ISSN:0034-6748    

DOI:10.1063/1.1741321

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A ten‐billion volt proton synchrotron design using injection from Van de Graaff generators and betatron starting to reduce the required oscillator frequency range is described. Factors affecting the design of the iron core magnet, its power supply, and associated apparatus are discussed. Cost is roughly estimated as fifteen‐ to twenty‐million dollars.The exposition [E. M. McMillan, ``The synchrotron—a proposed high energy particle accelerator,'' Phys. Rev.68,143 (1945); V. Veksler, ``Concerning some new methods of acceleration of relativistic particles,'' Phys. Rev.69,244 (1946)] and successful test [J. R. Richardson, K. R. MacKenzie, E. J. Lofgren, and B. T. Wright, ``Frequency‐modulated cyclotron,'' Phys. Rev.69,669 (1946)] of the synchrotron principle of magnetic particle acceleration has removed one of the limits to the energy obtainable with magnetic accelerators. Radiation loss [E. M. McMillan, ``Radiation from a group of electrons moving in a circular orbit,'' Phys. Rev.68,144 (1945)] varying inversely as the rest energy of the particle, is negligible for protons even at ten‐billion electron volts. The maximum obtainable energy therefore appears to be limited only by engineering feasibility and available funds. In order to gain some information on these factors a preliminary design of a proton accelerator has been worked out for what is believed to be the largest machine that could be made in the near future without departing from the techniques used on machines at present in operation. Ten‐billion electron volts, which is in the range of energy of some primary cosmic‐ray particles and the requirements for proton pair formation, appears to be attainable within the above restriction.

ISSN:0034-6748    

DOI:10.1063/1.1741322

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

For recording instruments rectangular coordinates are preferred to curved ordinates. The following article describes a method by which an arc, produced by an instrument's hand can be converted into a straight line by means of a guiding device. Simultaneously it will furnish the proof that any unavoidable aberration from the absolute straight line is of no consequence as regards the exactitude of the measuring recorded.

ISSN:0034-6748    

DOI:10.1063/1.1741323

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

An evacuated chamber containing a heavy lathe bed for supporting and aligning optical parts, and means for moving the essential internal components from the exterior, is described. The construction is explained in detail. Stabilized high voltage to thirty kilovolts and stabilized low voltage supplies for energizing electromagnetic lens coils are provided. The equipment may be used to illustrate the operation of such electronic equipment as cathode‐ray tubes, electron microscope and diffraction apparatus, or to study the properties of phosphors and optical components such as lenses, guns, and deflection electrodes.

ISSN:0034-6748    

DOI:10.1063/1.1741324

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

An electronic intensity regulator has been developed which exercises direct control upon the intensity of the source of continuous radiation used in absorption spectrophotometry and which provides regulation at any desired intensity within the limits of the source. The Hanovia hydrogen discharge tube when used with this regulator gives an intensity that changes by less than 0.1 percent for changes of ±10 percent in the line voltage and/or ±2 percent in frequency.

ISSN:0034-6748    

DOI:10.1063/1.1741325

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A coincidence device for use in nuclear experimentation is described. The radiation detectors are secondary electron multiplier tubes of high resolving power and these are connected to a variation of the Rossi‐type coincidence circuit. The resolving time for coincidence appears to be of the order of 10−8to 10−9sec.

ISSN:0034-6748    

DOI:10.1063/1.1741326

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

The pulse period of secondary electron multiplier tubes has been determined by two independent methods. The first method consisted of feeding the pulses on capacitors with variable R.C. and observing the oscilloscope screen. The second method consisted of creating artificial coincidences. Both of these methods give a pulse period ofT<5×10−9sec.

ISSN:0034-6748    

DOI:10.1063/1.1741327

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

The effect of a number of thick radiation shields of infinite thermal conductivity and of a type realizable in practice is analyzed by matrix algebra, and a method for calculating the temperatures of the various shields is also given. For identical thin shields it is found that the ratio of the power required to maintain a radiating surface of emissivity &egr;0at a given temperature withNshields to the power required to maintain the same temperature without shields is given by1+&egr;0f+f2+f3+···fN1&egr;k+1&egr;l−1−1,where &egr;k, &egr;lare the emissivities of the two sides of a shield andfis the fraction of the radiation leaving the inside of thenth shield which is incident upon then−1th shield.

ISSN:0034-6748    

DOI:10.1063/1.1741328

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

DeBarr has derived a formula for the efficiency ofnthick radiation shields with infinite thermal conductivity and diffuse surfaces surrounding a black body source. This analysis has been extended to the general case when the original source has an arbitrary emissivity. A simple procedure for calculating explicitly the temperature of any shield is given, and simple numerical examples are cited. The efficiency of shields which reflect partially diffusely and partially specularly is also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1741329

出版商:AIP    

年代:1948

数据来源: AIP

摘要:

A mercury manometer, of the U tube type, in which the volume of mercury which flows between the arms when a pressure is applied can be measured precisely, is described. The arms of the U tube are made in the form of large diameter, shallow cylinders to give a large flow of mercury for a relatively small pressure change. The flow is measured by determining changes in the volume of mercury in one arm of the manometer. This is done by isolating that arm through the closure of a stopcock contained in the small bore tubing which connects the two arms, and adjusting the level of the mercury to an etch in a capillary; the volume change is then read directly from the position of the end of the mercury thread in a second capillary. The magnification of a pressure change is one‐half the ratio of the cross‐sectional areas of the U tube cylinder and the capillary on which the volume change is noted. Magnifications as high as 4000 have been obtained with this device.

ISSN:0034-6748    

DOI:10.1063/1.1741330

出版商:AIP    

年代:1948

数据来源: AIP