摘要:

Negative streamer growth is observed in a highly refined mineral oil for sphere‐sphere electrode configurations. The shape of the streamers is somewhat different from that found in point‐plane geometries. The addition of electron trapping additives accelerates the negative streamer velocity as was found to be the case in point‐plane geometry. Breakdown occurs before the negative streamer crosses the gap and appears to originate at the anode. Very fast positive streamers are, in fact, observed.

ISSN:0003-6951    

DOI:10.1063/1.89682

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A theoretical study of the temperature frequency dependence of a quartz‐crystal oscillator using surface‐wave delay lines is performed and enables one to obtain the first‐ and second‐order frequency temperature coefficients. These theoretical results are in agreement with the corresponding available experimental values, corresponding toSTandYcuts. A new zero first‐order temperature coefficient cut is presented.

ISSN:0003-6951    

DOI:10.1063/1.89683

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The results of imaging experiments for the interfacial regions of four representative solid material joint, composite, and bonds, using a transmission‐type scanning acoustic microscope operating at 150 MHz, are reported. These are (1) Mylar‐epoxy‐Mylar joint, (2) brass‐copper grid‐adhesive‐brass composite, (3) brass‐solder‐brass bond, and (4) silicon‐solder‐copper bond. Flaws, voids, and defects in these specimens have been detected.

ISSN:0003-6951    

DOI:10.1063/1.89684

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Several megawatts of radiation at wavelength as short as 1 mm have been generated by the interaction of an intense relativistic electron beam with a rippled magnetic field.

ISSN:0003-6951    

DOI:10.1063/1.89685

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The LaB6(001) clean surface and its initial oxidation have been studied by UPS, XPS, and work‐function measurements. For the clean surface, a so‐called surface state has been found, and a work function of 2.4±0.1 eV has been measured. The surface state disappears by an oxygen exposure of ∼7 langmuir (L), and the work function increases up to 4.0±0.1 eV. This initial oxidation is not a simple oxygen‐adsorption process but proceeds with the formation of a surface oxide or oxides.

ISSN:0003-6951    

DOI:10.1063/1.89686

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The effect of radiation blistering on the retention of deuterium in the near‐surface region of 200‐keVd+irradiated Cu at 350 K has been studied. Blistering is detected using aninsitumethod based on the scattering of laser light. The incident deuteron beam is used both for implantation and to obtain the dynamic deuterium depth profile. Discrete blisters of approximately 4‐&mgr;m average diameter are found to form rapidly at a well‐defined fluence of (7±1) ×1018d+/cm2. The rate deuterium accumulates in the first 0.4 &mgr;m is found to fall dramatically at the onset of blistering from a steady value, of ∼2% of the implantation rate, to nearly zero. Typical D : Cu loadings at the critical dose for blistering are ∼1 at.%.

ISSN:0003-6951    

DOI:10.1063/1.89687

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Noise properties of a He‐Se laser were investigated. A dispersion relation of fluctuations of side light along the positive column was obtained by using a real‐time digital correlator with bandpass filters. Interpretation of the dispersion relation suggests that the cause of the noise is not just the metal‐vapor density fluctuations, but also the randomlike moving striations.

ISSN:0003-6951    

DOI:10.1063/1.89688

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Significant enhancement of the unsaturated conversion efficiencies of four‐wave sum frequency mixing processes involving autoionizing states in Sr vapor is obtained by utilizing the 5s7s 1S0two‐photon channel and phase matching by frequency adjustment. Extrapolation to low power levels indicates that production of cw vuv radiation may be possible. A saturation effect arising from depletion of one of the fundamental beams by two‐photon absorption is observed.

ISSN:0003-6951    

DOI:10.1063/1.89680

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A single isolated saturated‐absorption feature in127I2using the optically pumped 546.1‐nm Hg laser has been observed with low (∼6 MHz) resolution. The3S1→3P2Hg laser transition can be centered exactly on this feature by varying the N2buffer gas pressure using the measured pressure tuning rate of −9.4 MHz/Torr. This may provide an attractive laser system for absolute wavelength stabilization.

ISSN:0003-6951    

DOI:10.1063/1.89681

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Laser oscillation has been observed in the expansion phase of transversely initiated laser‐produced plasmas of argon, krypton, and xenon at pressures up to 1 atm. All of the experimental evidence indicates that these lasers are of a plasma‐recombination type in which an initially ionized plasma rapidly expands and cools, leading to a high recombination rate and subsequently to an inversion in the next lower ionization stage.

ISSN:0003-6951    

DOI:10.1063/1.89689

出版商:AIP    

年代:1977

数据来源: AIP