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

Flickr Twitter UniPHY Group iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Next Issue

Jan 2012

Volume 83, Issue 1, Articles (01xxxx)

Issue Cover Spotlight Figure

Rev. Sci. Instrum. 83, 011301 (2012); http://dx.doi.org/10.1063/1.3674173 (12 pages)

Joshua A. Dijksman, Frank Rietz, Kinga A. Lőrincz, Martin van Hecke, and Wolfgang Losert

In a dense, submersed packing of particles (left), a thin laser sheet and a fluorescent dye make the packing structure visible (right, laser light overlaid).  This simple principle allows for a detailed study of structure and flow behavior of dense granular materials. Image created by Felice Frankel and JAD.

Enlarge Image | Read More
Page 1 of 4 Pages Next Page | Jump to Page
back to top
RSS Feeds

Invited Article: Refractive index matched scanning of dense granular materials

Joshua A. Dijksman, Frank Rietz, Kinga A. Lőrincz, Martin van Hecke, and Wolfgang Losert

Rev. Sci. Instrum. 83, 011301 (2012); http://dx.doi.org/10.1063/1.3674173 (12 pages)

Online Publication Date: 24 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We review an experimental method that allows to probe the time-dependent structure of fully three-dimensional densely packed granular materials and suspensions by means of particle recognition. The method relies on submersing a granular medium in a refractive index matched fluid. This makes the resulting suspension transparent. The granular medium is then visualized by exciting, layer by layer, the fluorescent dye in the fluid phase. We collect references and unreported experimental know-how to provide a solid background for future development of the technique, both for new and experienced users.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
82.70.Kj Emulsions and suspensions
78.55.Bq Liquids
back to top
RSS Feeds
back to top Optics; Atoms and Molecules; Spectroscopy; Photon Detectors

Measurement of phase retardation of waveplate online based on laser feedback

Wenxue Chen, Haohao Li, Shulian Zhang, and Xingwu Long

Rev. Sci. Instrum. 83, 013101 (2012); http://dx.doi.org/10.1063/1.3673641 (3 pages)

Online Publication Date: 3 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polarization flipping accompanying with intensity transfer between two eigenstates of one laser mode happens when waveplate is placed in external cavity. The position of polarization flipping of two eigenstates is a function of phase retardation of waveplate. Phase retardation of waveplate is measured through analyzing the position of polarization flipping of two eigenstates. The measurement accuracy of phase retardation is 0.22°. A new structure of optical cement tray which can eliminate stress birefringence from optical cement process is invented. The accuracy of waveplate manufacture can be improved greatly based on the work of this article.
Show PACS
07.60.-j Optical instruments and equipment
42.79.Ci Filters, zone plates, and polarizers

High-precision laser-assisted absolute determination of x-ray diffraction angles

K. Kubiček, J. Braun, H. Bruhns, J. R. Crespo López-Urrutia, P. H. Mokler, and J. Ullrich

Rev. Sci. Instrum. 83, 013102 (2012); http://dx.doi.org/10.1063/1.3662412 (8 pages)

Online Publication Date: 4 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A novel technique for absolute wavelength determination in high-precision crystal x-ray spectroscopy recently introduced has been upgraded reaching unprecedented accuracies. The method combines visible laser beams with the Bond method, where Bragg angles (θ and −θ) are determined without any x-ray reference lines. Using flat crystals this technique makes absolute x-ray wavelength measurements feasible even at low x-ray fluxes. The upgraded spectrometer has been used in combination with first experiments on the 1s2p 1P1 → 1s2 1S0 w- line in He-like argon. By resolving a minute curvature of the x-ray lines the accuracy reaches there the best ever reported value of 1.5 ppm. The result is sensitive to predicted second-order QED contributions at the level of two-electron screening and two-photon radiative diagrams and will allow for the first time to benchmark predicted binding energies for He-like ions at this level of precision.
Show PACS
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
29.30.Kv X- and γ-ray spectroscopy

Fast magneto-optical spectrometry by spectrometer

G. X. Du, S. Saito, and M. Takahashi

Rev. Sci. Instrum. 83, 013103 (2012); http://dx.doi.org/10.1063/1.3673638 (5 pages)

