摘要:

A laboratory tube has been developed which produces scale models of the forms assumed by streams of charged particles in the earth's dipole magnetic field. The forms are unexpectedly intricate and complicated, as are also the contacts on the earth's surface. Photographs of some representative stream forms and contacts are presented. The tube has served as an analog computer for stream forms and contacts and, in addition, has revealed the importance of the generation of ring currents of charged particles scattered into Sto¨rmer's periodic orbits. The same techniques can be applied in studies of stream forms in high‐energy accelerators and in other complicated kinds of magnetic fields.

ISSN:0034-6748    

DOI:10.1063/1.1716491

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The instrumentation used, the measurements obtained, and the uses of the Vanguard I satellite are described. This satellite contains two transmitters, one powered by batteries for about three weeks and one powered by solar cells (still operating). From the transmitted frequencies temperature information and rotation rates are obtained. The transmitted signals are also used to determine the satellite orbit. An approximate free orbital lifetime of 200 years is predicted.

ISSN:0034-6748    

DOI:10.1063/1.1716492

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

Equipment was constructed to demonstrate the practicability of using a Vidicon camera tube for measuring the space orientation of spin stabilized Aerobee‐Hi research rockets. While ordinary television pictures are badly blurred by camera rotation, laboratory photographs which were obtained by means of a spinning, line‐scan camera demonstrated that this method can be used to obtain pictures whose quality is similar to those of standard television.

ISSN:0034-6748    

DOI:10.1063/1.1716493

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

A simple, crystal‐controlled, transistorized marginal oscillator magnetometer has been built. It is self‐contained except for an oscilloscope and modulation power supply. Circuit and construction details are given.

ISSN:0034-6748    

DOI:10.1063/1.1716494

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The modification of the single particle theory of particles subject to radio‐frequency acceleration caused by electrostatic repulsion between particles is calculated. With the aid of an appropriate Hamiltonian the Boltzmann equation is reduced to a one‐dimensional integral equation for the case of a uniform particle density in a limited region of phase space. For a range of parameters that includes most accelerators, this equation is approximated by an algebraic equation, and an analytic solution valid below the transition energy is obtained. Computations are given of the ``longitudinal space charge limit,'' as well as the effect of space charge on the azimuthal bunching of a beam by an accelerating cavity. Numerical examples of these two effects are given.

ISSN:0034-6748    

DOI:10.1063/1.1716495

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

Photoconductivity in certain selected single crystals of CdS, by comparison with conventional Geiger‐type counters, affords a fairly sensitive and inexpensive detector for simple x‐ray spectrometry.

ISSN:0034-6748    

DOI:10.1063/1.1716496

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

A transistorized marginal oscillator type of nuclear resonance probe is described. The main advantages of transistor use are in obtaining portability, eliminating external power sources, and low cost. The sensitivity and stability equaled that of a standard transition vacuum tube circuit when compared using protons in water.

ISSN:0034-6748    

DOI:10.1063/1.1716497

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The roots of polynomials of high degree are obtained with a stated accuracy in a time of ten to thirty minutes by use of an electromechanical harmonic synthesizer. The machine consists of sine‐cosine potentiometers which are driven by meshed gears to produce sinusoidal potentials of frequencyf, 2f, 3f, …. The algebraic polynomial is transformed into a trigonometric polynomial in which the terms are expressed in multiple angle form and applied to the machine. As the fundamental gear is rotated through 180°, the potentials are summed in a recording high impedance voltmeter in such a manner that when the curvef(&thgr;)=0 passes through zero values, the angles are read from a large dial and the rootsx=rcos &thgr; are obtained.Examples of the solutions are given, and the results of some twenty‐five solutions reported to show an average accuracy of 1.19% and an average time of solution of 16 minutes. For higher accuracy a time of about 7 minutes is required for each additional substitution, until an accuracy of 0.30% may be obtained. Multiple or repeated roots are obtained by use of the factor theorem and repeated differentiation.

ISSN:0034-6748    

DOI:10.1063/1.1716498

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

Electrical leads carrying currents into cryogenic apparatus also introduce heat. Even with an ideal Carnot cycle, the mechanical power needed to remove this heat can be one hundred or more times the heat flow itself. If the currents and hence the input leads are heavy, a very sizeable refrigerator may be required. In this article the configuration of the leads which minimizes the influx of heat is derived theoretically, taking variations in thermal and electrical conductivity into account. Graphs are given for the minimum heat flow and optimum cross section of a copper input lead carrying arbitrary currentI. The optimum is found to be fairly sharp. If the diameter of the lead differs by a factor of two from the optimum, the influx of heat is increased by over 100%.

ISSN:0034-6748    

DOI:10.1063/1.1716499

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

A short duration (1 or 2×10−8second) high‐intensity explosive light source, that may be used in the laboratory, has been proved experimentally. The charge, weighing 4.8 grams, yields a luminosity estimated in the neighborhood of 8×107lumens. Pictures of high‐speed shocks in air, transparent solids, and metal jets have been taken using this lighting system.

ISSN:0034-6748    

DOI:10.1063/1.1716472

出版商:AIP    

年代:1959

数据来源: AIP