摘要:

A reliable coincidence circuit of medium resolution with resolving time adjustable between 0.4 and 0.01 microsecond is described. The circuit uses a biased‐diode pulse level selector in either channel, followed by a triggered blocking oscillator. Narrow and constant shape pulses so produced in the channels actuate a coincidence tube, output from which keys a rectangular pulse generator for turning on a power tube connected to a mechanical impulse recorder. Preliminary applications to the study of time fluctuations and delays in proportional counters and to proton time of flight measurements are described.

ISSN:0034-6748    

DOI:10.1063/1.1741063

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

The frequency characteristics analyzer is a device for analyzing the frequency characteristics of filters, amplifiers, and other electronic elements whose pass bands are within the 500–50,000 cycle range.While many frequency analyzers have been constructed, this is one of the first such analyzers in which (1) the width of the swept band and the rate of sweep can be varied independently, (2) the frequency is swept linearly, (3) the response of the pass band circuit can be positioned to appear at any point in the sweep, and (4) the oscillograph time base can be interlocked with the generator frequency.

ISSN:0034-6748    

DOI:10.1063/1.1741064

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

The design and construction of a bridge for the determination of the conductance of electrolytic solutions is described. The best recommendations of other workers are incorporated into the apparatus, and a number of new features and improvements are included. An important characteristic of the bridge is the fact that it may be constructed from easily obtained parts. The instrument has considerable accuracy over a wide range of resistance and may be adapted to the measurement of capacitance.

ISSN:0034-6748    

DOI:10.1063/1.1741065

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

An electrostatic deflection scheme for removing the electron beam from a betatron or synchrotron is considered. The deflection is accomplished in two stages: The first stage is an orbit expansion achieved by a sudden decrease of the magnetic field in the orbit region. The electrons move outwards in spirals of increasing pitch; if the orbit radius is 1 meter and the rate of decrease of the magnetic field is one percent per microsecond, the pitch of the spiral is 1.26 cm at the ``neutral position'' whereHrhas its maximum value. The pitch is proportional to the ⅗ power of the rate of decrease of the field.At the neutral position the beam enters a radial electric field which deflects it outward more sharply. If this field, and the magnetic field with it, extends a distance of about a tenth of the orbit radius beyond the orbit, the electrons will be collimated into a beam whose angular divergence is approximately proportional to (H/E)¾, whereHis the magnetic field at the orbit andEthe electric deflecting field. WithH= 10 kilogauss andE= 60 kv/cm, the angular divergence will be of the order of ten degrees. Curves showing the dependence of the angular divergence onE/Hand on the distance to which the fields extend are presented.

ISSN:0034-6748    

DOI:10.1063/1.1741066

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A counter which combines large solid angle, low operating voltage, ease of changing source, and ability to detect particles of very low energy is described.By means of a revolving plate a sample may be rotated to a position inside the counting chamber through which helium is slowly passing. A large solid angle with low operating voltage is achieved by placing side by side several semicylindrical cathodes whose central wires are electrically connected.Fe55, which has a half‐life of four years, was used as a sample with which to examine the operational characteristics of the counter.

ISSN:0034-6748    

DOI:10.1063/1.1741067

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A description is given of a transducer which utilizes, for the transformation of sonic to electrical energy, the electrokinetic potential developed by the movement of a fluid through a porous solid. The construction and calibration of the transducer are discussed, and results of measurements of the pressure fluctuations in oil pipe lines are presented.

ISSN:0034-6748    

DOI:10.1063/1.1741068

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

An apparatus is described by means of which plots of the equipotentials of two‐dimensional fields may be made automatically from models of the electrodes. The usual electrolytic tank method has been extended by the addition of a servomechanism which causes the probe to traverse an equipotential automatically. A stepping relay operated by a limit switch effects automatic plotting of successive equipotentials and limits the plot to a desired area. A number of plots made with such an apparatus are reproduced.

ISSN:0034-6748    

DOI:10.1063/1.1741069

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

An instrument has been designed to measure low amplitude waves whose frequencies fall between those of the wind‐generated ocean swell and those of the astronomic tides. Its maximum sensitivity is to waves whose period is 15 minutes, and its pass band extends approximately from 2‐minute periods to 2 hours. The suppression of the ocean swell and tides (whose amplitudes are much greater than those of the waves to be studied) is accomplished by means of capillaries and air chambers which give the instrument a response characteristic analogous to that of an electricalR—Ccircuit. Records obtained show the continual presence of waves in this previously unexplored portion of the spectrum of gravity waves in the sea.

ISSN:0034-6748    

DOI:10.1063/1.1741070

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A simple electronic temperature controller has been developed which incorporates ``proportional'' control action. Utilizing a resistance thermometer element, its precision of operation is determined ultimately by the stability of the resistance element and the gain of the amplifier. Its operation is essentially independent of line voltage.

ISSN:0034-6748    

DOI:10.1063/1.1741071

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A procedure for making Be foils between 10−5‐cm and 10−3‐cm thick, and with diameters up to an inch and a half, is described, and methods of mounting these foils are indicated.

ISSN:0034-6748    

DOI:10.1063/1.1741072

出版商:AIP    

年代:1948

数据来源: AIP