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Dec 1994

Volume 65, Issue 12, pp. 3611-3874

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Goddard Space Flight Center astronomical Fabry–Pérot imaging camera

Larry W. Brown, Bruce E. Woodgate, Michael M. Ziegler, Peter J. Kenny, and Ronald J. Oliversen

Rev. Sci. Instrum. 65, 3611 (1994); http://dx.doi.org/10.1063/1.1145216 (5 pages) | Cited 4 times

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An astronomical camera is described which consists of a scanning Fabry–Pérot Interferometric (FPI) system coupled to a charge coupled detector (CCD) imaging system. The Fabry–Pérot etalon equipment consists of a commercially available Queensgate system. The CCD equipment is a commercially available Photometrics system employing one of the early developmental CCD chips of the Space Telescope Imaging Spectrograph (STIS) project. The camera is controlled by a Digital Equipment Corporation Microvax II computer. Control of a filter wheel system and other housekeeping duties are done through a Kinetic Systems Camac controller commanded by the computer.
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95.75.De Photography and photometry (including microlensing techniques)
95.75.Kk Interferometry
95.55.Aq Charge-coupled devices, image detectors, and IR detector arrays

Direct visualization of the focal parameters of a high power CO2 laser beam

K. Rogozinski, S. W. C. Scott, and H. J. J. Seguin

Rev. Sci. Instrum. 65, 3616 (1994); http://dx.doi.org/10.1063/1.1144481 (5 pages)

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A diagnostic method for high power CO2 laser beams is presented. The technique features imaging of high intensity infrared radiation via the thermally induced luminosity of high velocity charcoal particles contained within an air stream. The method is particularly convenient for determination of focal position, depth of field, beam diameter, and spot size. Variations of these parameters with power level are easily observed utilizing this charcoal powder imaging method. Using this ‘‘real‐time’’ technique, focal spot size and location accuracy are ±0.1 and ±1 mm, respectively. Results are shown to be independent of micro‐particle size within specified limits. As a result, periodic, fine laser‐workpiece adjustment is now cost effective when working with high power lasers. © 1994 American Institute of Physics.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Pre‐preionization of a long optical pulse magnetic‐spiker sustainer XeCl laser

R. S. Taylor and K. E. Leopold

Rev. Sci. Instrum. 65, 3621 (1994); http://dx.doi.org/10.1063/1.1144482 (7 pages) | Cited 4 times

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A novel preionization technique which uses a surface corona discharge to produce preionization electrons for the controlled low jitter breakdown of a main corona‐gap preionizer is described. The pre‐preionization scheme has been used to reliably preionize a long optical pulse (450 ns full width at half‐maximum) XeCl laser. The laser excitation circuit is a new version of the overshoot mode of magnetic‐spiker sustainer excitation specifically designed to be simple, reliable, and capable of high repetition rate operation. © 1994 American Institute of Physics.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
52.80.Hc Glow; corona

Narrow‐line, low‐amplitude noise semiconductor laser oscillator in the 780 nm range

L. Hilico, D. Touahri, F. Nez, and A. Clairon

Rev. Sci. Instrum. 65, 3628 (1994); http://dx.doi.org/10.1063/1.1144483 (6 pages) | Cited 6 times

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We present a narrow‐band and low‐intensity noise laser oscillator around 780 nm built from a commercially available laser diode. We have stabilized the frequency of two extended cavity diode lasers on the same high finesse Fabry–Pérot cavity using a wide‐band electronic feedback loop. We have reduced the relative linewidth of the two lasers down to 570 Hz and strongly concentrated their energy: 95% in a relative bandwidth smaller than 10 kHz. The intensity noise of this device corresponds to the shot noise for Fourier frequencies larger than a few megaHertz. © 1994 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Mi Dynamical laser instabilities; noisy laser behavior
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Controllable pulse duration of a XeCl laser

Dong Hwan Kim, Hong Chu, Young Min Jhon, and Sang Sam Choi

Rev. Sci. Instrum. 65, 3634 (1994); http://dx.doi.org/10.1063/1.1144484 (5 pages)

