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

Flickr Twitter iResearch App Facebook

SECTION LISTING

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Jun 1966

Volume 37, Issue 6, pp. 697-808

Page 1 of 2 Pages Next Page | Jump to Page

Phased Rotating Crystal and Chopper for Time of Flight Neutron Spectroscopy

O. K. Harling

Rev. Sci. Instrum. 37, 697 (1966); http://dx.doi.org/10.1063/1.1720299 (13 pages) | Cited 4 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A slow neutron spectrometer that uses a rotating single crystal to chop and monochromate the reactor neutron beam is described. A high transmission mechanical chopper is operated in phase with the rotating crystal to eliminate undesired crystal reflections, higher order contamination, and to suppress the background of time uncorrelated neutrons. Pulsed neutron beams of high quality can be obtained from the thermal energy range to greater than 0.5 eV. Energy widths as low as 1% with burst widths around 7 μsec can be attained at 0.3 eV. Intensities are adequate for inelastic scattering studies. The spectrometer is designed primarily for downscattering measurements. Scattering measurements are conducted in a completely shielded scattering chamber with eleven scattered neutron detectors arranged at scattering angles of 15° to 165°. Time of flight techniques are used to determine the scattered neutron spectra. The design, construction, and performance characteristics are given. Some representative measurements made on zirconium hydride are presented.

Surface Ionization Source of Cesium Ions

G. Kuskevics and B. Thompson

Rev. Sci. Instrum. 37, 710 (1966); http://dx.doi.org/10.1063/1.1720300 (3 pages) | Cited 9 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A surface ionization source using spherical powder porous tungsten generates up to 9 mA of cesium ions with only a few percent of neutral atoms.

Apparatus for Seismic Modelling Optically

Ker C. Thomson

Rev. Sci. Instrum. 37, 713 (1966); http://dx.doi.org/10.1063/1.1720301 (5 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Apparatus for the photoelastic study of propagating stress waves by a repetitive stroboscopic technique has been developed in a form suitable for seismic modelling. Using a 30 cps repetition rate the transient waves propagate forward or backward or are ``locked'' in position on the viewing screen at the control of the operator. An impact device capable of very brief contact time (1 msec) and high source strains (⅓ cm penetration) produces a very brief but intense mechanical transient. This impacter, coupled with the large size of the models used (46 cm square), permits wave propagation to be studied over a significant length of travel path, suitable for certain seismic propagation problems. Isochromatics and isoclinics of propagating waves are shown.

Quasistatic Vapor Pressure Measurements on Reactive Systems in Inert Atmosphere Box

Albert K. Fischer

Rev. Sci. Instrum. 37, 717 (1966); http://dx.doi.org/10.1063/1.1720302 (3 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
What is effectively a single tube adaptation of the quasistatic method of measuring vapor pressure has been devised. The method is suitable for use in an inert atmosphere box in studying air sensitive systems. The applicability and limits of operation of the technique are described. Precision and accuracy were checked against a known system, pure sodium.

Instrument for Measurement of Hydrogen Atom Population

D. J. Shombert, M. J. D. Low, and E. S. Argano

Rev. Sci. Instrum. 37, 720 (1966); http://dx.doi.org/10.1063/1.1720303 (2 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A transistorized Wheatstone bridge suitable for precise current or resistance measurements is described. The bridge is inexpensive, compact, and versatile, and was used for measuring hydrogen atom populations by the recombination wire probe method.

Omegatron Mass Spectrometer for Partial Pressure Measurements in Upper Atmosphere

Hasso B. Niemann and Brian C. Kennedy

Rev. Sci. Instrum. 37, 722 (1966); http://dx.doi.org/10.1063/1.1720304 (7 pages) | Cited 5 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A simple Omegatron mass analyzer used for measuring density and temperature of nitrogen in the 100 to 350 km region of the upper atmosphere has been developed. The mechanical and electrical configurations have been designed for rocket flight application, and the operating parameters optimized for the upper atmosphere measurement. This Omegatron is calibrated and flown as part of a sounding rocket experiment known as the Thermosphere Probe, which also contains an electron temperature probe for determining electron temperature and density. Several successful flights have shown that the Omegatron is a reliable device for this application.

Construction of Precision Glass Cell for Hall Coefficient Measurements of Liquids

Rudolf G. Suchannek, Learco Minghetti, and Sam Naiditch

Rev. Sci. Instrum. 37, 728 (1966); http://dx.doi.org/10.1063/1.1720305 (2 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The construction of a glass cell with rectangular cross section for measuring Hall coefficients of liquids is described. The cell can be hermetically sealed and is bakeable under vacuum. Probes for the detection of the Hall voltage have been accurately aligned by alternately grinding the holes through the cell wall and measuring their misalignment. In this way, it has been possible to reduce the misalignment of the voltage probes to half a micron or less.

Inverse Magnetic Field Readout for Superconducting Magnet Sweeps

Paul F. Sullivan

Rev. Sci. Instrum. 37, 730 (1966); http://dx.doi.org/10.1063/1.1720306 (3 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A circuit is described for driving the abscissa of an X‐Y recorder as the inverse of the magnetic field (H−1) of a superconducting solenoid. The output is independent of the sweep rate for any sweep within the range of the instrument and the error in the resultant plot is less than 0.5% of full scale for any 10 kG sweep of the magnet.

