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

Jun 1991

Volume 62, Issue 6, pp. 1393-1674

Page 1 of 3 Pages Next Page | Jump to Page

Optical scan‐correction system applied to atomic force microscopy

R. C. Barrett and C. F. Quate

Rev. Sci. Instrum. 62, 1393 (1991); http://dx.doi.org/10.1063/1.1142506 (7 pages) | Cited 64 times

Full Text: | Download PDF

Show Abstract
Nonlinearities inherent in the piezoelectric actuators used in high‐resolution scanning probe microscopies limit the usefulness of the instruments for precision dimensional measurements of submicrometer to micrometer scale structures. These nonlinearities can result in images where the scale changes by over 40% from one region of the image to another. This paper describes a simple two‐axis optical beam displacement sensor that is used to accurately measure the (x,y) position of a piezoelectric tube scanner used in an atomic force microscope. This sensor has a noise level of 6.1 Årms over a frequency range of 0.5 Hz–1 kHz and a stability of about 200 Å over a 30‐min period. Two different methods were used to correct the scans: postimaging software image correction and real‐time feedback scan correction. The software method allows fast imaging and does not alter the control of the microscope, but requires postimaging image processing. It also loses some image information because of interpolation errors and the necessity of cropping the image to recover a rectangular image area. Feedback correction uses the sensor and a control system to accurately position the scanner for each data point of the image. This method eliminates the postprocessing of the images as well as interpolation errors, but limits the achievable scan speed and also adds the noise of the sensor and control system to the scan itself. Finally, both scan‐correction systems reduce imaging errors dramatically over conventional open‐loop piezoelectric scanners. Both linear and quadratic scan distortion are reduced to about 1%–2% of the image size.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing

A combined molecular‐beam epitaxy and scanning tunneling microscopy system

B. G. Orr, C. W. Snyder, and M. Johnson

Rev. Sci. Instrum. 62, 1400 (1991); http://dx.doi.org/10.1063/1.1142456 (4 pages) | Cited 22 times

Full Text: | Download PDF

Show Abstract
A combined molecular‐beam epitaxy and scanning tunneling microscopy system has been constructed. The design has been optimized for the study of III‐V semiconductors with the goal of examining the surface with both in situ scanning tunneling microscopy (STM) and reflection high‐energy electron diffraction (RHEED). Using this system, it is possible to quench the growth and produce real‐space images of the surface as it appeared during deposition. Measurements obtained with both RHEED and STM are presented.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)

Efficient switchless multi‐Joule TE‐CO2 laser

P. K. Bhadani, A. Sylvan, and R. G. Harrison

Rev. Sci. Instrum. 62, 1404 (1991); http://dx.doi.org/10.1063/1.1142457 (4 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Switchless mode operation of a pulse TE‐CO2 laser is reported. The system has provided an output energy of 7 J at atmospheric pressure from a discharge volume of 3 cm×3.3 cm×42 cm with an efficiency of 8%. Under long pulse loading, it has provided 3.5 J in a 5 μs pulse at an efficiency of 7% at a pressure of 500 mbar. The elimination of the high voltage switch from the main discharge circuit has resulted in a simple and inexpensive laser system.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers
42.55.Lt Gas lasers including excimer and metal-vapor lasers

Demonstration of a novel wide‐band optical signal generator by deep phase modulation in a fiber coupler

Pie‐Yau Chien and Ci‐Ling Pan

Rev. Sci. Instrum. 62, 1408 (1991); http://dx.doi.org/10.1063/1.1142458 (3 pages)

Full Text: | Download PDF

Show Abstract
A simple method for wide bandwidth optical signal generation has been realized by applying a deep phase modulation signal in a fiber coupler which acts as an all‐fiber Michelson interferometer. The output of the interferometer displays a discrete spectrum with a nearly leveled output and frequency bandwidth up to a hundred times that of the frequency of the modulation signal. In this first demonstration, we have generated frequency components up to 4 MHz (with external modulation) and 50 MHz (by direct modulation of the laser diode) respectively. Multigigahertz operation is possible in the future with wideband integrated‐optic phase modulators.
Show PACS
42.81.Qb Fiber waveguides, couplers, and arrays
07.60.Ly Interferometers

