摘要:

A circuit is described which can be used for obtaining the pulse‐height distributions from scintillation counters, proportional counters, parallel‐plate counters, and other voltage pulse sources. Differential or integral curves can be plotted automatically (J. H. Parsons, ``A sweep type alpha energy analyser,'' Report No. MonC‐416, Oak Ridge, Tennessee (1947); J. H. Parsons, Proc. Inst. Radio Engrs.37,564 (1949)) by the attachment of an electronic recorder, or can be obtained manually with the use of the built‐in rate meter or an external scaler. The counting rate loss is approximately one percent per 100,000 counts per minute. The over‐all drift in pulse‐height setting, slit‐width, and counting rate zero is less than one percent per 24 hours. It will operate from any positive output amplifier whose rise time is 0.1 microsecond or greater, and whose output is limited to 100 volts.

ISSN:0034-6748    

DOI:10.1063/1.1745757

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

The apparatus described is used in the measurement of the electrical conductivity of vapor phase systems at temperatures to 400°C and pressures to 4500 psi. A small, lightly constructed, platinum‐iridium conductivity cell is enclosed in a larger, heated, steel pressure vessel. The pressure developed in the conductivity cell on heating is counterbalanced by admitting nitrogen into the pressure vessel. The direction and magnitude of the pressure differential between the vapor in the cell and the surrounding nitrogen is indicated by a meter circuit which measures the potential drop of a radiofrequency current across a variable condenser which is operated by an aneroid diaphragm on the cell. Admission and release of nitrogen is controlled manually. Measurements of the cell resistance are made by conventional ac bridge methods and are not described.

ISSN:0034-6748    

DOI:10.1063/1.1745758

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A photographic pyrometer is described that indicates apparent surface temperatures by photographing hot surfaces and correlating the variable density of the photographic negative with the apparent surface temperature. The need for critically controlled photographic and development technique is eliminated by incorporating into every photograph the images of standard targets whose apparent surface temperatures are independently determined with an optical pyrometer. The apparent temperatures of all areas of the photographed region can be determined simultaneously and instantaneously.

ISSN:0034-6748    

DOI:10.1063/1.1745759

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An internal probe technique of producing strong gamma‐nand gamma‐pactivities with a betatron is described. Sources approaching 1 millicurie in strength of Cu62have been realized. A typical specific activity of Cu62produced in a piece of half‐mil copper 2 mm×24 mm is 7 mc/g.

ISSN:0034-6748    

DOI:10.1063/1.1745760

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Modifications of the Beckman Model DU Spectrophotometer are described which allow it to record continuously emission and excitation spectra of luminescent materials as well as reflection of powders and transmission of solids by point‐by‐point methods. All the measurements can be made over the wavelength range of 2200A to 7000A. Performance of the instrument is illustrated by measurements made on a thallium activated potassium chloride phosphor.

ISSN:0034-6748    

DOI:10.1063/1.1745761

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

This paper discusses the theory of a possible method of synchrocyclotron beam deflection in which the orbits expand until the point of maximumHr(n=1) is reached, after which the ions escape and spiral outward. These spirals should have a uniform starting radius and a small pitch in order to give deflection efficiency of the order of 100 percent; it is shown that this requires a flat maximum ofHratn=1, and small amplitude of radial oscillation. The radial and vertical oscillations of the beam and the couplings thereof are discussed in detail. It appears that the only field inhomogeneities which must be carefully minimized are those atn=1 andn=0. Limits on radial and vertical oscillations in the immediate vicinity of the ion source are set but the origins thereof in phenomena other than field inhomogeneity are not discussed.

ISSN:0034-6748    

DOI:10.1063/1.1745762

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745764

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745765

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745766

出版商:AIP    

年代:1951

数据来源: AIP