摘要:

For a sector‐shaped, uniform magnetic field with source and detector outside the field, the non‐uniform fringing fields can be employed to give simultaneous focusing of charged particles in two perpendicular directions. Equations for determining the position of the doubly‐focused image are developed and graphs are given for some representative arrangements. This double focusing can be combined with the methods recently developed for second‐order focusing, to increase further the useful solid angle of a uniform‐field mass or momentum analyzer. Fringing‐field focusing can also be used in concentrating to a point a parallel beam of finite cross section.

ISSN:0034-6748    

DOI:10.1063/1.1745747

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

Focusing properties of the inverse‐radial potential in the spherical electrostatic analyzer for charged particles having relativistic speeds are calculated by a first‐order method valid for large values of &bgr;=v/c.Extending similar calculations of focusing by the logarithmic potential in the cylindrical analyzer, the treatment stresses deviations from focusing properties for low speed particles, and emphasizes analogies between the characteristics of focusing accomplished by each type of field, wherever possible. Approximate formulas are given by which the diameter of the region of least confusion may be computed for several interesting situations.

ISSN:0034-6748    

DOI:10.1063/1.1745748

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A means for adding, without circuit modification or wiring changes, continuously tunable band‐pass or band‐reject selectivity to existing audio amplifiers is described. This takes the form of an external electronic circuit connected to the amplifier by means of a wire attached to the plate pin of one tube, and a common ac ground connection.The arrangement is useful in laboratory and experimental work for temporarily rejecting or amplifying a particular frequency.

ISSN:0034-6748    

DOI:10.1063/1.1745749

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An attempt is made to understand quantitatively the effects of a given gas, gas pressure, vapor, ionization density, and temperature distribution on the operation of diffusion chambers. An integral equation is set up which takes into account diffusion of the vapor through the gas, removal of vapor by condensation, drop growth, and the motion of the drops due to gravity. Temperature distributions necessary to produce tracks through a given depth of a chamber are calculated, applying to a wide variety of different conditions. For example, the average temperature gradient for operation with methanol and air at 1 atmos or hydrogen at 10 atmos exposed to sea level cosmic radiation amounts to 3.6°C/cm while for air at 3 atmos or hydrogen at 30 atmos a gradient of 6.3°C/cm would be required. Because of the formation of uncharged drops at higher operating temperatures and because of the onset of semi‐stable convection currents in the light gases operation is expected to become difficult with air at a pressure >3 atmos or hydrogen at a pressure >30 atmos, or with ionization densities >4 times sea level cosmic radiation at 1 atmos of air.

ISSN:0034-6748    

DOI:10.1063/1.1745750

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A circuit is described for controlling the output current of a high current (100 amp) dc generator driving a low impedance (2.5 ohm, 40 mh) load. The circuit features precise continuous control of the load current by a single dial potentiometer over the range from zero to full output, with 0.03 percent linearity of currentvspotentiometer setting. A method is presented for reduction of current ripple from the generator in the low impedance load.

ISSN:0034-6748    

DOI:10.1063/1.1745751

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An instrument is described which measures a time interval and them immediately generates an interval of time equal to the measured interval, for automatically timing a light source flash for photographing missiles whose velocity cannot be predicted.

ISSN:0034-6748    

DOI:10.1063/1.1745752

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

The device described in this paper reflects a general philosophy for the fuller utilization of analog computing devices which has been promoted at Watertown Arsenal Laboratory. When solutions of analog computers are used as tools in conjunction with techniques readily handled by standard desk calculators rather than as direct solutions, any desired accuracy of the final solution can be usually obtained. The emphasis is placed upon obtaining the equivalent of a large scale digital device by combining solutions from analog computers with techniques readily handled by very small digital devices.

ISSN:0034-6748    

DOI:10.1063/1.1745753

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

An alpha‐particle spectrometer, using a 60° sector magnet capable of focusing alpha‐particles of energies up to 14 Mev, is described. Description of the instrument, sample technique, focusing properties, and current supplies are discussed. Transmission is about 0.01 percent of the total solid angle of the sample and with a resolution of 8 kev.

ISSN:0034-6748    

DOI:10.1063/1.1745754

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

A light weight, low current drain system for the geomagnetic orientation of experimental equipment during a high altitude balloon flight is here described. The system is specifically designed to keep nuclear emulsions oriented to within ±5 degrees of a chosen geomagnetic heading. The error detector consists of a high impedance ac bridge, two of whose arms are electrolytic resistance paths in ethyl alcohol. Deviation of a compass needle, immersed in the electrolyte, from a chosen ``on‐course'' line unbalances the bridge. A correcting motor is started when the off course deviation unbalances the bridge to a sufficient predetermined extent. Direction of motor rotation is determined by the sense of the error. Quiescent power drain is 1.4 watts. Motor operation increases this drain by 4 watts. Flight analysis of orientation is made possible by an integrating camera. Some control characteristics are given.

ISSN:0034-6748    

DOI:10.1063/1.1745755

出版商:AIP    

年代:1951

数据来源: AIP

摘要:

The construction, calibration, and use of a dilatometer that is ideally suited for use with radioactive materials is described. Expansion measurements are made electrically with a linear variable transformer.

ISSN:0034-6748    

DOI:10.1063/1.1745756

出版商:AIP    

年代:1951

数据来源: AIP