Online Publication Date: 9 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time efficient measurement of the spectroscopic magneto-optical (MO) activity of materials has always been desirable. In conventional MO systems, the monochromator produces quasi-monochromatic light in a narrow wavelength window. Therefore, to measure the spectroscopic MO activity, a large number of measurements over the full spectra is required to obtain satisfactory wavelength resolution and thus is very time consuming. Here, we develop a novel system that is capable of fast measurement of the MO activity by only one white light source, two polarizers, one achromatic quarter-wave plate, and one spectrometer. This system is flexible from UV to IR region, only depending on the power spectra of light source and sensitivity of the detector at the corresponding wavelengths. As examples, we measured the intriguing optic and MO activity in glass, ferromagnetic thin film, and bulk GaAs in the visible to near infrared region. The results of glass demonstrated a minimum resolvable Faraday rotation angle of 0.004° by the currently equipped system.
Show PACS
07.60.Rd Visible and ultraviolet spectrometers
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
78.20.Ls Magneto-optical effects
85.60.Gz Photodetectors (including infrared and CCD detectors)
42.79.Ci Filters, zone plates, and polarizers

Fully programmable single-photon detection module for InGaAs/InP single-photon avalanche diodes with clean and sub-nanosecond gating transitions

Alberto Tosi, Adriano Della Frera, Andrea Bahgat Shehata, and Carmelo Scarcella

Rev. Sci. Instrum. 83, 013104 (2012); http://dx.doi.org/10.1063/1.3675579 (8 pages)

Online Publication Date: 10 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the design and characterization of a modern near-infrared photon counting module, able to exploit the best performance of InGaAs/InP single-photon avalanche diodes for the detection of fast and faint optical signals up to 1.7 μm. Such instrument is suitable for many applications, thanks to the user-friendly interface and the fully adjustable settings of all operating parameters. We extensively characterized both the electronics and the detector, and we validated such instrument up to 133 MHz gate repetition frequency, for photon-counting and photon-timing applications, with very clean temporal response and excellent timing performance of less than 100 ps.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Dw Photodiodes; phototransistors; photoresistors

Magnetic transport apparatus for the production of ultracold atomic gases in the vicinity of a dielectric surface

S. Händel, A. L. Marchant, T. P. Wiles, S. A. Hopkins, and S. L. Cornish

Rev. Sci. Instrum. 83, 013105 (2012); http://dx.doi.org/10.1063/1.3676161 (10 pages)

Online Publication Date: 12 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present an apparatus designed for studies of atom-surface interactions using quantum degenerate gases of 85Rb and 87Rb in the vicinity of a room temperature dielectric surface. The surface to be investigated is a super-polished face of a glass Dove prism mounted in a glass cell under ultra-high vacuum. To maintain excellent optical access to the region surrounding the surface, magnetic transport is used to deliver ultracold atoms from a separate vacuum chamber housing the magneto-optical trap (MOT). We present a detailed description of the vacuum apparatus highlighting the novel design features; a low profile MOT chamber and the inclusion of an obstacle in the transport path. We report the characterization and optimization of the magnetic transport around the obstacle, achieving transport efficiencies of 70% with negligible heating. Finally, we demonstrate the loading of a hybrid optical-magnetic trap with 87Rb and the creation of Bose-Einstein condensates via forced evaporative cooling close to the dielectric surface.
Show PACS
37.10.Gh Atom traps and guides
03.75.Nt Other Bose-Einstein condensation phenomena
07.30.-t Vacuum apparatus
32.60.+i Zeeman and Stark effects
34.35.+a Interactions of atoms and molecules with surfaces

A dual-channel, focusing x-ray spectrograph with uniform dispersion for Z pinch plasmas measurement

Qingguo Yang, Zeren Li, Guanhua Chen, Yan Ye, Xianbin Huang, Hongchun Cai, Jing Li, and Shali Xiao

Rev. Sci. Instrum. 83, 013106 (2012); http://dx.doi.org/10.1063/1.3676166 (6 pages)

