摘要:

Widely reported resonances in positive columns are described by a kinetic model in which electrons reflected at the sheath provide a plasma wave reflection mechanism which has been lacking in earlier fluid theories. Application of a weak magnetic field is shown experimentally to destroy the resonances when the gyro‐radius falls below the dimension of the reflection zone.

ISSN:0003-6951    

DOI:10.1063/1.1755085

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Single wavelength operation on twenty‐five emission lines in the range 23 to 57 &mgr; was obtained by using three diffraction gratings to make the laser resonator frequency selective. This technique leads to new emission lines, enhanced output on weak lines, and identical pulse‐to‐pulse emission intensities. These results show that there are strong interactions among the transitions responsible for laser action. They are quantitatively consistent with the assumption that laser action is due to vibration‐rotation transitions of the H2O molecule.

ISSN:0003-6951    

DOI:10.1063/1.1755086

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A heated platinum wire was used in a sealed CO2&sngbnd;N2&sngbnd;He laser system, resulting in increases in output power that were dependent on the initial fill pressure of CO2. The system was also filled with a CO2&sngbnd;He mixture and made to lase. Heating of the platinum wire caused a decrease in output power. It was tentatively concluded that the platinum catalyzes the reaction CO + O → CO2, permitting a higher concentration of CO2in a sealed system than is otherwise possible.

ISSN:0003-6951    

DOI:10.1063/1.1755087

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Experimental results are presented on current‐voltage relations in heteroepitaxial silicon films grown on sapphire. Above a threshold voltage a current is observed which is proportional to the square of the applied voltage, but inversely proportional to the square of the distance. It is interpreted as space‐charge‐limited current. The square law dependence with distance is a deviation from the Mott‐Gurney law of space‐charge‐limited current in solids, which predictsI∝L−3, and is a consequence of the electrode configuration.

ISSN:0003-6951    

DOI:10.1063/1.1755088

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Single high‐intensity pulses having a duration under 5 nsec have been generated by means of multiple stimulated Brillouin scattering (MSBS) from methanol. This was achieved by placing a liquid cell at one end of a giant‐pulse ruby laser cavity and a Fabry‐Perot etalon at the other Laser oscillation builds up at a wavelength where the Fabry‐Perot provides a high reflectivity and MSBS occurs until the wavelength is shifted to a point at which the Fabry‐Perot has a transmission maximum, thus allowing a single pulse of scattered radiation to be coupled out.

ISSN:0003-6951    

DOI:10.1063/1.1755089

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Experimental observations of acoustoelectric oscillations in [110] and [111] oriented InSb at 77°K in the presence of a transverse magnetic field are described. The period of the oscillations in the [110] samples, equal to the interelectrode transit time of a domain at the shear wave velocity for fields near threshold, increases two‐ or three‐fold for higher electric fields. The possible origin of this anomalous period is discussed.

ISSN:0003-6951    

DOI:10.1063/1.1755090

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Measurements of worst‐case memory performance, dispersion, and hysteresis have been carried out on permalloy films that have been annealed at elevated temperatures in various applied magnetic fields. It is found that deterioration is most rapid for specimens subjected to inhomogeneous hard‐direction fields.

ISSN:0003-6951    

DOI:10.1063/1.1755091

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

``Amorphous'' boron filament prepared by chemical‐vapor deposition of boron on tungsten has typical tensile strengths of 400–600 kpsi and flexural strengths of the order of 2 Mpsi, contrary to the Weibull relationship which requires that the ratio of these quantities be about 1.4. Tensile strength measurements on sections of these filaments with the tungsten boride core material removed have given numerous values in the range 1 to 1.6 Mpsi, thus demonstrating that the intrinsic strength of the boron in the filament does satisfy the Weibull criterion and that ``amorphous'' boron is one of the strongest materials known.

ISSN:0003-6951    

DOI:10.1063/1.1755092

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Field‐emission measurements on field‐evaporated (110) tungsten were correlated with direct observation of the atomic configuration of the surface for different degrees of perfection. It is concluded that small perturbations of the (110) plane from atomic perfection produce a significant increase in the field‐emitted current.

ISSN:0003-6951    

DOI:10.1063/1.1755093

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The initial stages of the deposition of silicon on very thin sapphire platelets with exact (0001) orientation by the hydrogen reduction of SiCl4have been observed using transmission electron microscopy.

ISSN:0003-6951    

DOI:10.1063/1.1755094

出版商:AIP    

年代:1967

数据来源: AIP