摘要:

In this letter, results are reported on the first surface‐acoustic‐wave pulse compression filter using the reflective dot array (RDA). The results show that the RDA approach is capable of producing very‐high‐performance pulse compression filters, comparable to RAC devices, but at much lower cost. The primary advantage of the RDA is that it is part of the same mask as the transducers, thus permitting single‐step fabrication.

ISSN:0003-6951    

DOI:10.1063/1.89484

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

In BaTiO3crystals possessing bulk photovoltaic behavior a photoinduced polarized Rayleigh scattering was observed. The results show that illumination of BaTiO3crystals creates an inhomogeneous distribution of spontaneous polarization (photofluctuations) which are responsible for both effects, the bulk photovoltaic effect and the polarized Rayleigh scattering. The pseudo‐Jahn‐Teller effect which was introduced earlier for other photoferroelectric phenomena is assumed to be responsible for the creation of these photoinduced fluctuations.

ISSN:0003-6951    

DOI:10.1063/1.89471

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

By combination of a liquid‐crystal light valve with a simple additional device, a great brightness intensification of the displayed digits is achievable solely by efficient use of ambient light. In a plastic plate, doped with fluorescent molecules, ambient light is collected, guided, and finally emitted at the digit segments. Promising experimental results have been obtained.

ISSN:0003-6951    

DOI:10.1063/1.89476

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The growth of the pyroelectric coefficientp(T) of 6‐&mgr;m films of polyvinylidene fluoride during poling with a field of 100 MV m−1was measured for the poling temperaturesTp=100, 80, 60, 40, and 20 °C. DecreasingTpgreatly reduced the growth rate ofp(T), but not the value ofp(T) attainable by prolonged poling. For the best poled filmsp(T) increased with the film temperatureTfrom 30 &mgr;C m−2 K−1at 0 °C to 55 &mgr;C m−2 K−1at 80 °C. The poling period required forp(20 °C), the room‐temperature value ofp(T), to reach 25 &mgr;C m−2 K−1ranged from 0.5 min atTp=100 °C to 8000 min atTp=20 °C.

ISSN:0003-6951    

DOI:10.1063/1.89478

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Using a time‐of‐flight spectroscopic technique, measurements were made of the ion energy distributions of very fast ions and thermal ions produced when a 7–15‐J 100‐psec Nd : glass laser pulse (1.06 &mgr;m) strikes a (CH2)nslab target. Ion energies greater than 0.5 MeV have been observed for the first time with this technique of measurement. A simultaneous comparison is made between the signal of an ion charge collector placed 30 cm from the target and the intensity of the C VI 3434‐A˚ ion line at 1 cm from the target.

ISSN:0003-6951    

DOI:10.1063/1.89479

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Submillimeter‐wave modulators and switchable polarizers have been fabricated from VO2thin films deposited on sapphire substrates. By passing electric current pulses through elements made from these films, the films can be thermally cycled through the insulator‐to‐metal transition that occurs in VO2at about 65 °C. In the insulating state, the films are found to have negligible effect on the transmission at submillimeter wavelengths, while above the phase transition the transmission is strongly reduced by the free‐electron effects characteristic of a metal. Other possible applications of such switchable VO2elements include variable bandpass filters and diffraction grating beam‐steering devices.

ISSN:0003-6951    

DOI:10.1063/1.89480

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Calculations have been carried out for the photoionization cross sections of excited states of atomic argon and krypton, relevant to the KrF laser. At &lgr;=2486 A˚, it is found that photoabsorption due to the3P0,2metastable states is relatively unimportant, while the cross sections for the first excitedpstates are large (∼4.5 ×10−18cm2).

ISSN:0003-6951    

DOI:10.1063/1.89481

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

We show that cadmium telluride is a promising material for semiconductor‐electrolyte solar cells. Polycrystallinen‐type CdTe, in contact with an aqueous solution of SnCl2, forms a well‐defined Schottky barrier. The efficiency in sunlight is 4.8%. The cell shows a drift of characteristics with time that may be associated with a low rate of formation of hydroxide on the surface. However, operating stability is relatively good compared with other semiconductor‐electrolyte cells that have been reported in the past.

ISSN:0003-6951    

DOI:10.1063/1.89482

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Spherical glass shells filled with deuterium‐tritium gas have been used as cryogenic targets in neutron‐producing experiments. Experiments were performed under cryogenic conditions to determine the state and form of the fuel at the time of arrival of the laser pulse in target interaction experiments. The results from neutron‐producing experiments indicate that cryogenic targets implode significantly better than room‐temperature targets under comparable experimental conditions and that the neutron production for cryogenic targets is significantly greater than for equivalent targets at room temperature.

ISSN:0003-6951    

DOI:10.1063/1.89483

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Entrapment of 10–160‐keV xenon implanted under UHV conditions in polycrystalline aluminum has been investigated by Rutherford backscattering. The saturation xenon distributions were found to be strongly affected by radiation‐enhanced outdiffusion. Different from silicon the loss of xenon from near‐surface regions of aluminum increases with increasing ion energy. The results are explained in terms of spike‐activated diffusion.

ISSN:0003-6951    

DOI:10.1063/1.89485

出版商:AIP    

年代:1977

数据来源: AIP