Review of Scientific Instruments | Volume83 Issue 5

Noniterative algorithm for improving the accuracy of a multicolor-light-emitting-diode-based colorimeter

Thu, 31 May 2012 00:00:00 EDT

Pao-Keng Yang
We present a noniterative algorithm to reliably reconstruct the spectral reflectance from discrete reflectance values measured by using multicolor light emitting diodes (LEDs) as probing light sources. The proposed algorithm estimates the spectral reflectance by a linear combination of product funct ... [Rev. Sci. Instrum. 83, 053115 (2012)] published Thu May 31, 2012.

Magnetic measurements at pressures above 10 GPa in a miniature ceramic anvil cell for a superconducting quantum interference device magnetometer

Thu, 31 May 2012 00:00:00 EDT

Naoyuki Tateiwa, Yoshinori Haga, and Tatsuma D. Matsuda et al.
A miniature ceramic anvil high pressure cell (mCAC) was earlier designed by us for magnetic measurements at pressures up to 7.6 GPa in a commercial superconducting quantum interference magnetometer [N. Tateiwa et al., Rev. Sci. Instrum. 82, 053906 (2011)]10.1063/1.3590745. Here, we describe methods ... [Rev. Sci. Instrum. 83, 053906 (2012)] published Thu May 31, 2012.

Using induced signals to sense position from a microchannel plate detector

Thu, 31 May 2012 00:00:00 EDT

R. T. deSouza, Z. Q. Gosser, and S. Hudan
We demonstrate a novel concept for a position sensitive microchannel plate detector. This detector provides sub-millimeter spatial resolution by examining the signal induced on a wire harp by the electron cloud from a microchannel plate detector. Wires in the harp are efficiently read out by couplin ... [Rev. Sci. Instrum. 83, 053305 (2012)] published Thu May 31, 2012.

Magnetostatic detection using magnetoresistive sensors with vertical motion flux modulation

Thu, 31 May 2012 00:00:00 EDT

Jiafei Hu, Mengchun Pan, and Wugang Tian et al.
Recently, the flux modulation has been presented to deal with the 1/f noise of magnetoresistive (MR) sensors. However, the efficiency of most flux modulation schemes with simple micro- electromechanical-system (MEMS) actuators is not satisfying yet. In this paper, the vertical motion flux modulation ... [Rev. Sci. Instrum. 83, 055009 (2012)] published Thu May 31, 2012.

Note: Emittance measurements of intense pulsed proton beam for different pulse length and repetition rate

Thu, 31 May 2012 00:00:00 EDT

R. Miracoli, S. Gammino, and L. Celona et al.
The high intensity ion source (SILHI), in operation at CEA-Saclay, has been used to produce a 90 mA pulsed proton beam with pulse length and repetition rates suitable for the European Spallation Source (ESS) linac. Typical r-r′ rms normalized emittance values smaller than 0.2π mm mrad have been meas ... [Rev. Sci. Instrum. 83, 056109 (2012)] published Thu May 31, 2012.

Note: Measurement of the runaway electrons in the J-TEXT tokamak

Thu, 31 May 2012 00:00:00 EDT

Z. Y. Chen, Y. Zhang, and X. Q. Zhang et al.
The runaway electrons have been measured by hard x-ray detectors and soft x-ray array in the J-TEXT tokamak. The hard x-ray radiations in the energy ranges of 0.5–5 MeV are measured by two NaI detectors. The flux of lost runaway electrons can be obtained routinely. The soft x-ray array diagnostics a ... [Rev. Sci. Instrum. 83, 056108 (2012)] published Thu May 31, 2012.

Supersonic gas jets for laser-plasma experiments

Wed, 30 May 2012 00:00:00 EDT

K. Schmid and L. Veisz
We present an in-depth analysis of De Laval nozzles, which are ideal for gas jet generation in a wide variety of experiments. Scaling behavior of parameters especially relevant to laser-plasma experiments as jet collimation, sharpness of the jet edges and Mach number of the resulting jet is studied ... [Rev. Sci. Instrum. 83, 053304 (2012)] published Wed May 30, 2012.

Geometrical factor correction in grazing incident x-ray fluorescence experiment

Tue, 29 May 2012 00:00:00 EDT

Wenbin LI, Jingtao Zhu, and Xiaoying Ma et al.
The geometrical factor in the grazing incident x-ray fluorescence analysis is an important angle-dependent term, which can have a great effect on the measured data. In this paper, the effects of the geometrical factor on the florescence yield have been demonstrated. A formula is presented to estimat ... [Rev. Sci. Instrum. 83, 053114 (2012)] published Tue May 29, 2012.

Simultaneous measurement of refractive index and temperature by integrating an external Fabry-Perot cavity with a fiber Bragg grating

Tue, 29 May 2012 00:00:00 EDT

Luan Xiong Chen, Xu Guang Huang, and Jiao Yang Li et al.
A fiber sensor for simultaneous measurements of refractive index and temperature based on the integration of a fiber Bragg grating (FBG) with an external Fabry-Perot (F-P) cavity is presented. The fringe contrast of the interference spectrum generated by the F-P cavity is used to determine the exter ... [Rev. Sci. Instrum. 83, 053113 (2012)] published Tue May 29, 2012.