An accurate method for refractive index measurements of liquids using two Michelson laser interferometers

J. M. St‐Arnaud, J. Ge, J. Orbriot, T. K. Bose, and Ph. Marteau

Rev. Sci. Instrum. 62, 1411 (1991); http://dx.doi.org/10.1063/1.1142459 (4 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
This article describes how a thin wedge can be combined with two Michelson laser interferometers to determine precisely the refractive index of liquids. The precision of our experimental technique is such that the refractive index values obtained with this method can yield results with a statistical error of 5×10−6. The experimental refractive index values of ethanol, CCl4, toluene, benzene, and CS2 obtained by using bidistilled water as a reference are reported.
Show PACS
07.60.Hv Refractometers and reflectometers
07.60.Ly Interferometers
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Picosecond time‐resolved absorption spectrometer using a streak camera

T. Ito, M. Hiramatsu, M. Hosoda, and Y. Tsuchiya

Rev. Sci. Instrum. 62, 1415 (1991); http://dx.doi.org/10.1063/1.1142460 (5 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
A picosecond time‐resolved absorption spectrometer is described. The apparatus consisting of a probe light source, a polychromator, and a streak camera enables us to observe time‐resolved absorption spectra in the range from picoseconds to several nanoseconds, with 50 ps time resolution. The probe light has the properties of a wide range continuum spectrum from UV to near IR and is of several tens of nanoseconds in duration. Using this apparatus, with only a single laser shot, we can observe transient absorption both temporal and spectral simultaneously. This apparatus is useful for studying the primary process of photochemical dynamics.
Show PACS
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.68.+m Photography, photographic instruments; xerography
82.50.-m Photochemistry

A backpack‐portable mass spectrometer for measurement of volatile compounds in the environment

Harold F. Hemond

Rev. Sci. Instrum. 62, 1420 (1991); http://dx.doi.org/10.1063/1.1142461 (6 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
Environmental measurements of volatile pollutants and metabolic gases are preferably made in situ. In situ measurement provides immediate information to the investigator while minimizing disturbance and eliminating the need for sample collection, preservation, and transport. A self‐contained mass spectrometer, capable of being carried by one person, has been designed and built for this purpose. The instrument is based on a compact crossed‐field analyzer using a high‐energy‐product magnet and control circuitry optimized for low power consumption using a 12‐V dc primary power source. An internal, rechargeable battery can provide up to several hours of operation in the field. Provision is made to facilitate the addition of an interface, via RS‐232, to a compact battery‐operated laptop microcomputer. A variety of inlet configurations is possible, the simplest being a probe, containing a small silicone‐rubber membrane, which may be inserted into a gas‐ or water‐containing environment of interest.
Show PACS
07.75.+h Mass spectrometers
92.60.Sz Air quality and air pollution

Real‐time sampling electronics for double modulation experiments with Fourier transform infrared spectrometers

Michael J. Green, Barbara J. Barner, and Robert M. Corn

Rev. Sci. Instrum. 62, 1426 (1991); http://dx.doi.org/10.1063/1.1142462 (5 pages) | Cited 34 times

Full Text: | Download PDF

Show Abstract
A novel synchronous real‐time analog sampling method for obtaining the sum and difference interferograms in double modulation Fourier transform infrared absorption experiments is described, and the application of this sampling methodology to polarization‐modulation FTIR measurements of thin films at metal surfaces is demonstrated. A quadratic approximation of the background signal is used to calculate the difference interferogram. The demodulation of a test waveform with the real‐time sampling electronics reveals how the bandwidth limitations of previous double modulation experiments on FTIR interferometers that employed lock‐in amplifiers have been eliminated.
Show PACS
07.57.Ty Infrared spectrometers, auxiliary equipment, and techniques
07.60.Ly Interferometers
78.66.-w Optical properties of specific thin films
78.67.-n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures

An experimental apparatus to study chemisorption at surfaces by He diffractive scattering, ultraviolet photoemission, and metastable deexcitation spectroscopies

