摘要:

An iterative numerical integration procedure has been developed to correct both beta spectra and differential beta‐gamma directional correlations for the effects of finite instrument energy resolution including the effect of backscattering from a scintillation detector.The method has been tested and found to reproduce the true spectral shape in the cases of Re186, Au198, Tl204, and to allow separation of composite beta spectra as in the case of W187. Application of the method is limited to maximum beta energies exceeding 200 kev.

ISSN:0034-6748    

DOI:10.1063/1.1715680

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The operation of an omegatron is discussed with polyphase electric excitation. Use is then made of this analysis to investigate the ionic trajectories in an omegatron in which the natural frequency of the ion is a function of the orbital radius. This circumstance comes about from either the influence of space charge or from the use of a magnetic field which decreases with increasing radius.The nonuniform magnetic field and the radial electric field can enhance the resolving power. It also influences the peak shape, causing the sides to be nearly vertical.Trapping of the ions is essential for satisfactory operation of the omegatron. Two experimentally proven means of accomplishing trapping are presented.

ISSN:0034-6748    

DOI:10.1063/1.1715681

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The solution calorimeter described previously [Rev. Sci. Instr.26, 477 (1955)] has been modified by using an electrically heated shield for the adiabatic control. In this way the response time has been decreased by a factor of ten which greatly facilitates operation of the control. Under steady conditions the fluctuation in temperature between the calorimeter and its surroundings has been reduced from ±0.002 to ±0.001°C max. The calorimeter has a working range of 10° to 50°C.

ISSN:0034-6748    

DOI:10.1063/1.1715682

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

An apparatus originally conceived for directly preparing capillaries of powders of reactive alloys for x‐ray study inspired the present device. The unit is simply a hermetically sealed chamber which is provided with a drive mechanism at the top, specimen and sight ports at the sides, and a funnel at the bottom. The drive mechanism is used to rapidly rotate a rotary cutter. Particles of any desired size are produced by a suitable choice of cutter and screen. The unit is extremely effective in its original role but has been used to prepare small quantities of powders of reactive alloys for other purposes, and is a versatile research tool.

ISSN:0034-6748    

DOI:10.1063/1.1715683

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A means for measuring the density or the volume of the whole body is essential to reliable estimates of fat in humans. Although Archimedes' principle has often been employed to determine density directly, a method that is less demanding on the subject has been developed for measuring body volume. The apparatus is a closed‐circuit system consisting of two chambers and utilizing a gas‐dilution principle. With the subject in one chamber and helium in the other, the gases in the system are mixed. The helium concentration, measured by thermal conductivity, is related to the tissue volume displacement of the subject. The standard deviation in volume determination is estimated as ±0.12 liter.

ISSN:0034-6748    

DOI:10.1063/1.1715684

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

An atomic clock utilizing the Stark effect has been designed and constructed. In this clock, the error caused by the reflections in the microwave circuits has been successfully reduced to within the error by random noises, and the authors are sure of its possibility of long time operation. The accuracy has been estimated to be about 5×10−9from observation of the received frequency of the standard station JJY, and comparison with the frequency of a quartz chronometer. The various components of this clock are described in detail, and the theoretical limits of the accuracy are also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1715685

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The power sensitivity and the line voltage variation effects of a phase‐shifting thermoregulator making use of a thermal element in a Wheatstone bridge and a grid‐controlled thyratron are expressed in terms of the circuit parameters. The conditions for line voltage variation compensation are derived and the calculated results are found to be in good agreement with the experimental value.

ISSN:0034-6748    

DOI:10.1063/1.1715686

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

For direct measurements of electron intensities in the image plane of the RCA electron microscope a scanning electrometer device has been designed. It consists of a probe and preamplifier, a mechanical drive, an amplifier, and a recording unit. A linear resolution of 0.06 to 0.92 &mgr; is achieved. Sensitivity range is 10−12−10−11amp.

ISSN:0034-6748    

DOI:10.1063/1.1715687

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

An electromechanical device is described for computing the two‐dimensional structure factor formulas,r=1Nfrsincos2&pgr;hursincos2&pgr;kvr  and  r=1Nfrsincos2&pgr;(hur+kvr).fr, ur, vrare fractional and may be fed in to the third decimal place;handkmay vary from −20 to +20. Each term in the series is computed individually to an accuracy of approximately ½&percent; and is automatically added to the existing sum whilst the next term is being computed. The speed of computation is generally equal to the speed with which the variables of each term are fed into the computer. The machine makes use of ``magslip'' resolvers for computation of the trigonometrical functions.

ISSN:0034-6748    

DOI:10.1063/1.1715688

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

An improved four‐window demountable rotating anode x‐ray tube fitted with rapidly interchangeable targets has been constructed. Compactness equal to that of a standard sealed‐off tube has been achieved by the use of an improved re‐entrant vacuum seal and bearing assembly. By employing peripherally directed water cooling in the anode behind the focal spot and a full wave rectified high tension supply, it has been possible to obtain greatly improved performance. With a copper target five inches in diameter rotating at 1000 rpm and with a focal spot 8×0.5 mm, the continuous load at 50 kv was 120 ma without any signs of target erosion.

ISSN:0034-6748    

DOI:10.1063/1.1715689

出版商:AIP    

年代:1956

数据来源: AIP