摘要:

A device has been developed for the direct recording in stereographic projections of pole figure data as they are supplied from a Geiger counter x‐ray diffraction apparatus. The specimen is rotated systematically in a suitable goniometer about two axes in synchronism with movements of the chart and printer on the recorder. When the diffracted intensity attains any one of seven preset levels, the printer impresses a point of corresponding color on the chart. The point is printed at the location that has the stereographic co‐ordinates of the pole of the diffracting volume. After all possible orientations of the specimen have been explored, an array of colored points will have been obtained on the chart. When contour lines are sketched through points of like color, the usual pole figure with iso‐intensity lines is obtained.

ISSN:0034-6748    

DOI:10.1063/1.1771165

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A liquid‐filled cell for measuring the dielectric strength of solids at 100 megacycles is described. The cell consists of a high‐voltage resonant circuit and a built‐in voltage measurement probe. The calibration of the voltage measurement network is fully discussed.

ISSN:0034-6748    

DOI:10.1063/1.1771166

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

The ¾‐Mev external proton beam from the 20‐inch cyclotron appeared to diverge horizontally from one point and vertically from another point. With a series of three alternately converging and diverging electro‐static lens elements of hyperbolic cross section, it was possible either to focus the external beam to a point or to make it parallel.

ISSN:0034-6748    

DOI:10.1063/1.1771168

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A simple, potentiometer‐type tensile strain indicator for testing polymers is described in detail. Presenting information which lends itself to automatic recording, the extensometer will detect true, or logarithmic, strains from 0.01 to 200 percent, at rates from 0.10 to 1000 percent per minute. In conjunction with other apparatus it can also be used to control the strain rate of the test. Direct calibration under test conditions removes the necessity for temperature compensation. Variables in the design permit considerable flexibility in the desired performance characteristics of the instrument.

ISSN:0034-6748    

DOI:10.1063/1.1771169

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

X‐ray spectrometers are described that operate on the principle of totally absorbing the energy of an individual x‐ray photon in a scintillator. Experiments with scintillators of xylene containing terphenyl, and of sodium iodide activated by thallium, show that detection efficiencies better than 80 percent and energy resolutions better than 10 percent are attainable in the x‐ray energy range from ½ to 50 Mev. Monte Carlo calculations and crude scaling laws that simplify extrapolations to other size scintillators are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1771170

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A spectrometer for measurement of microwave absorption by gases at temperatures as high as 1000°C is described. Microwaves pass through a 5‐ft nickel absorption cell. Absorption lines are modulated by Stark effect to give sensitive detection. The spectrometer has been used to study spectral lines of some alkali halides and several other high boiling point diatomic molecules between 300°C and 775°C.

ISSN:0034-6748    

DOI:10.1063/1.1771171

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A graphical computer based upon five automatic curve followers, two integrators, nine adding amplifiers, and a pen recorder was built for the transformation and combination of curves and for a simple analog computer to plot curves from equations. Heavily inked curves on 14‐in. × 17‐in. moving tables are tracked by photoelectric followers which continuously set potentiometers so that their output voltage is proportional to the curve height. The tables are positioned by voltages so that they may be made to move at a constant rate or may be individually controlled by some variable voltage. The follower output voltages may be transformed in various ways or combined algebraically with each other and used directly or indirectly through amplifiers to drive a recorder, a table, or an integrator. By this means curves may be changed in scale (linearly or nonlinearly) on either axis. Curves may be added, subtracted, multiplied, divided, or otherwise combined or operated upon in accordance with simple equations, and the result plotted in about a minute with an accuracy under favorable conditions of about ±0.02 in. Complex curves can be analyzed by fitting with algebraic combinations of simpler curves. The apparatus may be used to fit integral or differential equations to experimental data by trial adjustment of the constants. A low ac voltage increasing linearly with time represents the independent variable; the form of the equation is determined by the way in which the various units are connected and the values of constants are set by potentiometers.

ISSN:0034-6748    

DOI:10.1063/1.1771172

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Design considerations are presented for a video microwave spectrograph using Stark modulation and a crystal or bolometer detector. Crystal and source noise is explicitly included in the treatment. A detailed description of some of the equipment in use in our laboratory is given. Some of the advantages and dis‐advantages of other systems are mentioned.

ISSN:0034-6748    

DOI:10.1063/1.1771173

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A pneumatic and an electronic regulator for helium bath temperature are described. The pneumatic regulator, an automatic pressure regulating valve with large throughput, gives a simple controller suitable for regulation to a millidegree for temperatures above 1.4°K. The electronic control uses a carbon resistor for the thermometer and a heater inside the bath for the control element. Its regulation is an order of magnitude better, and it is usable at all achievable temperatures. Its theoretical analysis, circuit diagram, construction and operating details, and performance are described. Included are some general remarks and results concerning temperature regulation in He‐I and at the lambda point.

ISSN:0034-6748    

DOI:10.1063/1.1771174

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A method is described for the construction of thermocouples inside of a No. 25 hypodermic needle yet still strong enough to withstand hard use in the field. Utilization of the couples in subcutaneous temperature measurements in man and animals outdoors for approximately three years has demonstrated satisfactory operation under weather conditions varying from rain to arctic temperatures of −50°C.

ISSN:0034-6748    

DOI:10.1063/1.1771175

出版商:AIP    

年代:1954

数据来源: AIP