Improved Spin Wave Instability Threshold Plotter

Tom G. Purnhagen

Rev. Sci. Instrum. 37, 732 (1966); http://dx.doi.org/10.1063/1.1720307 (2 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
An improved system for plotting spin wave instability threshold data is described. The system combines analog and digital techniques and eliminates many of the drawbacks of a method previously described by the author [Rev. Sci. Instr. 35, 558 (1964)].

3He Cryostat for Operation to 0.2°K

D. Walton

Rev. Sci. Instrum. 37, 734 (1966); http://dx.doi.org/10.1063/1.1720308 (3 pages) | Cited 4 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A cryostat is described which is capable of somewhat lower operating temperatures than has previously been possible. This improvement has been achieved through the use of a pumping line to the 3He which is of larger than normal diameter, particularly at the low temperature end. Therefore, it is concluded that the major limitation in previous designs has been the pressure drop in the pumping line.

Distortion of Pulse Height Spectra by Pile‐Up Effect

J. H. Williamson

Rev. Sci. Instrum. 37, 736 (1966); http://dx.doi.org/10.1063/1.1720309 (4 pages) | Cited 4 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A method is developed to compute the distortion of pulse height distributions by the pile‐up effect for arbitrary spectra and pulse shapes. The distorted spectra can be processed by an iterative method to reproduce the original distribution. Results are given for pulses shaped by resistors and capacitors or by short circuited delay lines. The best pulse shaping network is a simple modification of the double delay line clipping amplifier.

Directional Heat Meter for Wall Shear Stress Measurements in Turbulent Boundary Layers

R. H. Drinkuth and F. J. Pierce

Rev. Sci. Instrum. 37, 740 (1966); http://dx.doi.org/10.1063/1.1720310 (2 pages) | Cited 6 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The design of a uniquely simple directional sensitive heat meter for wall shear stress measurements in turbulent boundary layers is described. Good directional and stress level resolution are shown, and the suitability of the device for three dimensional flows is discussed.

Small Neutron Beam Chopper

W. L. Whittemore

Rev. Sci. Instrum. 37, 742 (1966); http://dx.doi.org/10.1063/1.1720311 (4 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A simplified variable speed, rotating mechanical beam chopper has been developed for reactor neutron spectrum measurements, and for use in conjunction with a crystal spectrometer for inelastic neutron scattering measurements. Neutron pulses are produced with a time jitter which is small compared to the time between pulses, the rotor speed during runs of several hours being constant to at least 5%. Rotor designs for beam sizes of 1.59×4.45 cm have been successfully used for neutrons with energies up to 1.0 eV and with a transmission of about 80%.

Versatile Stopped Flow Temperature Jump Apparatus

James E. Erman and Gordon G. Hammes

Rev. Sci. Instrum. 37, 746 (1966); http://dx.doi.org/10.1063/1.1720312 (5 pages) | Cited 13 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A stopped flow temperature jump apparatus is described which permits rapid mixing of reactants and application of a temperature perturbation to the reacting system from 16 msec to several seconds or longer after mixing. The apparatus consists of a flow system with a rectangular observation chamber 1 cm in length. Electrodes are fixed above and below the observation chamber. A stopping syringe activates the time delay, switching, and triggering circuits. The triggering circuit discharges a high voltage capacitor through the solution in the observation chamber, producing a 5°K temperature jump in about 50 μsec. The response of the reacting system is monitored with absorption spectrophotometry.

Superconducting Bearing

B. Daniels and P. W. Matthews

Rev. Sci. Instrum. 37, 750 (1966); http://dx.doi.org/10.1063/1.1720313 (4 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A superconducting bearing is described which depends for its operation on the conservation of the fluxoid in a closed loop of superconductor. In operation this bearing is identical with the well‐known Beams magnetic suspension, except that the function of the servomechanism is performed automatically by the superconducting loop. The observed load characteristic of the present bearing is compared with theoretical predictions, and a practical rotor is described.

Demountable High Power Source for Soft X‐Ray Region

Richard D. Deslattes and Bert G. Simson

Rev. Sci. Instrum. 37, 753 (1966); http://dx.doi.org/10.1063/1.1720314 (2 pages) | Cited 21 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A demountable x‐ray source capable of operation up to 3 kW is described. Construction is largely of stainless steel with elastomer seals. The source is of use in exciting secondary spectra and producing bremsstrahlung for absorption studies.

Computer Designed 805 MHz Proton Linac Cavities

Harry C. Hoyt, Dennis D. Simmonds, and Walter F. Rich

Rev. Sci. Instrum. 37, 755 (1966); http://dx.doi.org/10.1063/1.1720315 (8 pages) | Cited 16 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A numerical mesh calculation which computes the fields and frequency for a resonant cavity has been developed. Fields for any cavity which has cylindrical symmetry, and for which the magnetic field has only a θ component, can be computed. The program has been used on the IBM 7094 to study 805 MHz proton linac cavities. These design studies have shown that cavities having curved walls and triangular drift tubes give improved performance. Calculated values of ``shunt impedance'' per unit length ZT2 for such cavities range from 32.4 MΩ∕m at β=v∕c=0.45 to 53.0 MΩ∕m at β=1. Experimental measurements have verified the calculations.

