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 1959

Volume 30, Issue 6, pp. 395-499

Page 1 of 2 Pages Next Page | Jump to Page

Simplified Coincidence Circuits Using Transistors and Diodes

R. H. Miller

Rev. Sci. Instrum. 30, 395 (1959); http://dx.doi.org/10.1063/1.1716639 (4 pages) | Cited 4 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The fast semiconductor diodes and transistors now available make it possible to design counting circuits which are as fast as standard fast vacuum tube circuits. A simple coincidence circuit using these devices is described. The measured threshold and resolving time characteristics are given. The circuit is free from the difficulty present in some vacuum tube circuits wherein a coincidence count can be made with a pulse below the threshold at one input if a pulse considerably above the threshold is present at another input. The changes in counting arrangements which the simplicity of these circuits permits are discussed.

New Electron Diffraction Apparatus for Continuous Recording

R. Thun

Rev. Sci. Instrum. 30, 399 (1959); http://dx.doi.org/10.1063/1.1716640 (9 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A new electron diffraction device is described which is especially suited for the investigation of diffusion problems, phase transitions, and reactions of solids with gases or other solids. It is equipped with a continuously recording camera where a 4×10 in. photoplate passes underneath a narrow slit exposed to the diffraction cone. The resulting photograph shows parallel diffraction lines instead of the usual Debye‐Scherrer rings and gives a gapless picture of the occurring structural changes which are easy to evaluate. If the sample is heated according to a known temperature‐time function, the temperature‐structure dependence may be recorded, and by moving the sample synchronously with the plate through the electron beam, one may record the geometrical distribution of different structures in an inhomogeneous sample. The latter method is especially suited for a rapid investigation of unknown binary or multicomponent phase diagrams. The device includes the following special features: deposition of the sample containing up to 3 different components by evaporation inside the specimen chamber, an attachment for monitoring the sample reflectance during runs, a rotating shutter producing wedge‐shaped sample layers, and a heatable specimen holder for use in transmission as well as in reflection. Finally, a few examples are given showing some applications of the described electron diffraction unit.

Ring Detection in a Thin‐Lens Magnetic Spectrometer

K. C. Mann and F. A. Payne

Rev. Sci. Instrum. 30, 408 (1959); http://dx.doi.org/10.1063/1.1716641 (5 pages) | Cited 2 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Ring detection has been carried out in a thin‐lens beta‐ray spectrometer by locating anthracene crystals at the ring focus of the electron trajectories. The geometry of the electron focusing has been investigated for gathering powers of 1.6, 1.1, and 0.7% at mean emission angle tangents of 0.400, 0.385, and 0.352 and the resolutions obtained have been tabulated. At a gathering power of 1.6% a line width of better than 1.37% in momentum has been achieved. A comparison of this instrument with other helical spectrometers is made.

Mass Sensitive Detector for Relativistic Electrons

L. Marshall

Rev. Sci. Instrum. 30, 412 (1959); http://dx.doi.org/10.1063/1.1716642 (3 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A mass sensitive detector for relativistic particles is proposed whose mass sensitivity increases with increasing particle energy. The counter detects synchrotron radiation emitted by relativistic particles as they travel through a high‐intensity magnetic field. The power emitted in synchrotron radiation varies inversely as the rest mass to the fourth power, and the frequency of the spectral region in which the main power is emitted varies inversely as the rest mass cubed. In 50‐cm path of a presently practicable magnetic field, 105 gauss, an electron of 1 Bev emits on the average 10 photons with a total energy of 68 kev, each of about 7 kev. This radiation when converted to visible radiation in NaI crystals is detectable by photomultipliers. In application to cosmic rays, with a steady‐state magnetic field, the counter enables specific recognition of electrons of ≥1 Bev.

Resolution of Accelerator Magnetic Analyzing Systems

Bernard L. Cohen

Rev. Sci. Instrum. 30, 415 (1959); http://dx.doi.org/10.1063/1.1716643 (4 pages) | Cited 9 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
In accelerator magnetic analyzing systems consisting of a beam analyzing system and a reaction product analyzing system, the total resolution of the system may be made, to first order, independent of target thickness or independent of the width of the beam on the target, by proper choice of target orientation angle. By proper choice of geometry, the two may be accomplished simultaneously for a given nuclear reaction, and suitable compromises give reasonably good results for a large variety of applications. In most cases, taking advantage of these effects allows an order of magnitude increase in intensity without affecting the resolution.

