摘要:

A description is given of a large Dempster‐type double‐focusing mass spectrograph. The dispersion of the instrument is 2.3 mm for one percent mass difference. The theoretical resolution for a 0.001‐in. principal slit is 7000 and has been experimentally realized. The performance of the instrument is illustrated by a mass spectrum showing doublets formed by singly‐charged Cu and Zn and triply‐charged Pt.

ISSN:0034-6748    

DOI:10.1063/1.1745422

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

A diaphragm cell for thermal diffusion using a fritted glass disk like those used for ordinary diffusion is described. The results obtained are consistent with those obtained for other cells, and the operation of this cell is simpler and shorter than for most other methods.

ISSN:0034-6748    

DOI:10.1063/1.1745423

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The glow discharge in air at atmospheric pressure from a point of fine platinum wire has been experimentally investigated in its sensitivity to variations of pressure, velocity, temperature, and humidity, as well as such variables of the instrument as needle point characteristics, location and shape of the other electrode, and magnitude of the discharge current. It has been concluded that the glow current is markedly pressure sensitive, has low velocity sensitivity, is only slightly humidity sensitive, and is negligibly sensitive to ordinary temperature variations. The device offers a significant improvement over conventional pressure measuring instruments by the small size of its sensitive portion (of the order of 0.001‐inch diameter wire and 0.002‐inch glow diameter) and in its response to high frequency variations (more than 106c.p.s. has been demonstrated experimentally). It suffers from high background noise in the present arrangement. A workable instrument is not presently described, but rather, some promising possibilities are shown to exist. The successful application to measurement of instantaneous pressures in very high frequency sound has been made, however; and the instrument will be reported as soon as possible.

ISSN:0034-6748    

DOI:10.1063/1.1745424

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

Means are described for measuring magnetostatic fields from the order of one milligauss to 100 gauss. The operation consists of measuring the second harmonic content of the exciting current for a ferromagnetic strip which is normally excited to partial saturation. The second harmonic component appears when the strip is biased by an external magnetic field and the amount is directly proportional to this field over the bulk of the useful range. Methods of use are described.

ISSN:0034-6748    

DOI:10.1063/1.1745425

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

Described is an instrument for observing or photographing fast voltage transients. It consists of a sweep generator with sweep speeds ranging from 30 cm per microsecond to 0.05 cm per microsecond, a vertical deflection amplifier having a rise time of 0.005 microseconds and a preamplifier which, when used with the deflection amplifier, produces an over‐all rise time of 0.0063 microseconds with a gain of about 1,000. These units are used in conjunction with a type 5XP cathode‐ray tube using 20 kilovolts accelerating voltage.

ISSN:0034-6748    

DOI:10.1063/1.1745426

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

The design and construction of a new type of function generating potentiometer, whose output voltage may be made proportional to a wide variety of functions of the shaft rotation, is described. Voltages corresponding to the desired function values are set up at will at the taps of a linear potentiometer, which then interpolates linearly between these values. The new device combines remarkable flexibility with relatively low cost.

ISSN:0034-6748    

DOI:10.1063/1.1745427

出版商:AIP    

年代:1950

数据来源: AIP

摘要:

Experiments with argon‐ethyl acetate mixture in small counters are described. Details of construction are given for two designs of brain probing counters of 3‐ and 2‐mm diameters.

ISSN:0034-6748    

DOI:10.1063/1.1745429

出版商:AIP    

年代:1950

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745431

出版商:AIP    

年代:1950

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745432

出版商:AIP    

年代:1950

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745433

出版商:AIP    

年代:1950

数据来源: AIP