ISSN:0034-6748    

DOI:10.1063/1.1751517

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751518

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

A portable power supply capable of furnishing up to 2500 volts at ten microamperes is described. An input of 45 volts at 3 milliamperes gives 600 volts output with a constancy equal that of the driving battery. The weight including the 600‐volt output condenser but excluding batteries is 450 grams. A modification requiring a 90‐volt supply and weighing 175 grams is discussed. Possible additional uses such as pulse generator, counting‐rate‐meter and ignitron control are mentioned.

ISSN:0034-6748    

DOI:10.1063/1.1751519

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

An oversize tube of transparent plastic is put into a slotted steel supporting tube by cooling in liquid air. Such a device using Bakelite BT 43 001 has proven reliable at 400 atmospheres, and calculations indicate 1000 atmospheres as the upper limit of safety for tubes of this general type and material. The most important feature is the absolute reliability. This is due to the fact that in operation no primary tensile stresses exist in the transparent material.

ISSN:0034-6748    

DOI:10.1063/1.1751520

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

A two‐stage direct‐coupled amplifier circuit with negative feedback which can be used for measuring small direct currents is described. The circuit details are given for a multi‐range micromicroammeter which is compact and stable and operates from a.c. power. Through reduction of grid current in the input tube, which is a standard receiving type, it is possible to realize a high sensitivity approaching that of amplifiers using special electrometer tubes.

ISSN:0034-6748    

DOI:10.1063/1.1751521

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751522

出版商:AIP    

年代:1939

数据来源: AIP

摘要:

Resolving power, preferred thickness and balance errors of Ross filters for x‐ray monochromatization are discussed. It is theoretically impossible to balance two filters of elementary composition because of scattering,Llimits andKjump, even if the absorption coefficients of the two filters vary similarly with wave‐length between the limits, which is not known to be the case. It suffices, however, to obtain good balance for wave‐lengths near the pass band since others longer and shorter may be relatively reduced by pre‐filtration through a filter whose composition is the same as that of the high atomic number member of the balanced pair. TheKjump balance error may be completely removed by adding a slightly absorbing filter of low atomic number to one member of the pair. By employing a specially designed ionization chamber Ross filters may be used simultaneously instead of alternately and a considerable gain in speed and accuracy achieved.

ISSN:0034-6748    

DOI:10.1063/1.1751523

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751524

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751525

出版商:AIP    

年代:1939

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1751526

出版商:AIP    

年代:1939

数据来源: AIP