Development of a novel 3-degrees of freedom flexure based positioning system

Tue, 29 May 2012 00:00:00 EDT

Hyo-Young Kim, Da-Hoon Ahn, and Dae-Gab Gweon
Flexure mechanisms have been widely used for nanometer positioning systems. This article presents a novel conceptual design of an ultra-precision 3-degrees of freedom (XYθZ) positioning system with nanometer precision. The main purpose of this novel stage design is for the application of measuremen ... [Rev. Sci. Instrum. 83, 055114 (2012)] published Tue May 29, 2012.

The thermal flash technique: The inconsequential effect of contact resistance and the characterization of carbon nanotube clusters

Tue, 29 May 2012 00:00:00 EDT

Nayandeep K. Mahanta and Alexis R. Abramson
This article presents a comprehensive mathematical treatment of the theory behind the thermal flash technique used to measure the thermal diffusivity of nanostructures. Analytical expressions predicting the temperature and its rate of change for various combinations of sample length and diffusivity ... [Rev. Sci. Instrum. 83, 054904 (2012)] published Tue May 29, 2012.

Note: A flexible light emitting diode-based broadband transient-absorption spectrometer

Fri, 25 May 2012 00:00:00 EDT

Sean M. Gottlieb, Scott C. Corley, and Dorte Madsen et al.
This Note presents a simple and flexible ns-to-ms transient absorption spectrometer based on pulsed light emitting diode (LED) technology that can be incorporated into existing ultrafast transient absorption spectrometers or operate as a stand-alone instrument with fixed-wavelength laser sources. Th ... [Rev. Sci. Instrum. 83, 056107 (2012)] published Fri May 25, 2012.

High-force NdFeB-based magnetic tweezers device optimized for microrheology experiments

Thu, 24 May 2012 00:00:00 EDT

Jun Lin and Megan T. Valentine
We present the design, calibration, and testing of a magnetic tweezers device that employs two pairs of permanent neodymium iron boron magnets surrounded by low-carbon steel focusing tips to apply large forces to soft materials for microrheology experiments. Our design enables the application of for ... [Rev. Sci. Instrum. 83, 053905 (2012)] published Thu May 24, 2012.

A Rayleigh-Brillouin scattering spectrometer for ultraviolet wavelengths

Thu, 24 May 2012 00:00:00 EDT

Ziyu Gu, M. Ofelia Vieitez, and Eric-Jan van Duijn et al.
A spectrometer for the measurement of spontaneous Rayleigh-Brillouin (RB) scattering line profiles at ultraviolet wavelengths from gas phase molecules has been developed, employing a high-power frequency-stabilized UV-laser with narrow bandwidth (2 MHz). The UV-light from a frequency-doubled titaniu ... [Rev. Sci. Instrum. 83, 053112 (2012)] published Thu May 24, 2012.

Means to remove electrode contamination effect of Langmuir probe measurement in space

Thu, 24 May 2012 00:00:00 EDT

K.-I. Oyama, C. H. Lee, and H. K. Fang et al.
Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accur ... [Rev. Sci. Instrum. 83, 055113 (2012)] published Thu May 24, 2012.

Compact inductive energy storage pulse power system

Thu, 24 May 2012 00:00:00 EDT

Senthil K, S. Mitra, and Amitava Roy et al.
An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and openi ... [Rev. Sci. Instrum. 83, 054703 (2012)] published Thu May 24, 2012.

Optimal design and fabrication of three-dimensional calibration specimens for scanning probe microscopy

Wed, 23 May 2012 00:00:00 EDT

Xiaoning Liu, Tingting Luo, and Yuhang Chen et al.
Micro-/nano-scale roughness specimens are highly demanded to synthetically calibrate the scanning probe microscopy (SPM) instrument. In this study, three-dimensional (3D) specimens with controllable main surface evaluation parameters were designed. In order to improve the design accuracy, the geneti ... [Rev. Sci. Instrum. 83, 053708 (2012)] published Wed May 23, 2012.

Four pi calibration and modeling of a bare germanium detector in a cylindrical field source

Wed, 23 May 2012 00:00:00 EDT

R. A. Dewberry and J. E. Young
In this paper we describe a 4π cylindrical field acquisition configuration surrounding a bare (unshielded, uncollimated) high purity germanium detector. We perform an efficiency calibration with a flexible planar source and model the configuration in the 4π cylindrical field. We then use exact calcu ... [Rev. Sci. Instrum. 83, 053503 (2012)] published Wed May 23, 2012.

Plasma ion source for in situ ion bombardment in a soft x-ray magnetic scattering diffractometer

Wed, 23 May 2012 00:00:00 EDT

Daniel Lengemann, Dieter Engel, and Arno Ehresmann
A new plasma ion source for in situ keV He ion bombardment of solid state samples or thin films was designed and built for ion fluences between 1 × 1012 and 1 × 1017 ions/cm2. The system was designed to be mounted to different diffraction chambers for soft x-ray resonant magnetic scattering. Without ... [Rev. Sci. Instrum. 83, 053303 (2012)] published Wed May 23, 2012.

A full Stokes vector ellipsometry measurement system for in situ diagnostics in dynamic experiments

Wed, 23 May 2012 00:00:00 EDT

L. Bakshi, S. Eliezer, and G. Appelbaum et al.
A fast ellipsometry system with a resolution of only a few nanoseconds that can simultaneously measure all four Stokes parameters was developed for use in dynamic experiments. Due to its fine temporal resolution, the system is useful for a wide variety of dynamic setups, two of which are presented, ... [Rev. Sci. Instrum. 83, 053904 (2012)] published Wed May 23, 2012.