摘要:

A very simple technique is reported for charging 25.4‐ and 50.8‐&mgr;m foils of polyfluoroethylenepropylene (FEP) using conducting liquid contacts. At 23°C in laboratory atmosphere, decay time constants exceed 20 years for foils initially charged to 500 V with ethyl alcohol contacts. Measurements of accelerated decay at 100°C are interpreted in terms of rapid injection and trapping of surface charge followed by drift of thermally generated carriers under the internal field of the trapped surface charge.

ISSN:0003-6951    

DOI:10.1063/1.1654252

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Results are presented of an investigation into the flashover of glass and high‐density alumina cylinders 1.25 cm in length between uniform field electrodes in vacuum. Photographs taken with an image‐converter camera with a framing rate of 2×107frames/sec are shown. At approximately 80% of the voltage required to produce a flashover, partial discharges occur. When the voltage applied to the gap is increased to breakdown level, the partial discharges persist as the first stage of a two‐stage arc formation. The development of the discharge is shown to be consistent with a flashover mechanism involving charging of the solid surface by electrons emitted at the cathode.

ISSN:0003-6951    

DOI:10.1063/1.1654253

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Superconducting behavior characteristic of a weak link is found to occur in the low‐resistance state of a bistable nonvolatile switching device, formed by two closely spaced In contacts on Si.

ISSN:0003-6951    

DOI:10.1063/1.1654254

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Using two step‐tunable CO2lasers, we have observed phase‐matched generation of frequencies 70 <&ngr;<110 cm−1by nonlinear mixing in a birefringent ternary semiconductor, ZnGeP2. An observed power of ∼1.7 &mgr;W at 83.37 cm−1gave a signal‐to‐noise ratio of ∼1000 with a Ge:Ga detector. In combination with tunable optical lasers, this technique should yield a tunable source of submillimeter wave radiation for high‐resolution spectroscopy.

ISSN:0003-6951    

DOI:10.1063/1.1654255

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Short‐duration 10.6‐&mgr;m pulses are used to perturb low‐pressure CO2laser discharges. Various spontaneous emissions from the glow discharge are monitored as they return to their steady‐state values. Vibration‐vibration (VV) pumping between CO2(&ngr;3) and CO (produced by dissociation or premixed) as well as N2has been observed in three independent studies. Data obtained from these studies correlate well with each other. When the reciprocal time constant for the VV process is plotted against pressure, a straight line is obtained as predicted by theory. The slope of this line is consistent with rate‐constant data taken from laser‐induced fluorescence experiments.

ISSN:0003-6951    

DOI:10.1063/1.1654256

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Experiments are described in which low‐intensity laser pulses of zero area[∫−∞∞E(z,t) dt=0]are propagated through a degenerate resonantly absorbing medium with greatly reduced absorption. These pulses are constructed either electro‐optically or by allowing a non‐zero‐degree pulse to evolve toward zero area by means of a resonant absorption and reradiation process. We observe the transmission of as much as 65% of the energy of such pulses through a resonant absorber which attenuates the same cw laser bye−&agr;L, with &agr;L≈ 20.

ISSN:0003-6951    

DOI:10.1063/1.1654257

出版商:AIP    

年代:1972

数据来源: AIP