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Long optical pulses have been generated in a XeCl excimer laser by using a simple capacitor‐transfer discharge circuit consisting of storage capacitors charged at 26 kV and discharged through the electrodes, tightly coupled to the variable small peaking capacitors. By adjusting the [HCl] concentration and capacitance ratios, the typical pulse duration (20 ns) is stretched up to 150 ns (full width at half‐maximum). The transfer behaviors of the pulse duration from short pulse to long pulse are presented and analyzed extensively by measuring the discharge voltage profile, output energy, overall efficiency, optical waveform, and pulse duration, as functions of [HCl] concentration and capacitance ratios. © 1994 American Institute of Physics.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers

New technique for compact discharge electrodes design

F. Flora and L. Mezi

Rev. Sci. Instrum. 65, 3639 (1994); http://dx.doi.org/10.1063/1.1144485 (7 pages)

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An analytical technique, based on a generalization of the Stappaerts method which takes into account asymmetry elements, is proposed for discharge electrodes designing. In particular, compact electrode profiles are proposed for laser cells with current return bars and for double‐head lasers. © 1994 American Institute of Physics.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.-v Laser optical systems: design and operation

Nanosecond transient absorption spectrophotometer with dye laser probing and computer control

Jan Jasny, Jerzy Sepit, Jerzy Karpiuk, and Janusz Gilewski

Rev. Sci. Instrum. 65, 3646 (1994); http://dx.doi.org/10.1063/1.1144486 (7 pages) | Cited 4 times

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A computer controlled apparatus for laser flash spectroscopy has been constructed. Nitrogen laser (energy 1 mJ, pulse width 1 ns) is used both for excitation of the sample and for pumping a tunable dye laser which serves as a source of monitoring light. Two different scan modes are possible: (i) a scan with a fixed wavelength of the monitoring light: the temporal evolution of the transient absorption in the range from −2 up to 100 ns can be observed by changing the length of the variable self‐compensating optical delay line, or (ii) a scan with a fixed time delay: the corresponding transient absorption in the range 380–800 nm can be measured. For illustration, the transient absorption spectrum of benzophenone in methylcyclohexane, decay curves of the singlet state of benzanthracene in ethanol in the presence of a quencher, and a ‘‘negative absorption’’ of rhodamine B in nitriles are reported. © 1994 American Institute of Physics.
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82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)
78.40.Dw Liquids
42.62.Fi Laser spectroscopy

A novel miniature spectrometer using an integrated acousto‐optic tunable filter

Xiaolu Wang, Derek E. Vaughan, Vladimir Pelekhaty, and Joy Crisp

Rev. Sci. Instrum. 65, 3653 (1994); http://dx.doi.org/10.1063/1.1145201 (4 pages) | Cited 3 times

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In this paper, a novel miniature spectrometer is described which employs an integrated‐optic acousto‐optic tunable filter (IAOTF) as the monochromatic wavelength selective element. The performance of the system is highlighted by measuring the absorption spectra of two samples in the region of 1400 to 1600 nm. In the experiment, a light emitting diode (LED) centered at a wavelength of 1530 nm, is used as the light source and spectral filtering is achieved using an IAOTF that is tunable over more than 260 nm. The device exhibits a FWHM resolution of 1.2 nm, measures 25×3×1 mm3, weighs under 1 g and requires less than 70 mW of rf drive power. This miniature spectrometer offers several attractive design features that have utilities in a variety of applications, particularly for portable analysis and operation in harsh environments. © 1994 American Institute of Physics.
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07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.60.Rd Visible and ultraviolet spectrometers
42.79.Jq Acousto-optical devices
42.82.Gw Other integrated-optical elements and systems

Automated null ellipsometer with rotating analyzer

L. Schrottke and G. Jungk

Rev. Sci. Instrum. 65, 3657 (1994); http://dx.doi.org/10.1063/1.1144487 (4 pages) | Cited 4 times

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An automated version of a spectroscopic ac null ellipsometer is described. By simultaneous variation of the angle of incidence and the polarizer azimuth, circular polarization of the reflected radiation can be obtained for any sample configuration. This state of polarization is checked by a rotating analyzer detector system with lock‐in technique, thus achieving the highest precision that is theoretically possible. The experimental details including the minimization routine (simplex method) are presented. First experiences gained with dielectric function spectra of InP show the high reproducibility and accuracy of the arrangement. From numerically calculated second derivatives the energy and type of critical interband points are determined. © 1994 American Institute of Physics.
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07.60.Fs Polarimeters and ellipsometers
77.22.Ch Permittivity (dielectric function)