Wire‐Rod Spark Counters in Air

Lino Daddi and Luciano De Franceschi

Rev. Sci. Instrum. 30, 419 (1959); http://dx.doi.org/10.1063/1.1716644 (6 pages) | Cited 6 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The operating characteristics of the Rosenblum type spark counters in air are examined. A qualitative interpretation of the experimental data is given.
The advantages of the device (no background, absence of walls, detection of heavily ionizing particles only) and its disadvantages (limited reproducibility for some incidence directions, small sensitive volume), which limit its practical utilization, are reported.

Scintillation Spectrometer with an Anticoincidence Annulus of NaI(Tl)

C. C. Trail and Sol Raboy

Rev. Sci. Instrum. 30, 425 (1959); http://dx.doi.org/10.1063/1.1716645 (5 pages) | Cited 22 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
In the scintillation spectrometer described, the main detecting crystal of NaI(Tl) is enveloped by a hollow cylinder of NaI(Tl) in anticoincidence with the main crystal. This system completely suppresses the peaks associated with the escape of the two quanta from the annihilation following pair production, and it reduces the Compton background by a factor of 7 for 4.43‐Mev gamma rays and by a factor of 5 for those of 6.1 Mev.

Use of Balanced Filters for Automatic Recording X‐Ray Diffractometer

Kenzo Tanaka, Ken‐ichi Katayama, Jun‐ichi Chikawa, and Hiroshi Suita

Rev. Sci. Instrum. 30, 430 (1959); http://dx.doi.org/10.1063/1.1716646 (5 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Using balanced filters with an automatic recording x‐ray diffractometer, almost the same effect of monochromatization as with a crystal monochromator was achieved. The detection efficiency of the balanced filters method was about 30, taking the value as 100 when no filter was used. The effective resolving time of the system involving the electronic circuits was about 5 μsec using a NaI scintillation counter as a detector. The Cu‐target x‐ray tube was operated on full‐wave rectified 60 cps 40 kvp. The comparison with the other monochromatization methods is discussed.

Vacuum Adiabatic Heat Capacity Calorimeter

H. Edward O'Neal and N. W. Gregory

Rev. Sci. Instrum. 30, 434 (1959); http://dx.doi.org/10.1063/1.1716647 (5 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The design, operation, and performance of a constant heating adiabatic vacuum calorimeter, suitable for measurement of the heat capacities of corrosive, hygroscopic, easily oxidized, and slightly volatile materials in the temperature range from 50° to 460°C, are described. A sealed glass cell is used to protect the sample.

Semiautomatic Townsend Balance System

Samuel B. Garfinkel

Rev. Sci. Instrum. 30, 439 (1959); http://dx.doi.org/10.1063/1.1716648 (4 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A semiautomatic system has been developed for use with a Lindemann‐Ryerson electrometer. The system measures ionization current in the National Bureau of Standards 4π γ‐ionization chamber by the Townsend balance‐of‐charge method. Two minature semiconductor photocells, with associated electronic circuitry, are used for detecting deflections of the electrometer and for controlling the amount of compensating charge placed on the electrometer. In addition, the starting and stopping of an electronic clock is controlled by a third photocell. The system has an ultimate precision of about 0.02%.

Plateau Slopes and Pulse Characteristics of Large, High‐Pressure BF3 Counters

R. B. Mendell and S. A. Korff

Rev. Sci. Instrum. 30, 442 (1959); http://dx.doi.org/10.1063/1.1716649 (3 pages) | Cited 2 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Factors affecting the flatness of plateaus of BF3 neutron counters of large radius and at high pressure were investigated. Counters prepared using special purification techniques showed improved characteristics. Counters of cathode radius from 1.91 to 5.06 cm were filled to pressures of BF3 from 40 to 64 cm Hg, and their pulse‐height distributions were compared. Results are discussed in terms of electron attachment in BF3 and space charge effects.

Replica Method for Examining Surface Profiles

A. P. Young and B. H. Clegg

Rev. Sci. Instrum. 30, 444 (1959); http://dx.doi.org/10.1063/1.1716650 (3 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A nondestructive method for the light microscope examination of surface profiles by means of replicas has been developed. The method has been applied to the examination of the surfaces of gear teeth. Possible extension of the method to electron microscope examination of the profiles of nearly smooth surfaces is described.