Technique for Measuring Megagauss Magnetic Fields Using Zeeman Effect

W. B. Garn, R. S. Caird, D. B. Thomson, and C. M. Fowler

Rev. Sci. Instrum. 37, 762 (1966); http://dx.doi.org/10.1063/1.1720316 (6 pages) | Cited 11 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Rapidly varying magnetic fields with peak values in the range from 1 to 5 MG are measured by use of a sweeping image spectrographic method. Atomic spectral lines from an exploding wire light source situated in the experimental region are recorded as the magnetic field varies in a few microseconds from a moderate initial value of a few tens of kilogauss to the peak values. Field measurements are generally accurate to within 2–3% as determined by the consistency of measurements made from several different spectral lines. The sodium D lines and the indium I 4102 Å line have proven to be exceptionally useful for field determinations. The highest field determined to date by this method is 5.1 MG, corresponding to a measured separation of 164 Å between the centers of the shorter and longer wavelength doublets which the NaD lines assume in very high fields. The doublets, of approximately 4 Å separation, are not themselves resolved.

Modified Diaphragm Pressure Gauge for Corrosive Gases

Irving Sheft

Rev. Sci. Instrum. 37, 767 (1966); http://dx.doi.org/10.1063/1.1720317 (2 pages) | Cited 3 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The Booth‐Cromer diaphragm gauge has been modified to use a linear variable differential transformer to detect the position of the diaphragm. The sensitivity of the unit is 0.01 mm Hg. The ruggedness and simplicity of the original gauge are retained.

System for Suppressing Large, Nonstatistical Noise Bursts in Digital Averaging

L. S. Goodman and F. O. Salter

Rev. Sci. Instrum. 37, 769 (1966); http://dx.doi.org/10.1063/1.1720318 (3 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A device which eliminates the effect of noise bursts that exceed the average signal rate of digital data by more than a chosen, preset amount has been designed, constructed, and is herein described.

Electron Microscope Camera with Fiber Optic Output

E. G. Burroughs and A. J. Kennedy

Rev. Sci. Instrum. 37, 771 (1966); http://dx.doi.org/10.1063/1.1720319 (2 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The design and performance of an electron microscope camera with fiber optic output is described. A line resolution of 30–35 line pairs per millimeter was obtained on the negative of the Polaroid type 55 P∕N film. The general features described may be helpful in developing an adaptation for other instruments.

Calibration of Torsion Wires and Spurious Forces in Torsion Knudsen Effusion Recoil Measurements

Robert D. Freeman and Paul D. Gwinup

Rev. Sci. Instrum. 37, 773 (1966); http://dx.doi.org/10.1063/1.1720320 (3 pages) | Cited 2 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Within an experimental error of ∼0.3% the static and the dynamic torsion constants of selected small tungsten wires are equal. It is suggested that spurious forces which have been observed in torsion Knudsen effusion recoil measurements arise from thermomolecular flow rather than from torsionally anisotropic wires.

Probe for Measuring Ion Density in Slightly Ionized, High Speed Flow

P. C. T. De Boer

Rev. Sci. Instrum. 37, 775 (1966); http://dx.doi.org/10.1063/1.1720321 (11 pages) | Cited 7 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A probe made of a hollow glass cylinder is placed with its axis parallel to a slightly ionized, high speed flow. Biased electrodes on the inside surface collect the ions and the electrons entering the probe. The charged particle density is obtained by dividing the collection current by the product of the probe entrance area, the gas velocity, and the charge per particle. In order to establish that all charged particles entering the probe are collected, it is verified that no particles are attracted by a pair of auxiliary electrodes downstream of the main ones. Proper functioning also requires negligible charged particle production inside the probe, and furthermore that the velocity of the charged particles at the probe entrance be equal to the flow velocity. The probe was used to obtain ion density profiles behind shock waves of Mach numbers 6 to 9 in air at initial pressures of 50 to 400 μ Hg. Ion densities measured were in the range 107 to 1010 cm−3. Above this range, total collection was prevented by space charge effects. The equilibrium ion densities measured are in satisfactory agreement with theory. The values obtained for the ionization relaxation time are probably influenced by the presence of impurities.
back to top
RSS Feeds

High Brilliance Light Pulses Obtained with Ordinary Arc Lamps

S. Martellucci and E. Penco

Rev. Sci. Instrum. 37, 786 (1966); http://dx.doi.org/10.1063/1.1720322 (2 pages) | Cited 2 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Abstract Unavailable

Suggested Thermometer for Low Temperatures Using Nyquist Noise and Correlator‐Amplifier

F. J. Shore and R. S. Williamson

Rev. Sci. Instrum. 37, 787 (1966); http://dx.doi.org/10.1063/1.1720323 (2 pages) | Cited 3 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Abstract Unavailable
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close