Online Publication Date: 19 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A dual-channel, focusing x-ray spectrograph with uniform dispersion (i.e., the linear dispersion of this spectrograph is a constant) is described for measuring the x-ray spectra emission from the hot, dense Al Z pinch plasmas. The spectrograph uses double uniform-dispersed crystals (e.g., a Quartz 1010 crystal and a Mica 002 crystal) as dispersion elements and a double-film box as detector to achieve the simultaneous recording of the time integrated spectrum covering a wide spectral range of ∼5–9 Å. Since this spectrograph disperse the x-rays on the detector plane with uniform spacing for every wavelength, it needs not the calibration of the wavelength with spatial coordinate, thereby own the advantages of easiness and veracity for spectra identification. The design of this spectrograph and the example of experiment on the “Yang” accelerator are presented.
Show PACS
52.70.-m Plasma diagnostic techniques and instrumentation
07.85.Nc X-ray and γ-ray spectrometers

An optically pumped XeF(C-A) laser with repetitive rate of 10 Hz

Yu Li, Ma Lian-ying, Yi Ai-ping, Huang Chao, Zhu Feng, An Xiao-xia, Shen Yan-long, Qian Hang, Huang Xin, Huang Ke, Tang Ying, Ye Xi-sheng, and Liu Jing-ru

Rev. Sci. Instrum. 83, 013107 (2012); http://dx.doi.org/10.1063/1.3677847 (4 pages)

Online Publication Date: 20 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A novel XeF(C-A) laser which can be operated in repetition mode has been developed based on surface discharge optical pumping technique. Its maximum repetitive rate is up to 10 Hz. The influence of repetitive rate and gas flow rate on the stability of output energy is studied and the main factor which influences the stability of output energy is analyzed. The experimental results show that increasing the gas flow rate into laser chamber can improve the stability of the output energy. The ideal output energy results of 20 laser pulses under different repetitive rates and their optimal experimental conditions are presented. Output energies of more than 4 J and better stability can be obtained when the laser device operates at 1, 2, and 5 Hz, respectively. When the gas feed rate is larger than 53 l/s, the stability of output energy is improved obviously at the repetitive rate of 10 Hz, and the average energy of 20 laser pulses is up to 3.2 J.
Show PACS
42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.By Design of specific laser systems

Positive/negative ion velocity mapping apparatus for electron-molecule reactions

Bin Wu, Lei Xia, Hong-Kai Li, Xian-Jin Zeng, and Shan Xi Tian

Rev. Sci. Instrum. 83, 013108 (2012); http://dx.doi.org/10.1063/1.3678328 (6 pages)

Online Publication Date: 20 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In molecular dissociative ionization by electron collisions and dissociative electron attachment to molecule, the respective positively and negatively charged fragments are the important products. A compact ion velocity mapping apparatus is developed for the angular distribution measurements of the positive or negative fragments produced in the electron-molecule reactions. This apparatus consists of a pulsed electron gun, a set of ion velocity mapping optic lenses, a two-dimensional position detector including two pieces of micro-channel plates, and a phosphor screen, and a charge-coupled-device camera for data acquisition. The positive and negative ion detections can be simply realized by changing the voltage polarity of ion optics and detector. Velocity sliced images can be directly recorded using a narrow voltage pulse applied on the rear micro-channel plate. The efficient performance of this system is evaluated by measuring the angular distribution of O− from the electron attachments to NO at 7.3 and 8.3 eV and O+ from the electron collision with CO at 40.0 eV.
Show PACS
42.79.Pw Imaging detectors and sensors
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)

A high accuracy femto-/picosecond laser damage test facility dedicated to the study of optical thin films

B. Mangote, L. Gallais, M. Zerrad, F. Lemarchand, L. H. Gao, M. Commandré, and M. Lequime

Rev. Sci. Instrum. 83, 013109 (2012); http://dx.doi.org/10.1063/1.3677324 (10 pages)

