ISSN:0034-6748    

DOI:10.1063/1.1745733

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Using a &bgr;‐ray lens spectrometer to supply electrons of a given energy, a study of the response of the anthracene scintillation counter to monoenergetic electrons has been made. It has been found that pulse height varies linearly with energy from 125 to 3200 kev but below 125 kev the pulse height varies less rapidly with energy. The differential counting rate distribution for given energy settings of the lens spectrometer were found to follow a Gaussian distribution and that on the average 3.3 kev is required to produce one effective photo‐electron at the cathode. When Morton's correction for dynode losses is applied, it is found to require 2.5 kev for the production of one photo‐electron at the cathode or that 400 electrons enter the multiplier per Mev of incident electron energy. This is in agreement with the 420 electrons per Mev obtained by direct measurement. Assuming a 10 percent photoelectric efficiency at the photo‐sensitive surface, it appears that the efficiency of anthracene for the conversion of incident electron energy into photon energy is of the order of one to two percent.

ISSN:0034-6748    

DOI:10.1063/1.1745734

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

By use of two mixers and a common variable local oscillator, a super‐heterodyne receiver, such as General Radio Wave Analyzer No. 736‐A, can be converted to serve simultaneously as generator and detector. Such an arrangement provides: (1) single dial tuning, (2) absolute freedom from relative frequency drift, (3) the possibility of very narrow band tuning and, thus, improved signal‐to‐noise ratio. Circuits to accomplish this are described for the range 0–16 kc which occupy no more space than a conventional oscillator, which they replace. Extension of the frequency range to 0–600 kc is possible by simple changes and the use of an RAK‐7 commercial receiver, although in this case single dial tuning is not possible. These circuits are particularly useful for automatic balancing dielectric bridges, but should also be very useful in work with vibration and sound, and for filter and amplifier frequency response.

ISSN:0034-6748    

DOI:10.1063/1.1745735

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

The operation of cylindrical proportional and Geiger counters near the ends of the wire is examined closely by means of thin sheets of soft homogeneousX‐radiation. It is found that small field‐adjusting tubes, fitted over the usual grounded guard tubes (where these are required) and maintained at the potential appropriate to their diameter, reduce the end effects to negligible proportions. The computed field distribution is thus confirmed experimentally. Both theory and practice show that the concentric field‐adjusting and guard tubes need not be longer than a radius of the counter. The method can be used in designing counters of very short operating length. In practice the technique is simple and it can be applied to the construction of ionization chambers (pulse or steady current type), proportional counters with constant gas gain along the whole wire, and Geiger counters. It insures in each case a precisely defined counting volume.

ISSN:0034-6748    

DOI:10.1063/1.1745736

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An adaptation of the electromagnetic flowmeter has been made for the observation of transients in liquid flows. The device responds to flow transients of 0.001‐sec duration, and is not affected by ambient pressure changes or the velocity profile of the liquid in the conduit. The effects of fluid resistivity on the instrument are noted.

ISSN:0034-6748    

DOI:10.1063/1.1745737

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745738

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745739

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745740

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745741

出版商:AIP    

年代:1951

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1745742

出版商:AIP    

年代:1951

数据来源: AIP