摘要:

Instrumentation to automatically record amplitude distribution curves is described. Basically the method employed is that proposed by Landon in which one measures the relative lengths of time that a signal is equal to, or less than, a given amplitude. A digital approach, similar to that of Davenport, is made. However, instead of modulating a pulse train with the studied signal, as done by Davenport, the described analyzer mixes the amplitude of a high frequency sinusoid with the studied signal, producing greater stability and requiring less bandwidth. The amplitude is scanned by reducing the amplitude of the carrier sinusoid, while keeping the rms value of the studied signal constant. The distribution curves of a random noise sample and of two sinusoids, the latter of which are used in calibration of the amplitude axis, are presented.

ISSN:0034-6748    

DOI:10.1063/1.1717466

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

A system of two pulsed iron‐free magnets, designed for an experiment in high energy physics is described. One of these is a small solenoid, with a working volume of about 35 cm3, pulsed at 200 kgauss; the other is a large magnet with a volume of about 6 liters, pulsed at a nominal 15 kgauss. Construction details, working lifetimes, and details of switch gear are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1717467

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

The angular resolution and azimuthal symmetry of an unshielded NaI scintillation counter was measured for gamma rays between 0.5 and 2.8 Mev in order to estimate correction factors needed in determining angular correlation functions. The results are in agreement with the corrections calculated by Rose, and extended by Stanford and Rivers, for similar scintillation crystal geometry.

ISSN:0034-6748    

DOI:10.1063/1.1717468

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

Several carbon thermometers have been prepared with various sizes of carbon particles and new rugged construction methods. The resistance of the thermometers has been measured as a function of temperature from 1.217° to 20.355°K and as a function of magnetic field from 0 to 94 500 gauss. No simple functional relationship holds between resistance and temperature or between resistance and magnetic field. An approximately square dependence of the resistance on the magnetic field holds for some thermometers at small fields, but in no case does this dependence continue at high fields.

ISSN:0034-6748    

DOI:10.1063/1.1717469

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

Efficient electrodeless discharge spectral lamps have been developed that are suitable for transmission monitoring of optically polarized quantum systems. The lamps have a surface brightness close to the theoretical limit with substantially no self‐reversal. The limiting intensity fluctuations observed appear to be that of photon shot noise. Predicted life of the lamp is in excess of 5000 hr.

ISSN:0034-6748    

DOI:10.1063/1.1717470

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

This paper describes a seven‐pound device that indicates changes in the refractive index of a gas. Because it is capable of detecting refractivity fluctuations that are as small as one part per million, it is useful in studying the irregularities in the refractive index of the troposphere that are important in short radio‐wave transmission. The refractometer is self‐contained, so that it may be used in controlled or in free ascent through the atmosphere. The device is essentially a high frequency oscillator whose frequency is governed by the capacitance of an air sensing condenser. Special provision is made for reliable operation over the wide range of temperatures normally found in the troposphere.

ISSN:0034-6748    

DOI:10.1063/1.1717471

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

A directional Cˇerenkov counter has been developed for detection of energetic gamma rays from balloons and satellites. It is sensitive to photons whose directions lie within a 10° cone. It is completely insensitive to backward fluxes and almost completely insensitive to charged particles. Several different versions of the system have been constructed, and tested in bremsstrahlung beams. The angular resolution has also been indirectly confirmed by using the device to count cosmic ray muons at sea level.

ISSN:0034-6748    

DOI:10.1063/1.1717472

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

The study of the reaction kinetics of high boiling liquids in the gas phase has been limited because of the problems involved in introducing the reactant and the difficulty of monitoring pressure changes. Difficulties have arisen with these reactants because of their decomposition during their distillation into the reactor. Pressure monitoring has been hampered due to condensation of the reactant and/or products in an apparatus possessing a cold zone (such as a capillary leading to a pressure measuring device) outside the thermostat. A new reactor has been built for conveniently studying reaction kinetics of high boiling liquids in the gas phase which provides a means of rapid, easy introduction of the reactant and careful monitoring of pressure changes. Reaction rates were determined for the pyrolysis of 1,2‐diarylethyl acetates.

ISSN:0034-6748    

DOI:10.1063/1.1717473

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

The long‐time stability of an inhomogeneous magnetic field is measured with a precision of 3×10−5. The system is instrumented for short‐time dependence on component stability while referencing on a precision homogeneous field with NMR. An InAs Hall effect sensor is positioned in the gap of a permanent magnet assembly. The Hall voltage is balanced by a low voltage reference source. Without changing the reference voltage the Hall probe is placed in the field of a 6‐in. electromagnet whose field is varied to again obtain null, then is measured with an NMR gaussmeter. The time requirement on component stability is about one minute. The Hall probe is temperature controlled to ±0.01°F.

ISSN:0034-6748    

DOI:10.1063/1.1717474

出版商:AIP    

年代:1961

数据来源: AIP

摘要:

An electromagnetic servo‐balance designed for use in susceptibility measurements is described. A differential transformer is used as the sensing element, and the position of the beam is indicated visually by a meter with a zero‐centered scale. A switching arrangement allows the servo circuit to be disconnected from the balance and a circuit for manual control of the balancing current substituted.

ISSN:0034-6748    

DOI:10.1063/1.1717475

出版商:AIP    

年代:1961

数据来源: AIP