Online Publication Date: 23 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A laser damage test facility delivering pulses from 100 fs to 3 ps and designed to operate at 1030 nm is presented. The different details of its implementation and performances are given. The originality of this system relies the online damage detection system based on Nomarski microscopy and the use of a non-conventional energy detection method based on the utilization of a cooled CCD that offers the possibility to obtain the laser induced damage threshold (LIDT) with high accuracy. Applications of this instrument to study thin films under laser irradiation are presented. Particularly the deterministic behavior of the sub-picosecond damage is investigated in the case of fused silica and oxide films. It is demonstrated that the transition of 0–1 damage probability is very sharp and the LIDT is perfectly deterministic at few hundreds of femtoseconds. The damage process in dielectric materials being the results of electronic processes, specific information such as the material bandgap is needed for the interpretation of results and applications of scaling laws. A review of the different approaches for the estimation of the absorption gap of optical dielectric coatings is conducted and the results given by the different methods are compared and discussed. The LIDT and gap of several oxide materials are then measured with the presented instrument: Al2O3, Nb2O5, HfO2, SiO2, Ta2O5, and ZrO2. The obtained relation between the LIDT and gap at 1030 nm confirms the linear evolution of the threshold with the bandgap that exists at 800 nm, and our work expands the number of tested materials.
Show PACS
61.82.Ms Insulators
07.60.Pb Conventional optical microscopes
42.15.Eq Optical system design
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Wc Optical coatings
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)

Total internal reflection fluorescence microscopy imaging-guided confocal single-molecule fluorescence spectroscopy

Desheng Zheng, Leonora Kaldaras, and H. Peter Lu

Rev. Sci. Instrum. 83, 013110 (2012); http://dx.doi.org/10.1063/1.3677334 (5 pages)

Online Publication Date: 23 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed an integrated spectroscopy system combining total internal reflection fluorescence microscopy imaging with confocal single-molecule fluorescence spectroscopy for two-dimensional interfaces. This spectroscopy approach is capable of both multiple molecules simultaneously sampling and in situ confocal fluorescence dynamics analyses of individual molecules of interest. We have demonstrated the calibration with fluorescent microspheres, and carried out single-molecule spectroscopy measurements. This integrated single-molecule spectroscopy is powerful in studies of single molecule dynamics at interfaces of biological and chemical systems.
Show PACS
07.60.Pb Conventional optical microscopes
07.60.Rd Visible and ultraviolet spectrometers
06.20.fb Standards and calibration

Two beam surface fluctuation specular reflection spectroscopy

Allan Raudsepp, Christian Fretigny, François Lequeux, and Laurence Talini

Rev. Sci. Instrum. 83, 013111 (2012); http://dx.doi.org/10.1063/1.3678317 (7 pages)

Online Publication Date: 23 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In surface fluctuation specular reflection spectroscopy (SFSRS) deflections of a specularly reflected laser beam are used to characterize thermally excited surface waves. Here we report on a new two beam version of SFSRS in which the deflections of two reflected laser beams from separate locations on a surface are correlated. We demonstrate that this new two beam SFSRS technique can be used to determine directly the power spectrum of height fluctuation of thermally excited surface waves over a large range of both frequencies and wavevectors. In addition, we show that the technique is well suited for materials ranging from simple liquids to complex liquids and soft solids, including turbid materials.
Show PACS
42.62.Fi Laser spectroscopy

One-shot spectrometer for several elements using an integrated conical crystal analyzer

Kohei Morishita, Kouichi Hayashi, and Kazuo Nakajima

Rev. Sci. Instrum. 83, 013112 (2012); http://dx.doi.org/10.1063/1.3677326 (7 pages)

Online Publication Date: 24 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time-resolved x-ray spectrometry using an ultrastrong x-ray source such as an x-ray free electron laser is one of the new trends in the field of x-ray physics. To achieve such time-resolved measurement, the development of an one-shot spectrometer with a wide wavelength range, high efficiency, and good energy resolution is an essential prerequisite. Here we developed an integrated conical Ge crystal analyzer consisting of several conical rings, which were connected using spline surfaces to form a single body using our previously developed hot deformation technique, which can form a Si or Ge wafer into an arbitrary and accurate shape. We simultaneously focused several characteristic lines from an alloy sample onto different positions on a small x-ray charge-coupled device with very high image brightness (gain relative to planar analyzer: 100) and a good spatial resolution of 9–13 eV. The small radius of curvature of the crystal (28–50 mm) enabled us to realize a very short sample-detector distance of 214.4 mm. The present result shows the possibility of realizing a new focusing x-ray crystal spectrograph that can control the focal position as desired.
Show PACS
07.85.Nc X-ray and γ-ray spectrometers
85.30.Tv Field effect devices