M. Canepa, C. Guarnaschelli, L. Mattera, M. Polese, S. Terreni, and D. Truffelli

Rev. Sci. Instrum. 62, 1431 (1991); http://dx.doi.org/10.1063/1.1142463 (7 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
An experimental apparatus designed to study structural and electronic properties of surfaces is described. Ultraviolet photoemission (UPS) and metastable deexcitation spectroscopies (MDS) have been implemented in order to obtain information on electronic states in the valence‐band region with different surface sensitivity. The supersonic metastable beam source is fully described and characterized by time‐of‐flight measurements while the characteristics of the apparatus have been tested in the study of the Ag(110) surface, clean and following the dissociative chemisorption of oxygen. Exploiting the surface sensitivity of MDS, measurements as function of the oxygen coverage allow a direct correlation between work function increase and the population of the s‐p bands of the substrate near the Fermi edge. Oxygen‐induced states around 7.5 eV, difficult to observe in UPS because of strong contributions from the d bands of the substrate, are also detected.
Show PACS
07.60.Rd Visible and ultraviolet spectrometers
68.43.-h Chemisorption/physisorption: adsorbates on surfaces
82.80.-d Chemical analysis and related physical methods of analysis

An environmental cell transmission electron microscope

T. C. Lee, D. K. Dewald, J. A. Eades, I. M. Robertson, and H. K. Birnbaum

Rev. Sci. Instrum. 62, 1438 (1991); http://dx.doi.org/10.1063/1.1142464 (7 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
An aperture‐limited, differentially pumped environmental cell has been developed and installed in a JEOL 4000 EX electron microscope. With this environmental cell it is possible to observe, at high spatial resolution, the detailed changes in microstructure that occur during the interaction between a solid and a gaseous environment. The cell has been pressurized to 70 Torr with H2 gas for several hours with no adverse effects on the microscope performance. While the initial tests have been performed with hydrogen gas, the materials used to construct the environmental cell can tolerate corrosive environments. The key features of the environmental cell design along with the results from some applications are presented in this paper.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
07.79.Cz Scanning tunneling microscopes
61.05.-a Techniques for structure determination
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

NMR probe for dynamic‐angle spinning

K. T. Mueller, G. C. Chingas, and A. Pines

Rev. Sci. Instrum. 62, 1445 (1991); http://dx.doi.org/10.1063/1.1142465 (8 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
We describe the design of a probe for dynamic‐angle spinning (DAS) NMR experiments, comprised of a spinning cylindrical sample holder whose axis may be reoriented rapidly between discrete directions within the bore of a superconducting magnet. This allows the refocusing of nuclear spin magnetization that evolves under anisotropic interactions such as chemical shift anisotropy and quadrupolar coupling, providing high resolution NMR spectra for quadrupolar nuclei in solid materials. The probe includes an axial air delivery system to bearing and drive jets which support and spin a rotor containing the sample. Axis reorientation is accomplished with a pulley attached to the probehead and coupled to a stepping motor outside of the magnet. The choice of motor and gear ratio is based on an analysis of the moments of inertia of the motor and load, the desired angular resolution, and simplicity of design. Control of angular accuracy and precision are discussed, as well as the efficiency of radiofrequency irradiation and detection. High resolution DAS spectra of oxygen‐17 and aluminum‐27 nuclei in polycrystalline minerals illustrate the experimental capabilities.
Show PACS
07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques
61.05.Qr Magnetic resonance techniques; Mössbauer spectroscopy (for structure determination only)

Low‐frequency nuclear magnetic resonance and nuclear quadrupole resonance spectrometer based on a dc superconducting quantum interference device

N. Q. Fan and John Clarke

Rev. Sci. Instrum. 62, 1453 (1991); http://dx.doi.org/10.1063/1.1142466 (7 pages) | Cited 15 times

Full Text: | Download PDF

Show Abstract
A sensitive spectrometer, based on a dc superconducting quantum interference device, for the direct detection of low‐frequency pulsed nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR), is described. The frequency response extends from about 10 to 200 kHz, and the recovery time after the magnetic pulse is removed is typically 50 μs. As examples, NMR spectra are shown from Pt and Cu metal powders in a magnetic field of 6 mT, and NQR spectra are shown from 2D in a tunneling methyl group and 14N in NH4ClO4.
Show PACS
07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques
85.25.Dq Superconducting quantum interference devices (SQUIDs)