Millimicrosecond Light Source

A. Whetstone

Rev. Sci. Instrum. 30, 447 (1959); http://dx.doi.org/10.1063/1.1716651 (4 pages) | Cited 7 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A fast light pulse can be produced by pulsing reverse current through a suitable silicon p‐n junction. The light covers a range of photon energies from 1 to 3 ev. The immediate application is the testing of photomultiplier tubes, and, since any number of the junctions can be pulsed simultaneously, a method is available for lining up experiments in which large numbers of scintillators and coincidence circuits are used.

Microscope Phase Fluorometer for Determining the Fluorescence Lifetimes of Fluorochromes

Benjamin D. Venetta

Rev. Sci. Instrum. 30, 450 (1959); http://dx.doi.org/10.1063/1.1716652 (8 pages) | Cited 18 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A microscope which can measure the mean fluorescence lifetimes of small fluorescent samples is described. Special emphasis is given to fluorochromes dissolved in biological solutions and bound to thin polymeric substances, such as the desoxyribonucleic acid complexes present in the nuclei of cells. Fundamentally, the method is similar to that described by physicists and physicochemists for solutions of fluorochrome only. A diffraction modulator is used to sinusoidally modulate the intensity of a high‐pressure mercury‐vapor lamp. The phase shift between the unabsorbed exciting light, passing through the microscopic sample, and the fluorescent light is related to the fluorescence lifetime by tanΔϕ=ωτ. The phase shift Δϕ is obtained differentially from the phase angles ϕ1 and ϕ2 of each microscopic light signal with respect to a third less noisy signal, the tracer signal. The principal effort has been directed toward studying the various sources of error in the fluorometer and variabilities in lifetime measurements. The data indicate that the mean fluorescence lifetime (2.7 msec) of proflavine, bound to nuclei of tumor cells and observed with a 130× oil immersion lens, can be determined with a precision of 4×10−10 sec.

Automatic Transistor Alpha Measuring Set

D. E. Thomas and J. M. Klein

Rev. Sci. Instrum. 30, 458 (1959); http://dx.doi.org/10.1063/1.1716653 (5 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
This paper describes an automatic transistor alpha measuring set which was designed for alpha curve tracing and fast acquisition of directly read values of alpha at discrete operating points on research models of junction transistors at an early stage in their fabrication. The set operates on a true null basis. Its calibration is therefore independent of normal variations of the measuring signal level, amplifier gains, and meter calibrations. Although the set described was designed primarily as an applied research tool, it is readily adaptable to automatic card punching of large masses of data or for rapid automatic selection of production transistors which meet specified limits at a discrete operating point or over a wide and continuous operating range. The automatic selection and card punching features can be combined for production quality control studies.

Automatic Adiabatic Control for Calorimeter Shields

Leslie J. Todd, Robert H. Dettre, and Donald H. Andrews

Rev. Sci. Instrum. 30, 463 (1959); http://dx.doi.org/10.1063/1.1716654 (5 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
An automatic adiabatic shield control has been constructed for a calorimeter designed to measure heat capacities and heats of fusion, using a combination of partial on‐off control coupled with an integrating device which keeps the on‐cycle equal in length to the off‐cycle. A difference thermocouple is the primary source of the control impulse. By calibrating the control with zero heat input, corrections can be made for variations from absolute adiabatic states. Measurements on test compounds indicate a reduction of error due to heat leak to less than 0.1% of the heat to the sample.

Unusually Highly Biased Gun on the Electron Microscope

F. W. Bishop

Rev. Sci. Instrum. 30, 468 (1959); http://dx.doi.org/10.1063/1.1716655 (2 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A self‐biasing arrangement is described whereby the beam current of the electron microscope is decreased to less than 5 μa. This reduction of beam current reduces the contamination rate and the heating of the specimen and at the same time improves the illumination. A further combination wherein the bias can be adjusted from the control panel is described. The smaller aperture in the condenser system which is made possible by this system reduces the angular aperture of illumination and increases the depth of focus and resolution.

Simple Method of Shunt Impedance Measurement

J. Dekleva and K. W. Robinson

Rev. Sci. Instrum. 30, 470 (1959); http://dx.doi.org/10.1063/1.1716656 (2 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A direct method for the measurement of the shunt impedance of high‐Q resonant systems is described. The shunt impedance value is deduced from a set of normalized transmitted signals which are obtained by means of a perturbation technique. The sensitivity of the method is equal to that obtained from R∕Q measurements but requires greatly simplified instrumentation and makes it possible to obtain results much more rapidly.