Time-resolved one-dimensional detection of x-ray scattering in pulsed magnetic fields

Zahirul Islam, Jacob P. C. Ruff, Kate A. Ross, Hiroyuki Nojiri, and Bruce D. Gaulin

Rev. Sci. Instrum. 83, 013113 (2012); http://dx.doi.org/10.1063/1.3675478 (4 pages) | Cited 1 time

Online Publication Date: 25 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed an application of a one-dimensional micro-strip detector for capturing x-ray diffraction data in pulsed magnetic fields. This detector consists of a large array of 50 μm-wide Si strips with a full-frame read out at 20 kHz. Its use substantially improves data-collection efficiency and quality as compared to point detectors, because diffraction signals are recorded along an arc in reciprocal space in a time-resolved manner. By synchronizing with pulsed fields, the entire field dependence of a two-dimensional swath of reciprocal space may be determined using a small number of field pulses.
Show PACS
78.70.Ck X-ray scattering
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices

Improving metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy signals by means of a modified time-of-flight separation

Florian M. Spirkl, Sebastian Kunz, Florian F. Schweinberger, Adrian N. Farnbacher, Richard Schröter, and Ulrich Heiz

Rev. Sci. Instrum. 83, 013114 (2012); http://dx.doi.org/10.1063/1.3677648 (6 pages)

Online Publication Date: 25 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The separation of ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) is usually performed by a time-of-flight (ToF) separation using pre-set ToF for both types of signal. In this work, we present a new, improved ex situ signal separation method for the separation of MIES and UPS for every single measurement. Signal separation issues due to changes of system parameters can be overcome by changing the ToF separation and therefore allowing for the application of a wider range of measuring conditions. The method also enables to identify and achieve separation of the two signals without any time consuming calibration and the use of any special material for the calibration. Furthermore, changes made to the discharge source are described that enable to operate an existing MIES/UPS source over a broader range of conditions. This allows for tuning of the yield of UV photons and metastable rare gas atoms leading to an improved signal to noise ratio. First results of this improved setup are well in agreement with spectra reported in literature and show increased resolution and higher signal intensities for both MIE and UP spectra compared to the previous, non-optimized setup.
Show PACS
07.60.Rd Visible and ultraviolet spectrometers
07.81.+a Electron and ion spectrometers

Versatile high-repetition-rate phase-locked chopper system for fast timing experiments in the vacuum ultraviolet and x-ray spectral region

Stefan Plogmaker, Per Linusson, John H. D. Eland, Neville Baker, Erik M. J. Johansson, Håkan Rensmo, Raimund Feifel, and Hans Siegbahn

Rev. Sci. Instrum. 83, 013115 (2012); http://dx.doi.org/10.1063/1.3677329 (6 pages)

Online Publication Date: 27 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A novel light chopper system for fast timing experiments in the vacuum-ultraviolet (VUV) and x-ray spectral region has been developed. It can be phase-locked and synchronized with a synchrotron radiation storage ring, accommodating repetition rates in the range of ∼8 to ∼120 kHz by choosing different sets of apertures and subharmonics of the ring frequency (MHz range). Also the opening time of the system can be varied from some nanoseconds to several microseconds to meet the needs of a broad range of applications. Adjusting these parameters, the device can be used either for the generation of single light pulses or pulse packages from a microwave driven, continuous He gas discharge lamp or from storage rings which are otherwise often considered as quasi-continuous light sources. This chopper can be utilized for many different kinds of experiments enabling, for example, unambiguous time-of-flight (TOF) multi-electron coincidence studies of atoms and molecules excited by a single light pulse as well as time-resolved visible laser pump x-ray probe electron spectroscopy of condensed matter in the valence and core level region.
Show PACS
29.27.Eg Beam handling; beam transport
29.20.db Storage rings and colliders

