ISSN:0034-6748    

DOI:10.1063/1.1752042

出版商:AIP    

年代:1936

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752043

出版商:AIP    

年代:1936

数据来源: AIP

摘要:

Experiments were conducted to develop a more economical and satisfactory target for a 650,000‐volt x‐ray machine. It was found that lead, electroplated onto a thin, stretched disk of copper cooled with water would withstand up to 2 ma/sq. cm electron bombardment continuously at 650 kv. This technique seems applicable for experimental tubes where lead or other low melting metal is desired for a target material.

ISSN:0034-6748    

DOI:10.1063/1.1752044

出版商:AIP    

年代:1936

数据来源: AIP

摘要:

When hydrochloric acid vapor and water vapor are allowed to diffuse together the mixture obtained is supersaturated with respect to both components. An ionizing particle passing through the mixture causes a string of droplets to form by condensation of the supersaturated vapors on the ions. Utilizing this chemical method of producing supersaturated vapors a very simple type of continuously active cloud chamber without moving parts has been developed. The cloud chamber in its present stage of development is not suitable for photographic recording but is useful for demonstration purposes. Cosmic‐ray tracks can be seen with ease by visual observation.

ISSN:0034-6748    

DOI:10.1063/1.1752045

出版商:AIP    

年代:1936

数据来源: AIP

摘要:

The starting potential of Geiger‐Mu¨ller counters filled with various pressures of air, helium, hydrogen, oxygen, argon, and two argon‐oxygen mixtures have been accurately determined for counters with oxidized copper cylinders 1.0 cm in diameter, and bare tungsten wires 0.0075 cm, 0.0125 cm, and 0.025 cm, diameter. Except at low pressures, Werner's equation fits the results fairly well, when suitable constants are chosen, for all these gases except helium. At low pressures, the starting potentialsdiminishas the size of the wire increases.

ISSN:0034-6748    

DOI:10.1063/1.1752046

出版商:AIP    

年代:1936

数据来源: AIP

摘要:

Detection of small a.c. voltages over a wide range of frequencies with sensitivity comparable with d.c. necessitates methods, equipment, and technique far in advance of that required for the equivalent d.c. measurements. The portable d.c. meter offers the ultimate in simplicity, compactness, and ruggedness for use as a d.c. null indicator. A simple method of detecting a.c. voltages is by use of a d.c. meter in conjunction with a rectifier. Perhaps the metallic thin film rectifier is the best to date for above use from the standpoint of simplicity, ruggedness and compactness. The d.c. meter and rectifier as conventionally used are unreliable for null indications because of inherent characteristics of the rectifier.

ISSN:0034-6748    

DOI:10.1063/1.1752047

出版商:AIP    

年代:1936

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752048

出版商:AIP    

年代:1936

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752049

出版商:AIP    

年代:1936

数据来源: AIP

摘要:

A modified Wynn‐Williams scale of eight counting circuit is described which employs type 885 argon filled tubes. These tubes have the advantages of a very small deionization time, characteristics independent of temperature, and low cost.

ISSN:0034-6748    

DOI:10.1063/1.1752050

出版商:AIP    

年代:1936

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1752051

出版商:AIP    

年代:1936

数据来源: AIP