface, and the distance from the diffuser outlet to the surface is adjusted so that the deformation of the water surface on account of the flow is small, yet the difference between the surface temperature seen by the camera and the bulk temperature measured by the thermistor is also small. The benefit of this method compared to typical calibration procedures is that, without sacrificing the quality of the calibration, relatively expensive commercial blackbodies are replaced by water as the radiative source (ε ≈ 0.98 for the wavelengths considered here). A heat transfer analysis is provided, which improves the accuracy of the calibration method and also provides the user with guidance to further increases in accuracy of the method.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
06.20.F- Units and standards
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

A silicon photomultiplier readout for time of flight neutron spectroscopy with γ-ray detectors

A. Pietropaolo, G. Gorini, G. Festa, C. Andreani, M. P. De Pascale, E. Reali, F. Grazzi, and E. M. Schooneveld

Rev. Sci. Instrum. 80, 095108 (2009); http://dx.doi.org/10.1063/1.3212677 (4 pages) | Cited 3 times

Online Publication Date: 11 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of γ-detection based on the new device.
Show PACS
29.40.Wk Solid-state detectors
85.60.Ha Photomultipliers; phototubes and photocathodes
29.30.Hs Neutron spectroscopy
29.40.Mc Scintillation detectors
29.25.Dz Neutron sources

In situ measurement of gas composition changes in radio frequency plasmas using a quartz sensor

Atsushi Suzuki and Hidehiko Nonaka

Rev. Sci. Instrum. 80, 095109 (2009); http://dx.doi.org/10.1063/1.3223345 (9 pages) | Cited 3 times

Online Publication Date: 14 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A simple method using a quartz sensor (Q-sensor) was developed to observe gas composition changes in radio frequency (rf) plasmas. The output depends on the gases’ absolute pressure, molecular weight, and viscosity. The pressure-normalized quartz sensor output depends only on the molecular weight and viscosity of the gas. Consequently, gas composition changes can be detected in the plasmas if a sensor can be used in the plasmas. Influences imparted by the plasmas on the sensor, such as those by reactive particles (e.g., radicals and ions), excited species, electrons, temperature, and electric potentials during measurements were investigated to test the applicability of this quartz sensor measurement to plasma. The Q-sensor measurement results for rf plasmas with argon, hydrogen, and their mixtures are reproducible, demonstrating that the Q-sensor measurement is applicable for plasmas. In this work, pressure- and temperature-normalized Q-sensor output (NQO) were used to obtain the gas composition information of plasma. Temperature-normalization of the Q-sensor output enabled quartz sensor measurements near plasma electrodes, where the quartz sensor temperature increases. The changes in NQO agreed with results obtained by gas analysis using a quadrupole mass spectrometer. Results confirmed that the change in NQO is mainly attributable to changes in the densities and kinds of gas molecules in the plasma gas phase, not by other extrinsic influences of plasma. For argon, hydrogen, and argon-hydrogen plasmas, these changes correspond to reduction in nitrogen, production of carbon monoxide, and dissociation of hydrogen molecules, respectively. These changes in NQO qualitatively and somewhat quantitatively agreed with results obtained using gas analysis, indicting that the measurement has a potential application to obtain the gas composition in plasmas without disturbing industrial plasma processes.
Show PACS
52.70.Nc Particle measurements
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
52.25.-b Plasma properties
52.80.Pi High-frequency and RF discharges
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

An auxiliary capacitor based ultrafast drive circuit for shear piezoelectric motors

Kamalesh Chatterjee, M. C. Boyer, W. D. Wise, and E. W. Hudson

Rev. Sci. Instrum. 80, 095110 (2009); http://dx.doi.org/10.1063/1.3213619 (5 pages) | Cited 1 time

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Shear piezoelectric motors frequently require large voltage changes on very short time scales. Since piezos behave electrically as capacitors, this requires a drive circuit capable of quickly sourcing or sinking a large amount of current at high voltages. Here we describe a novel circuit design using a high voltage amplifier, transistor switching stage, and auxiliary capacitor. This circuit can drive piezoelectric motors at higher speeds and lower costs than conventional methods and with greater flexibility for computer automation. We illustrate its application in a controller for a scanning tunneling microscope coarse approach mechanism and discuss other possible applications and modifications of this circuit.
Show PACS
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
84.50.+d Electric motors
85.30.Tv Field effect devices
84.32.Tt Capacitors

A high-precision apparatus for the characterization of thermal interface materials

R. Kempers, P. Kolodner, A. Lyons, and A. J. Robinson

Rev. Sci. Instrum. 80, 095111 (2009); http://dx.doi.org/10.1063/1.3193715 (11 pages) | Cited 5 times

Online Publication Date: 17 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An apparatus has been designed and constructed to characterize thermal interface materials with unprecedented precision and sensitivity. The design of the apparatus is based upon a popular implementation of ASTM D5470 where well-characterized meter bars are used to extrapolate surface temperatures and measure heat flux through the sample under test. Measurements of thermal resistance, effective thermal conductivity, and electrical resistance can be made simultaneously as functions of pressure or sample thickness. This apparatus is unique in that it takes advantage of small, well-calibrated thermistors for precise temperature measurements (±0.001 K) and incorporates simultaneous measurement of electrical resistance of the sample. By employing precision thermometry, low heater powers and minimal temperature gradients are maintained through the meter bars, thereby reducing uncertainties due to heat leakage and changes in meter-bar thermal conductivity. Careful implementation of instrumentation to measure thickness and force also contributes to a low overall uncertainty. Finally, a robust error analysis provides uncertainties for all measured and calculated quantities. Baseline tests were performed to demonstrate the sensitivity and precision of the apparatus by measuring the contact resistance of the meter bars in contact with each other as representative low specific thermal resistance cases. A minimum specific thermal resistance of 4.68×10−6 m2 K/W was measured with an uncertainty of 2.7% using a heat transfer rate of 16.8 W. Additionally, example measurements performed on a commercially available graphite thermal interface material demonstrate the relationship between thermal and electrical contact resistance. These measurements further demonstrate repeatability in measured effective thermal conductivity of approximately 1%.
Show PACS
07.20.Dt Thermometers
47.80.Fg Pressure and temperature measurements
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
66.25.+g Thermal conduction in nonmetallic liquids
02.60.-x Numerical approximation and analysis