Ultrahigh resolution soft x-ray emission spectrometer at BL07LSU in SPring-8

Yoshihisa Harada, Masaki Kobayashi, Hideharu Niwa, Yasunori Senba, Haruhiko Ohashi, Takashi Tokushima, Yuka Horikawa, Shik Shin, and Masaharu Oshima

Rev. Sci. Instrum. 83, 013116 (2012); http://dx.doi.org/10.1063/1.3680559 (6 pages)

Online Publication Date: 31 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An extremely high resolution flat field type slit less soft x-ray emission spectrometer has been designed and constructed for the long undulator beamline BL07LSU in SPring-8. By optimizing the ruling parameters of two cylindrical gratings, a high energy resolution ΔE < 100 meV and/or an E/ΔE ∼ 10 000 are expected for the energy range of 350 eV – 750 eV taking into account the broadening by the spatial resolution (25 μm) of a CCD detector. A coma-free operation mode proposed by Strocov et al., is also applied to eliminate both defocus and coma aberrations. The spectrometer demonstrated experimentally that E/ΔE = 10 050 and 8046 for N 1s (402.1 eV) and Mn 2p (641.8 eV) edges, respectively.
Show PACS
07.85.Nc X-ray and γ-ray spectrometers
29.30.Kv X- and γ-ray spectroscopy
42.79.Dj Gratings
back to top Particle Sources, Optics and Acceleration; Particle Detectors

Arc discharge regulation of a megawatt hot cathode bucket ion source for the experimental advanced superconducting tokamak neutral beam injector

Yahong Xie, Chundong Hu, Sheng Liu, Caichao Jiang, Jun Li, Lizhen Liang, and NBI Team

Rev. Sci. Instrum. 83, 013301 (2012); http://dx.doi.org/10.1063/1.3676655 (3 pages)

Online Publication Date: 6 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Arc discharge of a hot cathode bucket ion source tends to be unstable what attributes to the filament self-heating and energetic electrons backstreaming from the accelerator. A regulation method, which based on the ion density measurement by a Langmuir probe, is employed for stable arc discharge operation and long pulse ion beam generation. Long pulse arc discharge of 100 s is obtained based on this regulation method of arc power. It establishes a foundation for the long pulse arc discharge of a megawatt ion source, which will be utilized a high power neutral beam injection device.
Show PACS
29.27.Ac Beam injection and extraction
52.25.Kn Thermodynamics of plasmas
52.50.Gj Plasma heating by particle beams
52.55.Fa Tokamaks, spherical tokamaks
52.70.Ds Electric and magnetic measurements
52.75.Di Ion and plasma propulsion
29.25.Ni Ion sources: positive and negative

Electron spectrometer in adjustable triode configuration for photo-induced field emission measurements

B. Bornmann, S. Mingels, F. Dams, C. Prommesberger, R. Schreiner, D. Lützenkirchen-Hecht, and G. Müller

Rev. Sci. Instrum. 83, 013302 (2012); http://dx.doi.org/10.1063/1.3673475 (8 pages)

Online Publication Date: 9 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have constructed a new ultrahigh vacuum apparatus with a triode configuration for the systematic investigation of photo-induced field emission (PFE) from metallic or semiconducting cathodes. These are exposed to electric fields up to 400 MV/m and laser irradiation by means of hole or mesh gates. Cathodes and gates are in situ exchangeable and adjustable with high precision to ensure a homogeneous extraction of electrons which are partially transmitted to the fixed electron spectrometer. Its hemispherical sector analyzer provides an energy resolution limit of 8 meV. The commissioning of the measurement system has been performed with a tungsten needle. Its temperature showed up in the high-energy tail of the electron spectrum, while its work function was derived from the spectral low-energy part combined with the integral current-voltage curve. First PFE measurements on B-doped Si-tip arrays yielded a small field emission current increase under green laser illumination. A shift and splitting of the energy spectra was observed which revealed different emission regimes as well as the photosensitivity of the cathode due to carrier excitation into the conduction band. For the full exploitation of the PFE system, a tunable laser over a wide eV-range is required.
Show PACS
07.81.+a Electron and ion spectrometers
29.30.Aj Charged-particle spectrometers: electric and magnetic
29.30.Ep Charged-particle spectroscopy
41.60.Cr Free-electron lasers