Raytracing facility for soft x‐ray and vacuum ultraviolet monochromators at NSRL

Lu Lijun

Rev. Sci. Instrum. 65, 3661 (1994); http://dx.doi.org/10.1063/1.1144488 (6 pages) | Cited 2 times

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A raytracing facility for evaluating soft x‐ray and vacuum ultraviolet optics, especially synchrotron radiation monochromators and beamlines, has been reported. Such kinds of optics consist of any number of reflecting mirrors, gratings, and, if needed, stop apertures: in coplanar or orthogonal configuration; conventional, holographic, and varied line‐space gratings are available dispersing elements in design of a monochromator. Both normal and grazing incidence optics can be handled well. Point or finite sources, necessary to be setup in the raytracing process, may be used of isotropic or of Gaussian distribution. The spot diagram or grey level image simulation will be produced. Finally, an example of its applications, raytracing of a Seya–Namioka monochromator beamline at NSRL, will be presented. © 1994 American Institute of Physics.  
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41.60.Ap Synchrotron radiation
41.50.+h X-ray beams and x-ray optics
41.85.Si Particle beam collimators, monochromators

A low‐temperature total electron yield detector for x‐ray absorption fine structure spectra

K. M. Kemner, J. Kropf, and B. A. Bunker

Rev. Sci. Instrum. 65, 3667 (1994); http://dx.doi.org/10.1063/1.1144489 (3 pages) | Cited 10 times

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A design of a total electron yield detector to collect x‐ray absorption fine structure spectra between 80 K and room temperature is described. In addition, a three‐stage goniometer setup has been incorporated into the detector to facilitate manipulation of the sample. The results of simple linearity checks to investigate the detector’s electrical performance are presented. Finally, the detector’s thermal stability is discussed. © 1994 American Institute of Physics.
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07.78.+s Electron, positron, and ion microscopes; electron diffractometers
78.70.Dm X-ray absorption spectra

Nondestructive measurement of large objects with electron paramagnetic resonance: Pottery, sculpture, and jewel ornament

Motoji Ikeya, Masahiro Yamamoto, and Hiroshi Ishii

Rev. Sci. Instrum. 65, 3670 (1994); http://dx.doi.org/10.1063/1.1144490 (3 pages) | Cited 4 times

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A cylindicral cavity of TE111 mode with an aperture of 3 mm in diameter has been used to measure the electron paramagnetic resonance (EPR) spectrum of a large object placed over the aperture. EPR spectra of a precious fossil of a dinosaur tooth piece and a fossil bone of the Machikane Alligator were measured nondestructively in addition to a jadeite sculpture, a pearl and turquoise necklace, a large turmaline, a star ruby, and ceramic pottery. Thus, EPR can be a nondestructive tool to detect forgery and to test the authenticity in art as well as to allocate ancient objects in archaeological provenance study. © 1994 American Institute of Physics.
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81.70.-q Methods of materials testing and analysis
76.30.-v Electron paramagnetic resonance and relaxation

One‐dimensional scanning of moisture in porous materials with NMR

K. Kopinga and L. Pel

Rev. Sci. Instrum. 65, 3673 (1994); http://dx.doi.org/10.1063/1.1144491 (9 pages) | Cited 37 times

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A versatile and modular nuclear magnetic resonance (NMR) instrument is described that is particularly suited for the study of moisture transport in porous media such as various building materials in which moisture can give rise to several kinds of damages. Quantitative measurements of one‐dimensional moisture profiles and their time evolution can be performed on cylindrical samples having a diameter up to 20 mm with a spatial resolution better than 1 mm. Water absorption and drying experiments on various building materials demonstrate that the instrument can also be used for materials containing relatively large amounts of magnetic impurities, which until now were hardly accessible by NMR techniques. © 1994 American Institute of Physics.
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07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques
47.56.+r Flows through porous media
47.80.-v Instrumentation and measurement methods in fluid dynamics