Rare gas moderated electrostatic positron beam

G. R. Massoumi, N. Hozhabri, W. N. Lennard, P. J. Schultz, S. F. Baert, H. H. Jorch, and A. H. Weiss

Rev. Sci. Instrum. 62, 1460 (1991); http://dx.doi.org/10.1063/1.1142467 (4 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
An electrostatically guided positron beam which is variable in energy from 0 to 60 keV is described. A frozen inert gas (Ar, Kr, and Xe) is used as the positron moderator. The efficiency, ϵ, defined as the ratio of the number of slow positrons at the target to the number of positrons emitted by the source has been measured; the values obtained for Ar, Kr, and Xe were ϵ∼ 2.5×10−4, 1.6×10−4, and 1.1×10−4, respectively. We estimate a source/moderator efficiency of ϵm∼7.6×10−4, 4.7×10−4, and 3.0×10−4 for Ar, Kr, and Xe, respectively, which includes source effects, grid transmission, geometrical losses, and beam transport. These values are comparable to the best reported values for thin metal foil moderators. The measured ϵm is specific to the electrostatic system; significantly higher values for the same moderator should be attainable in magnetically guided beams, where higher transmission for moderators with large energy spreads is usually obtained.
Show PACS
07.77.-n Atomic, molecular, and charged-particle sources and detectors
29.27.Eg Beam handling; beam transport

A beam profile monitor for small electron beams

J. Norem

Rev. Sci. Instrum. 62, 1464 (1991); http://dx.doi.org/10.1063/1.1142468 (4 pages)

Full Text: | Download PDF


See Also: Erratum

Show Abstract
Measurement of beam properties at the foci of high energy linacs is difficult due to the small size of the waists in proposed and existing accelerators (1 nm −2 μm). This article considers the use of bremsstrahlung radiation from thin foils to measure the size and phase space density these beams using nonimaging optics. The components of the system are described, and the ultimate resolution, evaluated theoretically for the case of the Final Focus Test Beam (FFTB) at Stanford Linear Accelerator Center, is a few nm.
Show PACS
07.77.-n Atomic, molecular, and charged-particle sources and detectors
29.20.Ej Linear accelerators
41.75.Fr Electron and positron beams

Phase‐space measurement of a beam with a Maxwellian transverse velocity distribution by a finite‐width slit

M. J. Rhee and R. F. Schneider

Rev. Sci. Instrum. 62, 1468 (1991); http://dx.doi.org/10.1063/1.1142469 (3 pages)

Full Text: | Download PDF

Show Abstract
A numerical method is presented of finding the rms width and the height of a Maxwellian transverse velocity distribution from an experimentally obtained beamlet profile formed by a finite‐width slit. The results are also least‐squares fit to polynomials that can be very conveniently used in actual data analyses.
Show PACS
07.77.-n Atomic, molecular, and charged-particle sources and detectors
06.30.Gv Velocity, acceleration, and rotation
41.75.Fr Electron and positron beams

Design and performance of a cylindrical reflection mirror analyzer for low energy ion scattering studies

Yi‐sha Ku and Ching‐shen Su

Rev. Sci. Instrum. 62, 1471 (1991); http://dx.doi.org/10.1063/1.1142470 (4 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
A compact cylindrical reflection mirror analyzer for low energy ion scattering spectrometer has been designed and constructed to be used in a vacuum thin film deposition system for in situ analysis of fresh‐deposited films. The design of the energy analyzer is similar to that of the ellipsoidal mirror analyzer, consisting of an electrostatic reflection mirror of the cylindrical sector type with a mean radius of curvature of 4.0 cm and a sector angle of 70°, a high pass energy filter, and two slits. The performance of this analyzer has been tested by the scattering of Li+ ions with energies of 606, 707, and 807 eV, respectively, on Al, Ti, Co, Cu, and stainless steel samples at angles from 125° to 155°. An average energy resolution of (1)/(56) has been obtained at an energy band of 10 eV and primary ion energy of 800 eV. Better resolution is expected with a narrower energy band and a higher primary energy. In situ monitoring of thin Cu film deposited on Si substrate in Ar+ ion sputtering process has been done to show the feasibility of this system.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
41.75.Ak Positive-ion beams
41.75.Cn Negative-ion beams
81.15.Cd Deposition by sputtering

