ISSN:0034-6748    

DOI:10.1063/1.1749081

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749082

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749084

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

An x‐ray tube which operates successfully up to 650,000 volts has been constructed from a conical porcelain transformer bushing, rated at 750,000 volts external flashover. Although the bushing had previously been filled with transformer oil, no difficulties were encountered in outgassing the inner surface. With a pumping system of about 300 liters per second capacity, a vacuum of 10−5mm can be maintained, and this does not change appreciably during operation. Cold emission from the anode, rather than gas current or breakdown of the porcelain, limits the voltage which can be applied. Filament emission currents up to 4 milliamperes can be employed without undue heating of the target. For a given voltage, a porcelain tube of this type is much more compact than a glass tube, the strength of its walls against puncture makes elaborate internal shielding unnecessary, and there is no more difficulty in maintaining a good vacuum than in a glass tube of comparable volume. The source of high potential is the 1,000,000 volt transformer set in the High Tension Laboratory.

ISSN:0034-6748    

DOI:10.1063/1.1749085

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749086

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

A grazing‐incidence vacuum spectrograph for a twenty‐one foot focal‐length grating has been set up and adjusted. The angle of incidence is 79 degrees. The various adjustments on the instrument which enabled rapid focussing are described. Very sharp lines have been obtained, and some spectrograms of copper are compared with others which were taken by a one‐meter grazing‐incidence vacuum spectrograph. These definitely show the advantage of the large dispersion of the new instrument. Several groups of lines have been found which appear to be multiplets but as yet have not been classified. Work is being continued on Be, B, Al, Cu, Ni, Co and Zn.

ISSN:0034-6748    

DOI:10.1063/1.1749087

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

A sensitive and accurate method is described for measuring electromotive force through large resistances, up to around 100,000 megohms, or for measuring electromotive force in systems which are easily polarized. The measuring instrument is simply and inexpensively constructed of standard parts which are readily available, and in actual use it is convenient, dependable and rugged.

ISSN:0034-6748    

DOI:10.1063/1.1749088

出版商:AIP    

年代:1933

数据来源: AIP

摘要:

The present paper presents a study of this hydrometer and makes several suggestions: (1) Care must be exercised in the choice of ferrous material for the core and of the weight of that core. Permalloy is recommended. (2) Unless permalloy is used, a mixture of d.c. and a.c. is recommended for producing the magnetic pulls, only the d.c. being measured. (3) The equations are used to give hints for calibration and design.

ISSN:0034-6748    

DOI:10.1063/1.1749089

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749090

出版商:AIP    

年代:1933

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1749091

出版商:AIP    

年代:1933

数据来源: AIP