ISSN:0034-6748    

DOI:10.1063/1.1770011

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A description is given of a voltage generator and ion tube which are enclosed in a vertical 100 lb./in.2pressure enclosure 18 feet in diameter. Performance characteristics, voltage steadiness, and limitation to a present maximum of 3 Mv are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1770012

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A grid imposed between the filament and target of a demountable high vacuum type x‐ray tube is modulated in synchronism with the full‐wave rectified voltage impressed on the tube, by means of a square‐wave generator. The grid potential varies in such a manner that the electron current flows only when the voltage is sufficiently high to excite theKseries. For the MoK&agr; radiation at 30.8 kv peak voltage an increase in efficiency of 29 percent is realized with the grid modulated. With a peak voltage of 38.2 kv a gain in efficiency of 18 percent is noted, or the x‐ray intensity may be increased by this amount without altering the target heating.

ISSN:0034-6748    

DOI:10.1063/1.1770013

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A simple stabilizer for a cyclotron magnet is described, which stabilizes the voltage across the magnet within one part in 2000. It acts as a variable resistance in parallel with the generator field, which remains shunt connected to the armature.

ISSN:0034-6748    

DOI:10.1063/1.1770014

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A description is given of the design and operation of a circuit employing gas‐filled tetrodes to maintain constant electron emission in an ionization gauge by controlling the filament temperature. Performance data is given to show that variations in the electron emission due to fluctuations in line voltage or changes in the pressure in the ionization gauge have been to a large extent eliminated. Operating experience with the circuit over a considerable period has shown it to be highly satisfactory.

ISSN:0034-6748    

DOI:10.1063/1.1770015

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

An instrument is described which records directly the deflections of a light beam pointer without recourse to photographic development processes. The recording is easily accomplished at pen speeds of 12.7 cm per second across 25 cm of chart without ``hunting'' taking place. Essentially the basic idea of this recorder is that the pen follows the light beam from an external galvanometer by mounting a double cathode photo‐tube on the pen carriage so that both move as a unit. By means of vacuum tube amplifiers operating a reversible motor, the pen carriage moves to the left when the light beam deflects to the left on to the left photo‐tube cathode and to the right when the right photo‐tube cathode is exposed. A movement of the light beam as small as 0.1 mm causes a corresponding movement of the pen. The instrument has been satisfactorily used, with considerable saving in time, for recording current‐voltage curves in polarographic analysis, for obtaining infra‐red absorption curves, and for recording ion currents in mass spectrographic work.

ISSN:0034-6748    

DOI:10.1063/1.1770016

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A new quartz spectrograph for absorption spectrophotometry is described. The method is a modification of the usual photographic method. A very wide spectrogram is divided into transverse comparison strips by means of a grid over the photographic plate, as first proposed by Jones. The instrument offers certain important advantages, among which are high speed, predetermined spectral distribution of absorption data, certainty of obtaining values at absorption maxima and other definite wave‐lengths, need for fewer photographic plates, and applicability to solids as well as to solutions and other liquids.

ISSN:0034-6748    

DOI:10.1063/1.1770017

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

An a.c. operated photoelectric turbidity comparator which has been found useful in assaying physiologically active substances by measuring the growth of micro‐organisms is described. A special feature is that the power supply for both the amplifier and the light source is electronically stabilized.

ISSN:0034-6748    

DOI:10.1063/1.1770018

出版商:AIP    

年代:1942

数据来源: AIP

摘要:

A sensitive indicator of pressure change has been constructed which utilizes a thin organic film as one of a pair of interferometer reflectors. Displacement of the film with respect to a fixed glass plate results in a shift of interference fringes. The film, being very thin, is extremely sensitive to pressure changes.

ISSN:0034-6748    

DOI:10.1063/1.1770019

出版商:AIP    

年代:1942

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1770020

出版商:AIP    

年代:1942

数据来源: AIP