Heterodyne technique for potential modulation differentiation

F. J. D. Almeida, R. M. Morra, and R. F. Willis

Rev. Sci. Instrum. 62, 1475 (1991); http://dx.doi.org/10.1063/1.1142471 (6 pages)

Full Text: | Download PDF

Show Abstract
A potential modulation differentiation technique which uses heterodyne modulation is presented. The second derivative I″(V) of the collected current I(V) is obtained by modulating the voltage V using two synchronized signals with angular frequencies Kω0 and (K − 1)ω0, K≫1, and detecting the component of the collected current with angular frequency ω0. This technique eliminates problems caused by stray capacitively coupled signals and harmonic distortions produced by the signal generator and the preamplifiers. It can be applied to techniques in which the desired signal is the second derivative of the collected current, such as retarding field Auger electron spectroscopy, appearance potential spectroscopy, and work‐function measurements. Auger spectra obtained using a multigrid retarding field analyzer and the proposed modulation technique show that only three grids are needed rather than the four grids required in the conventional experimental setup. Furthermore, there is no need for resonant filters or neutralization (bridge) amplifiers, and the high dynamic range commercial lock‐in amplifier can be replaced by a circuit based on a single chip.
Show PACS
79.20.Fv Electron impact: Auger emission
79.20.Hx Electron impact: secondary emission
79.20.Kz Other electron-impact emission phenomena
07.50.-e Electrical and electronic instruments and components

An electron diffraction apparatus for studies on small particles in a molecular beam

B. D. Hall, M. Flüeli, D. Reinhard, J.‐P. Borel, and R. Monot

Rev. Sci. Instrum. 62, 1481 (1991); http://dx.doi.org/10.1063/1.1142472 (8 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
An electron diffraction apparatus is described that has been designed specifically for use with molecular beams containing small particles in the nanometer size range. A novel electron detection system has been developed, using linear charge coupled device imagers, which allows rapid parallel measurement of the diffraction signal in a direct electron counting mode. The apparatus also features a 100 kV electron gun and electron optics derived from a Philips EM 300 electron microscope. Details of the apparatus are presented and measurement results on small silver particles in a beam of helium carrier gas are also given; these are interpreted using an icosahedral structure for the small particles.
Show PACS
07.78.+s Electron, positron, and ion microscopes; electron diffractometers
61.05.J- Electron diffraction and scattering
85.30.Tv Field effect devices

Neutron calibration for the FRX‐C/LSM magnetic compression experiment

R. E. Chrien

Rev. Sci. Instrum. 62, 1489 (1991); http://dx.doi.org/10.1063/1.1142473 (5 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Neutron source strength and yield from field‐reversed configurations have been measured in the FRX‐C/LSM magnetic compression experiment using plastic scintillators, indium activation samples, and moderated rhodium activation counters. The calibration of these neutron detectors is complicated by the changing shape and position of the plasma and by the presence of the massive aluminum compression coils. The overall uncertainty in the neutron measurements is estimated to be 45%.
Show PACS
07.77.-n Atomic, molecular, and charged-particle sources and detectors
52.55.Pi Fusion products effects (e.g., alpha-particles, etc.), fast particle effects
52.55.Ez Theta pinch

An improved capacitive divider probe for plasma potential measurements in the Phaedrus tokamak

E. Y. Wang, D. Diebold, P. Nonn, J. Pew, W. Q. Li, P. Probert, R. Breun, R. Majeski, S. L. Yan, and N. Hershkowitz

Rev. Sci. Instrum. 62, 1494 (1991); http://dx.doi.org/10.1063/1.1142474 (4 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
High bandwidth capacitive probes are useful tools for potentials measurements in the tokamak scrape off layer. An improved capacitive divider probe design with very high frequency bandwidth is shown. The gain of this system is between 0 and −8 dB for frequencies from 0.1 Hz to more than 100 MHz, with the −3 dB point at approximately 40 MHz. The probe structure, circuits, performance, and experimental results from the Phaedrus‐T tokamak are given.
Show PACS
52.70.-m Plasma diagnostic techniques and instrumentation
52.55.Fa Tokamaks, spherical tokamaks
07.50.-e Electrical and electronic instruments and components