Use of a Silver Tube to Admit Oxygen to a Vacuum System

N. R. Whetten and J. R. Young

Rev. Sci. Instrum. 30, 472 (1959); http://dx.doi.org/10.1063/1.1716657 (2 pages) | Cited 16 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Oxygen admitted to a vacuum system through a silver tube has been analyzed with a mass spectrometer. The oxygen was found to be of high purity. A satisfactory silver tube assembly is described, and some advantages over other methods of admitting oxygen are discussed.

pH Measurements with a Glass Electrode Withstanding 1500 kg∕cm2 Hydrostatic Pressure

A. Distèche

Rev. Sci. Instrum. 30, 474 (1959); http://dx.doi.org/10.1063/1.1716658 (5 pages) | Cited 17 times

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A glass electrode can be made to withstand high hydrostatic pressure, up to 1500 kg∕cm2, by separating the inside fluid from the outside one with a layer of silicone oil acting as a liquid piston, enabling the inside and outside pressure to compensate continuously. Such a glass electrode, with two Ag☒AgCl electrodes, maintains its hydrogen electrode function at high pressure. pH changes resulting from dissociation constant shifts caused by pressure in acid and buffer solutions have been measured in good agreement with theoretical expected values for HCl, acetic acid, carbonic acid, and acetate buffer. No agreement was found for bicarbonate buffer. Phosphate buffer and sea water have also been tested. An adapted version of the cell‐assembly is planned to equip the French bathyscaphe for deep‐sea investigations.

Transistor Circuitry for Radiation Counting

Jerry R. Gilland

Rev. Sci. Instrum. 30, 479 (1959); http://dx.doi.org/10.1063/1.1716659 (6 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
The transistorized circuits described here have been developed to provide more reliable instrumentation for the experimental nuclear physicist. These devices are a pulse amplifier, a pulse‐height analyzer, a scaler, and a linear count rate meter. The basic operating principles are discussed briefly. The electrical characteristics of these instruments compare favorably with their vacuum‐tube counterparts and they have the additional advantages of improved reliability, small size, and low power consumption.

Extended Range Pirani Gauge

Alan W. Smith

Rev. Sci. Instrum. 30, 485 (1959); http://dx.doi.org/10.1063/1.1716660 (2 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A Pirani gauge has been developed which is useful from atmospheric pressure to 10−5 mm Hg. This gauge has two elements: a platinum ribbon active in the low‐pressure region and a thermistor bead active in the high‐pressure region. By a simple but unique electrical circuit, the sensitivity in the intermediate region is maintained at a high level. In any pressure region, the gauge has the optimum characteristics possible with a Pirani‐type gauge.

Simple Way of Measuring the Power of High‐Intensity Light Beams

W. F. Flood

Rev. Sci. Instrum. 30, 487 (1959); http://dx.doi.org/10.1063/1.1716661 (2 pages) | Cited 1 time

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
A simple way of measuring the absolute power of high‐intensity light beams is described which requires only the measurement of the temperature of a known mass as a function of time. Measurements are shown to be accurate within a few percent.

Rotating‐Anode X‐Ray Generator

D. A. Davies, A. McL. Mathieson, and G. M. Stiff

Rev. Sci. Instrum. 30, 488 (1959); http://dx.doi.org/10.1063/1.1716662 (4 pages)

Online Publication Date: 29 December 2004

Full Text: | Download PDF

Show Abstract
Construction of the rotating‐anode x‐ray generator was based on that of A. Taylor (1949), the main difference lying in the design of the anode and of the anode‐cathode assembly. The anode is in the form of a flat disk, ⅞ in. thick and 6 in. in diameter, with the focus on the periphery. The cathode assembly is extended to partly cover the anode. This combined anode‐cathode assembly not only greatly reduces wall‐heating due to stray electrons but also improves the electron‐optical system. With zero‐bias conditions, it has been found possible with a silicated tungsten helix of outside diameter 0.065 in. to concentrate 200 ma into a line focus 0.020×0.40 in. with nominal spread outside the focal area. The cooling system is cyclic.
back to top
RSS Feeds

Analog Computer for Magnetic Resonance Data Reduction

R. L. Collins

Rev. Sci. Instrum. 30, 492 (1959); http://dx.doi.org/10.1063/1.1716663 (1 page) | Cited 4 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