A very low energy compact electron beam ion trap for spectroscopic research in Shanghai

J. Xiao, Z. Fei, Y. Yang, X. Jin, D. Lu, Y. Shen, L. Liljeby, R. Hutton, and Y. Zou

Rev. Sci. Instrum. 83, 013303 (2012); http://dx.doi.org/10.1063/1.3675575 (5 pages)

Online Publication Date: 10 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this paper, a new compact low energy electron beam ion trap, SH-PermEBIT, is reported. This electron beam ion trap (EBIT) can operate in the electron energy range of 60–5000 eV, with a current density of up to 100 A/cm2. The low energy limit of this machine sets the record among the reported works so far. The magnetic field in the central drift tube region of this EBIT is around 0.5 T, produced by permanent magnets and soft iron. The design of this EBIT allows adjustment of the electron gun's axial position in the fringe field of the central magnetic field. This turned out to be very important for optimizing the magnetic field in the region of the electron gun and particularly important for low electron beam energy operation, since the magnetic field strength is not tunable with permanent magnets. In this work, transmission of the electron beam as well as the upper limit of the electron beam width under several conditions are measured. Spectral results from test operation of this EBIT at the electron energies of 60, 315, 2800, and 4100 eV are also reported.
Show PACS
29.27.Bd Beam dynamics; collective effects and instabilities
41.75.Fr Electron and positron beams
75.50.Ww Permanent magnets

A new detector for mass spectrometry: Direct detection of low energy ions using a multi-pixel photon counter

Edward S. Wilman, Sara H. Gardiner, Andrei Nomerotski, Renato Turchetta, Mark Brouard, and Claire Vallance

Rev. Sci. Instrum. 83, 013304 (2012); http://dx.doi.org/10.1063/1.3676164 (4 pages)

Online Publication Date: 10 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new type of ion detector for mass spectrometry and general detection of low energy ions is presented. The detector consists of a scintillator optically coupled to a single-photon avalanche photodiode (SPAD) array. A prototype sensor has been constructed from a LYSO (Lu1.8Y0.2SiO5(Ce)) scintillator crystal coupled to a commercial SPAD array detector. As proof of concept, the detector is used to record the time-of-flight mass spectra of butanone and carbon disulphide, and the dependence of detection sensitivity on the ion kinetic energy is characterised.
Show PACS
29.40.Mc Scintillation detectors
29.40.Wk Solid-state detectors
07.75.+h Mass spectrometers

A new experimental setup designed for the investigation of irradiation of nanosystems in the gas phase: A high intensity mass-and-energy selected cluster beam

G. Bruny, S. Eden, S. Feil, R. Fillol, K. El Farkh, M. M. Harb, C. Teyssier, S. Ouaskit, H. Abdoul-Carime, B. Farizon, M. Farizon, and T. D. Märk

Rev. Sci. Instrum. 83, 013305 (2012); http://dx.doi.org/10.1063/1.3677845 (7 pages)

Online Publication Date: 20 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
DIAM (Dispositif d’Irradiation d’Agrégats Moléculaires) is a new experimental setup devoted to investigate processes induced by irradiation at the nanoscale. The DIAM apparatus is based on a combination of techniques including a particle beam from high-energy physics, a cluster source from molecular and cluster physics, and mass spectrometry form analytical sciences. In this paper, we will describe the first part of the DIAM apparatus that consists of an ExB double spectrometer connected to a cluster ion source based on a continuous supersonic expansion in the presence of ionizing electrons. This setup produces high intensities of energy-and-mass selected molecular cluster ion beams (1000 s of counts s−1). The performance of the instrument will be shown through measurements of 6–8 keV beams of protonated water clusters, (H2O)nH+ (n = 0–21) and mixed protonated (or deprotonated) water-pyridine cluster ions: PyrH+(H2O)n (n = 0–15), Pyr2H+ (H2O)n (n = 0–9), and (Pyr-H)+ (H2O).
Show PACS
07.75.+h Mass spectrometers
36.40.-c Atomic and molecular clusters