Plasma properties in the open‐ended region of a coaxial‐type microwave cavity

Yoshikazu Yoshida

Rev. Sci. Instrum. 62, 1498 (1991); http://dx.doi.org/10.1063/1.1142475 (6 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
A sputtering source utilizing both microwave and dc planar magnetron plasmas is described. Microwave power is introduced into the plasma by a coaxial‐type cavity. The magnetron target is placed on the open end of the inner conductor. This source produces a plasma which is well matched, stable, and can operate continuously at gas pressures from 3×10−4 to 2×10−2 Torr. Plasmas with densities greater than 1011 cm−3 are obtained at gas pressure of 10−4 Torr using a microwave power of 100 W. The deposition rate of Cu is more than 0.13 μm/min for an argon gas pressure of 3×10−4 Torr, and microwave and dc powers of 100 W, respectively. This new source has many potential uses such as sputtering, etching, and chemical vapor deposition.
Show PACS
52.80.Pi High-frequency and RF discharges
81.15.Cd Deposition by sputtering
81.65.-b Surface treatments

The high‐frequency oscillation of current and voltage in a plasma‐focus discharge device

Toshihiko Sato, Isao Ochiai, Yasuo Kato, and Seiichi Murayama

Rev. Sci. Instrum. 62, 1504 (1991); http://dx.doi.org/10.1063/1.1142476 (7 pages)

Full Text: | Download PDF

Show Abstract
The presence of a high‐frequency (≳6 MHz) oscillation in the discharge current and voltage of a plasma‐focus device is found experimentally and is explained by using equivalent circuit analyses. The occurrence of such an oscillation is attributed to the excitation of the resonant oscillation in the discharge circuit. It is also shown that the high‐frequency response of the driver circuit, which consists of a capacitor bank and cables, plays an important role in determining the high‐frequency behavior of the discharge current and voltage.
Show PACS
52.75.-d Plasma devices
52.80.Tn Other gas discharges
07.85.-m X- and γ-ray instruments

The design and calibration of a very fast current probe for short pulse measurements

Steve E. Calico, Mark T. Crawford, M. Kristiansen, and H. Krompholz

Rev. Sci. Instrum. 62, 1511 (1991); http://dx.doi.org/10.1063/1.1142477 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The design, construction, and calibration of a probe to measure fast rise, short pulse currents is described. This probe is a 60° section of a Rogowski coil that is designed to behave as a slow wave structure. The device described has nanosecond response and the output is proportional to the excitation current for approximately 70 ns.
Show PACS
07.50.-e Electrical and electronic instruments and components
07.55.-w Magnetic instruments and components
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
84.70.+p High-current and high-voltage technology: power systems; power transmission lines and cables

Output switch for a megavolt electron beam generator

J. Mathew and J. Golden

Rev. Sci. Instrum. 62, 1514 (1991); http://dx.doi.org/10.1063/1.1142478 (3 pages)

Full Text: | Download PDF

Show Abstract
An improved gas output switch for a 12 Ω, 1.2 MV electron beam generator has been developed. The previous design used a cast epoxy switch housing with an embedded field shaper electrode. The original switch design was difficult to fabricate without defects in the casting, and several replacements failed during operation. The new design employs machined acrylic pieces instead of cast epoxy, and a glycol cavity surrounds the field shaper. Electric fields around the field shaper are therefore considerably lower. The present switch has demonstrated greater reliability and superior performance.
Show PACS
07.77.-n Atomic, molecular, and charged-particle sources and detectors
29.27.Eg Beam handling; beam transport
52.75.Kq Plasma switches (e.g., spark gaps)

PC network based data acquisition system for the MT‐1M tokamak

S. Zoletnik and S. Kálvin

Rev. Sci. Instrum. 62, 1517 (1991); http://dx.doi.org/10.1063/1.1142479 (4 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
An IBM PC compatible computer network based data acquisition system for the small tokamak MT‐1M is described. The network operating system is DECnet‐DOS and the computers are connected by a thin wire ethernet cable. The tokamak measurement system is divided into subsystems which enable fast modular reconfiguration of the system. Every subsystem can manage its own data and can access data of the other subsystems as well.
Show PACS
52.55.Fa Tokamaks, spherical tokamaks
07.05.Bx Computer systems: hardware, operating systems, computer languages, and utilities
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close