Integrated windows‐based control system for an electron microscope

Shengyang Ruan and Oscar H. Kapp

Rev. Sci. Instrum. 65, 3682 (1994); http://dx.doi.org/10.1063/1.1144492 (7 pages) | Cited 3 times

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A Windows application has been developed for management and operation of beam instruments such as electron or ion microscopes. It provides a facility that allows an operator to manage a complicated instrument with minimal effort, primarily under mouse control. The hardware control components used on similar instruments (e.g., the scanning transmission electron microscopes in our lab), such as toggles, buttons, and potentiometers for adjustments on various scales, are all replaced by the controls of the Windows application and are addressable on a single screen. The new controls in this program (via adjustable software settings) offer speed of response and smooth operation providing tailored control of various instrument parameters. Along with the controls offering single parameter adjustment, a two‐dimensional control was developed that allows two parameters to be coupled and addressed simultaneously. This capability provides convenience for such tasks as ‘‘finding the beam’’ and directing it to a location of interest on the specimen. Using an icon‐based display, this Windows application provides better integrated and more robust information for monitoring instrument status than the indicators and meters of the traditional instrument controls. As a Windows application, this program is naturally able to share the resources of the Windows system and is thus able to link to many other applications such as our image acquisition and processing programs. Computer control provides automatic protection and instant diagnostics for the experimental instrument. This Windows application is fully functional and is in daily use to control a new type of electron microscope developed in our lab. © 1994 American Institute of Physics.
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07.78.+s Electron, positron, and ion microscopes; electron diffractometers
07.07.Tw Servo and control equipment; robots

Work function measurements using an improved thermionic projection microscope

C. H. Hinrichs, W. A. Mackie, Ira Cohen, Jack Alin, Don Schnitzler, and Ian Noel

Rev. Sci. Instrum. 65, 3689 (1994); http://dx.doi.org/10.1063/1.1144493 (8 pages) | Cited 2 times

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A quantitative thermionic projection microscope, employing computer image processing, is described. In this system, thermionic emission from a single‐crystal hemispherical cathode is projected onto a phosphor screen and the resulting image is digitized by means of a video camera. Single‐plane effective work functions for the highest emitting planes of the cathode may be measured to within a tenth of an electron volt. © 1994 American Institute of Physics.
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73.30.+y Surface double layers, Schottky barriers, and work functions
79.40.+z Thermionic emission
68.37.-d Microscopy of surfaces, interfaces, and thin films

Improved differential heterodyne interferometer for atomic force microscopy

Minoru Sasaki, Kazuhiro Hane, Shigeru Okuma, Motohito Hino, and Yoshinori Bessho

Rev. Sci. Instrum. 65, 3697 (1994); http://dx.doi.org/10.1063/1.1144494 (5 pages) | Cited 6 times

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A highly sensitive displacement sensor for atomic force microscopy is described which enables one to measure the relative displacement of the tip from a sample surface. The sensor is based on the differential heterodyne interferometer formed between the reflections from the microscope cantilever backside and the sample surface. As a result of using an optical common‐path construction, the sensor is essentially insensitive to the mechanical vibration, and achieves high stability at low frequencies, even though there are certain restrictions imposed by the reflection from the examined surface and the variable deflection mode. Images are presented demonstrating the atomic resolution of mica and graphite. © 1994 American Institute of Physics.
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68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy

The Novolever: A new cantilever for scanning force microscopy microfabricated from polymeric materials

R. Pechmann, J. M. Köhler, W. Fritzsche, A. Schaper, and T. M. Jovin

Rev. Sci. Instrum. 65, 3702 (1994); http://dx.doi.org/10.1063/1.1144495 (5 pages) | Cited 10 times

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A new force sensor element based on multilayer thin film technology and adapted for optical readout in a conventional scanning force microscope has been developed. The use of polymers as cantilever materials enables the introduction of mechanical properties otherwise not accessible with microfabrication based on Si technology. The fully batched fabricated cantilevered force transducer is based on the photoresist novolak and incorporates an integrated EBD tip. Bending experiments on microstructures indicate that the Young’s modulus of novolak is about two orders of magnitude lower than for Si. Therefore, in using a cantilever design similar to that with Si it is possible to fabricate more flexible structures from polymeric materials. The new force sensors have been tested and their performance has been evaluated on different samples. © 1994 American Institute of Physics.
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68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy

Surface diffusion measurements by digitized autocorrelation of field emission current fluctuations

J. E. Whitten and R. Gomer

Rev. Sci. Instrum. 65, 3707 (1994); http://dx.doi.org/10.1063/1.1144496 (11 pages) | Cited 4 times

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The operating criteria of analog and digital methods for obtaining field emission fluctuation autocorrelation functions for the determination of surface diffusion coefficients are discussed and the strengths and limitations of both methods pointed out. Two digital systems, one using a spiraltron for pulse counting, the other a fast phosphor‐photomultiplier combination for the same purpose, are described and test results presented. Some results obtained digitally for W self‐diffusion on W(123) and for oxygen diffusion on W(110) are presented and shown to agree with previous results obtained by the analog method. To illustrate the potential of the digital method for obtaining very small D values results for the diffusion of H on Re(1120) at 80 K are also presented. For this case τ0=13 s, and D=1×10−14 cm2 s−1. © 1994 American Institute of Physics.
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68.35.Fx Diffusion; interface formation
79.70.+q Field emission, ionization, evaporation, and desorption

Analysis of the properties of an electrostatic triplet quadrupole lens used as an electron beam transport device

M. Marynowski, W. Franzen, and M. El‐Batanouny

Rev. Sci. Instrum. 65, 3718 (1994); http://dx.doi.org/10.1063/1.1144497 (6 pages) | Cited 2 times

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The electron optical properties of an electrostatic triplet quadrupole lens used as an electron beam transport device were reexamined, both analytically and by computer simulation, in order to derive limits on the choice of the design parameters of the lens. Furthermore, computer simulation of electron trajectories through a single quadrupole lens, and comparison with experimental results obtained by other authors, have led to a graphical relation between the fringing field end correction and the aspect ratio of the lens. © 1994 American Institute of Physics.
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41.85.Ne Electrostatic lenses, septa
41.85.Ja Particle beam transport
41.75.Fr Electron and positron beams

A differential retarding potential method for improving ion‐beam kinetic energy resolution

X. Li, Y.‐L. Huang, G. D. Flesch, and C. Y. Ng

Rev. Sci. Instrum. 65, 3724 (1994); http://dx.doi.org/10.1063/1.1145217 (5 pages) | Cited 7 times

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We present a differential retarding potential (DRP) method for improving the kinetic energy resolution of a reactant ion beam for scattering experiments. This method allows ion‐molecule reaction absolute total cross‐section measurements to be performed down to thermal energies using the simple electrostatic aperture ion lenses of a tandem quadrupole mass spectrometric ion‐molecule reaction apparatus, even though the reactant ions are formed originally with a broad kinetic energy distribution. To illustrate the principle of the DRP method, examples are given for its application to reactant ion beams prepared in an electron impact ion source and in an ion‐molecule reaction ion source. © 1994 American Institute of Physics.
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82.30.Fi Ion-molecule, ion-ion, and charge-transfer reactions
82.20.Pm Rate constants, reaction cross sections, and activation energies
41.75.-i Charged-particle beams
41.85.Qg Particle beam analyzers, beam monitors, and Faraday cups

Aluminosilicate sources of Cs+ ions

P. P. Ong and T. L. Tan

Rev. Sci. Instrum. 65, 3729 (1994); http://dx.doi.org/10.1063/1.1144498 (4 pages) | Cited 7 times

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Synthetic cesium aluminosilicates in the form of β‐eucryptite (Cs2O⋅Al2O3⋅2SiO2) and spodumene (Cs2O⋅Al2O3⋅4SiO2) were used to construct thermionic emitters of Cs+ ions. Total ion emission current and purity of ion emission of Cs+ ions for these two forms of aluminosilicates were studied and compared at four different material surface temperatures over 50 h of continuous heating. In addition, the ion emission characteristics were investigated for three other compositions of cesium aluminosilicates. It was revealed that as a Cs+ ion source, β‐eucryptite gives the optimum ion emission at the temperature of 1100 °C. © 1994 American Institute of Physics.
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79.40.+z Thermionic emission
41.75.Ak Positive-ion beams

