摘要:

A new method for the assay of tritium is described. Radioactive water is reacted with methyl Grignard reagent to give radioactive methane which is then admitted into a proportional counting chamber to be counted. Advantages of the method are convenience, absence of memory effects, linearity, and a precision with a standard deviation less than 1 percent.

ISSN:0034-6748    

DOI:10.1063/1.1745936

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A low current integrator is described that successfully avoids the problem of current leakage by the use of electrometer tubes. In connection with the circuit an electronic master switch is described which permits the turning on and off of associated equipment with the beginning of the charging cycle of the integrator.

ISSN:0034-6748    

DOI:10.1063/1.1745937

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A device giving a time delay up to 10‐sec duration and having a precision of 1 millisec is described. A simplified form of the device can be employed as a trigger‐operated stop clock for timing periods of any length.

ISSN:0034-6748    

DOI:10.1063/1.1745938

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Using the simplest optical parts a monochromator with a nominal band width of about 15A was constructed, covering the range of 3600 to 9000A. This monochromator, in combination with suitable photocells and a direct reading, linear, negative feedback amplifier, permits the determination of extinctions with an error of about 1.5 percent.The performance of the instrument was checked by measuring the absorption spectra of rare earth ions.

ISSN:0034-6748    

DOI:10.1063/1.1745939

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An electrostatic transformer of direct current which permits the continuous transfer of electrical charges from a primary circuit to a secondary circuit by means of a rotating dielectric is described. The primary circuit consists of a pair of metallic brushes connected to a source of high voltage, the moving dielectric being placed between them. A similar pair of brushes, placed at a convenient distance away, constitutes the secondary terminals. The continuous transfer of charges permits the passage of a steady current from the secondary brushes. In the one‐to‐one ratio electrostatic transformer the secondary voltage is slightly less than the primary voltage owing to losses, but since the primary circuit and secondary circuits are separated by insulating material, it is possible to place several disks on a shaft and to connect the primary brushes in parallel and the secondary brushes in series, obtaining in this way a step‐up transformer. The elementary theory is developed and experimental results are shown.

ISSN:0034-6748    

DOI:10.1063/1.1745940

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A manometer has been developed for the pressure measurement of very pure gases or condensable vapors. It can be outgassed at high temperatures, is rugged in construction, and has a maximum error of 10−2mm Hg.

ISSN:0034-6748    

DOI:10.1063/1.1745941

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Of the several circuits for timing control of small spot welders which have recently appeared in the literature, the one which seems to the author to be most practical does not include circuit parameters or components. A certain amount of effort is required, therefore, in selecting parameters and components. It is the purpose of this article to provide this information.

ISSN:0034-6748    

DOI:10.1063/1.1745942

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Many instruments exist which will magnify small displacements to almost any degree desired but always at the expense of range. The micrometer screw is a notable exception, but does not given an electrical output nor will it measure distance directly and continuously without extra equipment. The present device combines a lever, a micrometer screw, a sensing element, and a servomotor to achieve this purpose.

ISSN:0034-6748    

DOI:10.1063/1.1745943

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An automatically computing and recording instrument for dielectric constant and dielectric loss as a function of temperature at any constant frequency from 50 cps to 600,000 cps is described. Sample curves are shown. Known magnification and zero shift are incorporated to cover the ranges of values encountered in most plastic materials. Automatic correction for and measurement of thermal expansion is incorporated.

ISSN:0034-6748    

DOI:10.1063/1.1745944

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

The Yale linear accelerator has been designed to produce large currents of 10‐Mev electrons by the use of independent resonant cavities driven by 500‐kw triode power amplifiers. The design principles and construction methods used for this recently completed machine and data on its performance are presented.

ISSN:0034-6748    

DOI:10.1063/1.1745945

出版商:AIP    

年代:1951

数据来源: AIP