Development of a relaxation calorimeter for temperatures between 0.05 and 4 K

M. Brando

Rev. Sci. Instrum. 80, 095112 (2009); http://dx.doi.org/10.1063/1.3202380 (9 pages)

Online Publication Date: 21 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A detailed description of an isoperibol calorimeter for temperatures between 0.05 and 4 K is presented. The proposed setup can provide absolute values of the heat capacity C of small samples (typically 1 mg). The extremely simple design of the sample platform, based on a sapphire substrate, and the experimental setup, which makes use only of a lock-in amplifier and a temperature controller, make the construction of such a calorimeter easy and inexpensive. The thermal-relaxation method is employed, which utilizes a permanent thermal link k between the sample platform and the low-temperature bath. The temperature dependence of k(T) is shown for several platforms throughout the entire temperature range: k(T)/T is nearly constant down to 1 K, where it starts to decrease smoothly. The observed behavior is thoroughly explained by considering the thermal resistances of the platform constituents. A comparison between the values of k(T)/T for platforms based on sapphire and on silver is presented where no significant difference has been observed. Each platform can be assembled to have a particular value of k/T at 1 K. Since the sample relaxation time τ ∼ C/k, k(T) can be adjusted to C(T) to give a reasonably fast measuring time. Here, it is demonstrated how this calorimeter can be used in so-called single-shot refrigerators (3He or demagnetization cryostats), where the time for a single measurement is limited. In addition, it can be used in moderate magnetic fields B ≤ 10 T, because the platform constituents are weakly field dependent.
Show PACS
07.20.Fw Calorimeters
65.40.Ba Heat capacity

High-pressure and high-temperature differential scanning calorimeter for combined pressure-concentration-temperature measurements of hydrides

Ph. Mauron, M. Bielmann, V. Bissig, A. Remhof, and A. Züttel

Rev. Sci. Instrum. 80, 095113 (2009); http://dx.doi.org/10.1063/1.3233939 (6 pages) | Cited 1 time

Online Publication Date: 24 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The design and construction of a high-pressure (200 bar) and high-temperature (600 °C) heat-flow differential scanning calorimeter (DSC) for the in situ investigation of the hydrogenation and dehydrogenation reactions of hydrides is presented. In combination with a pressure-concentration-temperature (pcT) system, simultaneous thermodynamic and volumetric measurements become accessible. Due to the high thermal conductivity of hydrogen, only the sample cell and the reference cell are exposed to hydrogen and the remaining system is under ambient conditions. This separation has the advantage that the calibration factor is independent of the hydrogen pressure. The internal empty volume of the combined system is as low as possible to maximize the precision of the pcT measurements. The calorimetric block of the DSC is designed with a silver/copper alloy and the temperature measurements are made resistively with platinum temperature sensors (Pt 100). The instrument was calibrated and its operability was successfully studied on the example of the hydrogen sorption behavior of LaNi5.
Show PACS
62.50.-p High-pressure effects in solids and liquids
81.70.Pg Thermal analysis, differential thermal analysis (DTA), differential thermogravimetric analysis
81.40.Vw Pressure treatment
66.70.Lm Other systems such as ionic crystals, molecular crystals, nanotubes, etc.
84.60.Ve Energy storage systems, including capacitor banks
68.43.Mn Adsorption kinetics
07.20.Fw Calorimeters

Measuring the cantilever-position-sensitive detector distance and cantilever curvature for cantilever sensor applications

Meng Xu, Ye Tian, M. L. Coates, and L. Y. Beaulieu

Rev. Sci. Instrum. 80, 095114 (2009); http://dx.doi.org/10.1063/1.3233918 (6 pages) | Cited 2 times

Online Publication Date: 28 September 2009

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Measuring cantilever sensor deflections using an optical beam deflection system is more complicated than often assumed. The direction of the reflected beam is dependent on the surface normal of the cantilever, which in turn is dependent on the state of the cantilever. It is often assumed that the cantilever is both straight and perfectly level before the onset of sensing experiments although this assumption, especially the former, is rarely true. Failure to characterize the initial state of the cantilever can lead to irreproducibility in cantilever sensor measurements. We have developed three new methods for characterizing the initial state of the cantilever. In the first case we show how to define the initial angle of inclination β of the chip on which the cantilever is attached. This method was tested using an aluminum block with a known angle of inclination. A new method for determining the initial distance Lo between the cantilever and the position-sensitive detector (PSD) is also presented. This parameter which behaves as an amplification factor of the PSD signal is critical for obtaining precise cantilever sensor data. Lastly, we present a method for determining the initial curvature of the cantilever which often results from depositing the sensing platform on the lever. Experiments conducted using deflected cantilevers showed the model to be accurate. The characterization methods presented in this work are simple to use, easy to implement, and can be incorporated into most cantilever sensor setups.
Show PACS
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
07.10.Cm Micromechanical devices and systems
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close