Beam‐centroid tracking instrument for ion thrusters

James E. Pollard

Rev. Sci. Instrum. 65, 3733 (1994); http://dx.doi.org/10.1063/1.1144499 (6 pages) | Cited 1 time

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Thrust vector stability for an electrostatic ion engine can be measured with improved sensitivity and time resolution by the method described here. Four double‐wire Langmuir probes, aligned in the form of a cross, are placed in the exhaust plume and are translated by a motorized positioning system to balance the currents collected along two orthogonal axes. The thrust vector position is thereby measured with an angular resolution of <0.01° and a response time of <5 s. © 1994 American Institute of Physics.
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95.55.Pe Lunar, planetary, and deep-space probes

Energy spread and ion current measurements of several ion sources

A. D. Gaus, W. T. Htwe, J. A. Brand, T. J. Gay, and M. Schulz

Rev. Sci. Instrum. 65, 3739 (1994); http://dx.doi.org/10.1063/1.1144500 (7 pages) | Cited 12 times

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Energy spread and extracted current measurements are presented for five different types of ion sources: hot cathode, cold cathode, magnetron, microwave, and electron cyclotron resonance (ECR). The measurements were performed with a 45° parallel‐plate energy analyzer with a resolution of better than 0.5 eV at 500 eV incident energy. Energy spreads ranged from 0.5 to 4 eV, while total extracted beam currents ranged from 2 to 30 μA. Beam currents due specifically to protons, 3He++ ions, and H+2 ions are also presented. The ECR and magnetron sources gave the best overall performance. These, along with the energy analyzer, are currently being used in experiments to study ion‐atom collision physics. © 1994 American Institute of Physics.
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07.77.-n Atomic, molecular, and charged-particle sources and detectors
37.20.+j Atomic and molecular beam sources and techniques
41.75.Ak Positive-ion beams
41.85.Ew Particle beam profile, beam intensity

A new atomic beam source: The ‘‘candlestick’’

Lene Vestergaard Hau, J. A. Golovchenko, and Michael M. Burns

Rev. Sci. Instrum. 65, 3746 (1994); http://dx.doi.org/10.1063/1.1145246 (5 pages) | Cited 9 times

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The design of a novel‐type of atomic beam source which provides for long term, stable operation at high emission rates is reported. The heart of the design is the ‘‘candlestick’’ where liquid source material is transported by capillary action to a localized hot emission region. A surrounding cavity kept at the melting point for the source material shields the vacuum chamber walls from this region. The atomic beam escaping from the source is collimated, and uncollimated atoms are transported back to the liquid reservoir at the bottom of the ‘‘candlestick’’ by capillary action. This design has advantages over traditional oven designs: localized heating provides for large emission rates under high vacuum conditions, collimation is combined with recycling and conservation of source material, and the use of capillarity allows any orientation of the beam source. The source has been tested with sodium, and we believe that the design is useful for a broad range of applications including thin‐film evaporation, molecular beam epitaxy, and semiconductor surface doping. With the low thermal mass of the emission section, the source could be optimized for pulsed mode operation. Furthermore, it is anticipated that the design ideas presented here could form the basis for a supersonic source with very high Mach numbers. © 1994 American Institute of Physics.
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07.77.-n Atomic, molecular, and charged-particle sources and detectors

Electron cyclotron resonance plasma in multicusp magnets with axial magnetic plugging

Mitsuru Maeda and Hiroshi Amemiya

Rev. Sci. Instrum. 65, 3751 (1994); http://dx.doi.org/10.1063/1.1144501 (5 pages) | Cited 5 times

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An electron cyclotron resonance plasma source is built by arranging SmCo magnets to form a multicusp magnetic field with axial magnetic plugging. The source is tested in H2, N2, and Ar by the microwave of 2.45 GHz in the range from 10−2 to 10−3 Pa. The discharge sustaining power is measured as a function of pressure. The plasma density, the average electron energy, and the electron energy distribution are measured by using a Langmuir probe. Plasma is obtained at pressures as low as 10−3 Pa in Ar. The average electron energy and the ion density increase with the feed microwave power. The electron energy distribution shows depletion at the low‐energy part. Ion spectra obtained in Ar show a multicharged state up to Ar8+. © 1994 American Institute of Physics.
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52.50.Dg Plasma sources
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