摘要:

Observations on the normal storage of liquid hydrogen showed the evaporation rate andortho‐paraconversion rate to be consistent with those expected from a noncatalyzed reaction. A catalytic converter which gives 50 percentorthowhen cooled with liquid air was installed in the feed‐gas line of a 25 1/hour hydrogen liquefaction plant. The decrease in storage loss is well worth the trouble of installation and operation of the converter.

ISSN:0034-6748    

DOI:10.1063/1.1770507

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

This paper describes apparatus for measuring internal friction of nonferromagnetic reeds set in transverse vibration. It includes a description of a symmetrical transducer for inducing the vibrations and an optical method of observing the amplitude. Measurements can be made while the reed is temperature controlled and vibrating in a vacuum.

ISSN:0034-6748    

DOI:10.1063/1.1770517

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

A goniometer has been designed to rapidly scan polycrystalline metal samples along a spiral path in a stereographic projection, and which, when used with any recording counting‐rate meter available on a modern x‐ray spectrometer, enables the rapid determination of the preferred crystal orientations of the sample.

ISSN:0034-6748    

DOI:10.1063/1.1770508

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

A scintillation spectrometer making use of a large NaI/TlI crystal mounted on an RCA 5819 photomultiplier tube has been constructed. It was designed for the high efficiency counting of gamma‐rays in the energy range 0.5–1.5 Mev. Techniques used for crystal mounting and assembly of apparatus have proved very satisfactory for prolonged operation. Additional components have been provided for automatic recording of data.

ISSN:0034-6748    

DOI:10.1063/1.1770509

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

Details are given of the design and performance of a heat interchanger suitable for transfering heat from a gas of high heat content per unit volume to one of low heat content per unit volume. The interchanger is suitable for use in large liquefiers, and a report is given of its performance in a helium liquefier giving 6.5 liters of liquid helium per hour. The construction is simple and involves no techniques not already available in an average laboratory workshop. A close correlation is reported between the computed and observed efficiencies and pressure drops in these interchangers.

ISSN:0034-6748    

DOI:10.1063/1.1770510

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

Curves are given for the angular distribution of light scattered from drops of radius 1.4×10−3cm and 4.8×10−4cm for angles from 28° to 147°. The distribution is more nearly symmetrical than had been speculated and depends strongly on the drop size. The intensity of the scattered light was measured with a phototube circuit and galvanometer. The drops were produced in a downward diffusion chamber.

ISSN:0034-6748    

DOI:10.1063/1.1770511

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

A photoelectric method of measuring magneto‐optic rotations as small as 1″ is described. This employs an optical system whereby light from a tungsten lamp traverses two double‐image prisms and is focused by a series of concave mirrors on two 929 phototubes, after passing through a rotating polaroid chopper. The apparatus is now being used in an investigation of the Faraday effect in gases and vapors.

ISSN:0034-6748    

DOI:10.1063/1.1770512

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

An instrument is described which measures continuously and records the index of refraction of flowing liquid streams. The instrument is similar to a spectrograph employing a hollow prism through which the sample stream flows. Refractive index is inferred by measuring the position of the refracted beam of monochromatic light projected to form a slit image. Provision is made to compensate the instrument for rapid changes in temperature of the flowing stream of about ±10° Centigrade on either side of a reference temperature.

ISSN:0034-6748    

DOI:10.1063/1.1770513

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

A design is herein given for an electromagnetic device that can be employed instead of weights or springs for weighing purposes. In this particular design the balancing current is linear with the force applied to the arm of the balance so that current measurement gives a direct reading of weight. A capacity null‐point indicator is also described and so also are electrical circuits that enable this null‐point indicator to automatically operate the electromagnet. These auxiliaries are shown incorporated in a density balance. This balance was sensitive to a change of weight of better than 0.0000001 gram or in terms of oxygen pressure at room temperature to 0.02 mm of Hg. The designs of density balances are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1770514

出版商:AIP    

年代:1953

数据来源: AIP

摘要:

The excitation and evolution of the radial oscillations of ions in the cyclotron has been studied theoretically and experimentally. A simple method for calculating the pattern of the oscillations leads to detailed criteria for the preparation of the magnetic field and a systematic theory of shimming. A new method for measuring the pattern of the oscillations is used to check the theory. The results are applied briefly to the problem of beam extraction.

ISSN:0034-6748    

DOI:10.1063/1.1770515

出版商:AIP    

年代:1953

数据来源: AIP