摘要:

A versatile chronographic technique for the measurement of detonation velocities in liquid and solid explosives is discussed. A raster‐type oscilloscope is described which has a sweep linearity of 1&percent; and a time coverage of 300 &mgr;sec. This instrument is composed of standard electronic components and requires relatively little maintenance. The basic signal mixing circuits used to generate fast‐rising pulses associated with the detonation of an explosive charge are briefly described. Some electrical effects associated with the detonation of an explosive charge are briefly described to point out a possible source of spurious signals. Techniques for the preparation and assembly of explosive charges are presented together with certain precautions which must be taken against the possibility of the generation of false signals. The effect of temperature on detonation velocities of liquid and solid explosives is mentioned. Using the techniques and precautions described, it is possible to obtain detonation velocity data with a precision of 0.1&percent; or better.

ISSN:0034-6748    

DOI:10.1063/1.1715639

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The term ``glo‐ball'' is used to designate a small, thin‐walled, partially evacuated glass sphere containing helium, used for investigating electric field distributions in rf resonant cavities. Ionization, or firing, of the gas in the glo‐ball indicates a given potential gradient across it; in field investigations a monitoring loop is used to record the voltage required in the cavity to produce this ionization. Glo‐balls were developed specifically for their application to linear accelerators.Experiments were conducted to provide a method of making glo‐balls, under controlled conditions with known constituents, that would have a stable and relatively low firing gradient.Factors associated with the making of a glo‐ball were determined, and a spectroscopic analysis identified the gas components. It is now possible to make a ball that fires at a minimum voltage gradient with excellent stability. Other characteristics of the glo‐ball pertinent to its use as a field‐measuring device were investigated.

ISSN:0034-6748    

DOI:10.1063/1.1715640

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A simple mechanical calculator has been developed for solving the transmission line equations when the characteristic impedance is a variable. The speed of computation is some two orders of magnitude faster than analytical methods. The theoretical basis is described and also the way in which it can be used. Some representative problems, which have benefited by use of the calculator, are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1715641

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The naturally peaked x‐ray beam from the 70‐Mev synchrotron has been collimated and compensated to flatness by differential absorption in a copper filter. Angulation of the synchrotron magnet produces a shift of the filter support with respect to the x‐ray beam, thus altering the compensation achieved before angulation. This paper contains a description of a system of two servomechanisms which senses the change in compensation and provides correcting motions to restore proper filter position. Particular emphasis is given to items of technique which contributed to the success of this development.

ISSN:0034-6748    

DOI:10.1063/1.1715642

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A study of the response of the sodium iodide scintillation counter to photons in the energy range from 10 to 1500 kev has shown the presence of a significant nonlinearity. Response curves are given for a number of crystals of different dimensions.

ISSN:0034-6748    

DOI:10.1063/1.1715643

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

The ratio of maximum to minimum pulse sizes which can be simultaneously recorded by a kick sorter is limited by the curvature of the characteristic of its biased amplifier over a finite region of input potentials. The extent of this region can be reduced from a few volts to about 10 millivolts by including the nonlinear elements of the amplifier in its negative feedback loop. An amplifier is described which embodies this principle and also provides a discriminator and gate circuit.

ISSN:0034-6748    

DOI:10.1063/1.1715644

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

Apparatus especially designed for studying electron paramagnetic resonance is described and discussed. A magnet of novel yokeless design is presented. Field stabilization and modulation procedure is considered. The microwave sample cavity is analyzed to determine conditions for optimum operation. The klystron stabilization problem is examined. Appropriate lumped circuits for low‐frequency operation are described. The signal amplification and presentation system is treated in detail.

ISSN:0034-6748    

DOI:10.1063/1.1715645

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

This paper describes a method for the measurement and photographic recording of electron density loss in an ionized gas utilizing a microwave system operating near 9400 Mc. The region between initial density level (upon removal of a 24.5‐Mc ionizing voltage) and 500 &mgr;sec later was investigated. Examples of results obtained for commercial neon using this method of measurement are included. In general, it was observed that for commerical neon 90&percent; of the electron density loss occurred within the first 250 &mgr;sec after removal of the ionizing voltage. The equipment used along with photographs of the arrangment, and the results obtained are discussed briefly.

ISSN:0034-6748    

DOI:10.1063/1.1715646

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

In order to reduce the power requirements and heat dissipation in multichannel pulse‐height analyzers with parallel digital storage, we have devised and tested a low‐wattage scale‐of‐two employing filamentary subminiature tubes. These units are designed for use in scales of 16 or 32 and exhibit great reliability and long life. The resolving time is 5 &mgr;sec with grid‐catching diodes and 13 &mgr;sec unaided. For greater reliability in very long cascades and for battery operation, a Higinbotham version has been devised. Both designs promise extremely long life and may be useful wherever bistable switching circuits are used.

ISSN:0034-6748    

DOI:10.1063/1.1715647

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A friction test apparatus has been developed which permits accurate measurements under high vacuum. Sliding motion inside the vacuum chamber is accomplished by magnetic coupling through the chamber wall. The lag angle between the magnets, observed by means of stroboscopic illumination, measures the friction. Calibration of the magnetic coupling is obtained from the period of oscillation of the driven magnet with respect to the driving magnet.

ISSN:0034-6748    

DOI:10.1063/1.1715648

出版商:AIP    

年代:1956

数据来源: AIP