In situ calibration of rotating sensor coils for magnet testing

P. Arpaia, M. Buzio, G. Golluccio, and L. Walckiers

Rev. Sci. Instrum. 83, 013306 (2012); http://dx.doi.org/10.1063/1.3675578 (7 pages)

Online Publication Date: 25 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An in situ procedure for calibrating equivalent magnetic area and rotation radius of rotating coils is proposed for testing accelerator magnets shorter than the measuring coil. The procedure exploits measurements of magnetic field and mechanical displacement inside a reference quadrupole magnet. In a quadrupole field, an offset between the magnet and coil rotation axes gives rise to a dipole component in the field series expansion. The measurements of the focusing strength, the displacement, and the resulting dipole term allow the equivalent area and radius of the coil to be determined analytically. The procedure improves the accuracy of coils with large geometrical irregularities in the winding. This is essential for short magnets where the coil dimensions constrain the measurement accuracy. Experimental results on different coils measuring small-aperture permanent magnets are shown.
Show PACS
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
75.50.Ww Permanent magnets
84.32.Hh Inductors and coils; wiring
06.20.fb Standards and calibration
back to top Nuclear Physics, Fusion and Plasmas

Investigation of a high spatial resolution method based on polar coordinate maximum entropy method for analyzing electron density fluctuation data measured by laser phase contrast

K. Matsuo, H. Iguchi, S. Okamura, and K. Matsuoka

Rev. Sci. Instrum. 83, 013501 (2012); http://dx.doi.org/10.1063/1.3673636 (9 pages)

Online Publication Date: 3 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Laser phase contrast is a powerful diagnostic method to determine the spatial distribution of electron density fluctuations in magnetically confined plasmas, although its applicability depends on magnetic field configurations. The spatial resolution of fluctuations is linked with the resolution of the propagation direction that is derived from the two-dimensional spectral analysis of the wavenumber for the fluctuations. The method was applied to fluctuation measurements in a compact helical system. In order to improve the resolution of the propagation direction with a relatively small number of data points, the maximum entropy method with polar coordinates was employed. A spatial resolution of the order of 1 cm was obtained, which is satisfactory in a plasma with a 20 cm minor radius.
Show PACS
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
52.25.Gj Fluctuation and chaos phenomena
05.70.Ce Thermodynamic functions and equations of state

A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment

Young Jin Kim, Brandon Kunkler, Chen-Yu Liu, and Gerard Visser

Rev. Sci. Instrum. 83, 013502 (2012); http://dx.doi.org/10.1063/1.3676163 (9 pages)

Online Publication Date: 10 January 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have built a high precision (24-bit) data acquisition (DAQ) system capable of simultaneously sampling eight input channels for the measurement of the electric dipole moment of the electron. The DAQ system consists of two main components: a master board for DAQ control and eight individual analog-to-digital converter (ADC) boards for signal processing. This custom DAQ system provides galvanic isolation of the ADC boards from each other and the master board using fiber optic communication to reduce the possibility of ground loop pickup and attain ultimate low levels of channel cross-talk. In this paper, we describe the implementation of the DAQ system and scrutinize its performance.
Show PACS
29.85.Ca Data acquisition and sorting
Page 1 of 4 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Your Recent History Recent History Help

Recently Viewed

  1. Interface shear microrheometer with an optically driven oscillating probe particle
  2. A new nonlinear reconstruction method based on total variation regularization of neutron penumbral imaging
  3. Note: Design and construction of a simple and reliable printed circuit board-substrate Bradbury-Nielsen gate for ion mobility spectrometry
  4. Note: Direct force and ionic-current measurements on DNA in a nanocapillary
  5. Note: Light ageing with simultaneous colorimetry via fibre optics reflection spectrometry
Go to AIP Home
Copyright © American Institute of Physics
close