摘要:

The wide frequency emission band of noise signals which interfere with signals of radio transmitters is used for eliminating these noise signals. They are received separately beside the telemetering frequency and are quenched by a suitable anticoincidence circuit.

ISSN:0034-6748    

DOI:10.1063/1.1718115

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

Performance of a 9‐plate ⅛‐in. gap stainless steel foil spark chamber was tested in close proximity to a 200‐kG pulsed magnetic field. No detrimental effect on efficiency was observed for axial field intensity variation of from 20–100 kG.

ISSN:0034-6748    

DOI:10.1063/1.1718116

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

The construction and performance of high intensity electrodeless arcs powered by a 3‐kW rf oscillator, operating at about 5 Mc, are described. The inherent light intensity which is realized is as great as any system which uses electrodes. These sources have been used with mercury, cadmium, thallium, helium, potassium, rubidium, and cesium. Any substance which exhibits or is at a pressure near 10−3Torr can be converted to a plasma by the technique described. The effectivenss of these arcs for use in Raman spectroscopy is illustrated.

ISSN:0034-6748    

DOI:10.1063/1.1718117

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

A semiautomatic method is described which enables the orientation of metal single crystals to be rapidly determined to within ±1°; it is a scanning method and requires a three‐circle goniometer with automatic drives on two circles at right angles to each other, and a fast acting recorder. A further use of the instrument for the study of the perfection of metal single crystals is also demonstrated.

ISSN:0034-6748    

DOI:10.1063/1.1718118

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

Measurements have been made on the distribution of pressure and hysteresis effects in a tetrahedral anvil apparatus by simultaneously monitoring the resistances of calibration wires placed at various positions in the pyrophyllite tetrahedrons. A pressure gradient of about 1% is observed, and it is therefore suggested that pressure calibration wires may be placed on the tetrahedron face to determine the pressure throughout the tetrahedron volume. This technique will allow pressure calibration when sample porosity is not known and could possibly permit pressure calibration at elevated temperatures.

ISSN:0034-6748    

DOI:10.1063/1.1718119

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

A type Y 440 Hoke valve has been modified so that an 18‐carat gold disk is forced by a captive tool steel driver against a stainless steel seat. Gases in the valve contact only hard solder, stainless steel, the gold disk, and aluminum (or copper). One series of tests with a helium mass‐spectrometer leak detector showed that, with several hundred closures each at temperatures around 450°, room temperature, and 77°K and repeated cycling, the conductance across the seat using a closing torque of 5 ft‐lb was less than 10−10cc(NTP)/sec. The driver is not removed for high‐temperature operation or baking. No galling was experienced using a driver of oil‐hardened tool steel against stainless steel with graphite lubrication. The need for a spring for withdrawal of the gold plate was eliminated by positive withdrawal with the driver. The valve is recommended for applications requiring one or more of the following features: (1) helium leak detector tight closure both from the atmosphere and across the seat; (2) bakeable; (3) all‐metal; (4) operable over the region 450° down to 77°K or lower.

ISSN:0034-6748    

DOI:10.1063/1.1718120

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

Silicon p‐n junction particle detectors present unusual passivation problems because of the shallow diffusions and large exposed junction areas involved. The use of silicon dioxide films for reducing the ambient sensitivity of junction detectors has been investigated, and grown‐oxide films produced with high pressure steam have been studied in detail. The dependence of ambient sensitivity on such parameters as bulk silicon resistivity, diffusant, and diffusion temperature has been investigated. Methods of fabrication of ambient insensitive diodes and more complicated guard‐ring structures are also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1718121

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

The design and operating parameters of two coaxial plasma guns are described. The high speed gun performance depends upon the use of (1) gas valve ports near the muzzle end of the central electrode, (2) an optimized gas diffusion delay time, and (3) a small injected gas load. The 10‐cm‐diam gun employs a low inductance power supply and a light gas load to yield a plasma containing ∼5×1016D+ions with a mean energy of 13 keV. The larger 25‐cm‐diam gun requires more energy and a larger gas load to yield a plasma containing a similar number of D+ions but at a higher mean energy of ∼20 keV. As an example of gun performance, the 25‐cm‐diam gun produces a neutron yield of ≈108when incident upon a D2O ice target located 3 m from the gun muzzle.

ISSN:0034-6748    

DOI:10.1063/1.1718123

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

A simple mechanism has been developed to carry out reciprocating motion in zone refining; this motion pattern provides, in effect, an infinitely long heater. The ingot is raised slowly into a battery of heaters, and is then cyclically moved quickly downward and slowly upward through one interzone distance. The unit includes a programmer that discontinues the refining after one to 100 passes. An easily fabricated heater assembly, suitable for use between 50 and 350°C, is also described.

ISSN:0034-6748    

DOI:10.1063/1.1718125

出版商:AIP    

年代:1963

数据来源: AIP

摘要:

A method of radio telemetering temperature with miniature circuits from magnetically supported spinning rotors is described. The circuits are stable and give rotor temperatures with precision of 0.01°C. They are especially useful in the magnetically supported equilibrium ultracentrifuge but are applicable to all types of high speed rotors.

ISSN:0034-6748    

DOI:10.1063/1.1718126

出版商:AIP    

年代:1963

数据来源: AIP