摘要:

A plasma erosion opening switch (PEOS) is used as the opening switch for a vacuum inductive storage system driven by a 1.8‐MV, 1.6‐TW pulsed power generator. A 135‐nH vacuum inductor is current charged to ∼750 kA in 50 ns through the closed PEOS which then opens in <10 ns into an inverse ion diode load. Electrical diagnostics and nuclear activations from ions accelerated in the diode yield a peak load voltage (4.25 MV) and peak load power (2.8 TW) that are 2.4 and 1.8 times greater than ideal matched load values for the same generator values.

ISSN:0003-6951    

DOI:10.1063/1.97897

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

An electron beam with current density greater than 30 A/cm2and total current of 92 A has been generated in 5 &mgr;s pulses by accelerating the electrons from a glow discharge in a narrow gap between two grids. The ratio of the extracted electron beam current to discharge current is approximately 1. The gun also operates in a dc mode.

ISSN:0003-6951    

DOI:10.1063/1.97898

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A hot wall technique was applied to grow PbI2thin films of about 100 nm thickness on cleaved surfaces of CdI2single crystals. The band‐edge exciton absorption spectra were investigated for the films grown in various conditions. A very sharp exciton absorption line of 8.8 meV half‐width was obtained in a PbI2single‐crystal film grown at a 75 °C substrate temperature. The sharpness of the exciton line proved the excellent quality of the PbI2film and the usefulness of the technique.

ISSN:0003-6951    

DOI:10.1063/1.97899

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A highly sensitive photothermal scheme is described, in which the photothermally induced refractive index variation is measured by a specially designed interferometry. The setup is very simple and stable in facilitating practical applications. It can be used for light‐scattering samples, as well as other state samples. Some experiments for detection of both periodic and nonperiodic photothermal refractive index variation are performed.

ISSN:0003-6951    

DOI:10.1063/1.97900

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We present evidence in this study that the moving species under ion mixing conditions are affected by the implantation damage distribution in the sample. This observation holds for metal‐semiconductor, metal‐metal, and semiconductor‐semiconductor systems. The direction of thermal annealing atomic transport appears to play a role in ion mixing as well. When these two factors are in the same direction, only one dominant moving species is observed. When these two factors are in opposite directions, both constituents can contribute to the atomic transport in ion mixing.

ISSN:0003-6951    

DOI:10.1063/1.97901

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Three previously unreported ternary phases of the type NixInP have been observed to be the primary reaction products of the Ni/InP reaction. The first phase, amorphous NixInP(x&bartil;2.7), forms at the Ni/InP interface by a solid‐state amorphization process at low temperatures (T≲200 °C). Amorphous NixInP crystallizes at ∼300 °C to form a hexagonal NixInP phase (a0=0.412 nm andc0=0.483 nm) with a similar composition. A third ternary phase with nominal composition Ni2InP (monoclinic,a0=0.681 nm,b0=0.529 nm,c0=1.280 nm, and &bgr;=95°) nucleates at higher temperatures and is the final reaction product. This final phase is stable at temperatures up to 500 °C in samples capped with SiO2.

ISSN:0003-6951    

DOI:10.1063/1.97851

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A new interferometry technique has been developed that uses only a single laser for both exciting and detecting photothermal displacement, which greatly simplifies the system and the optical alignment. The minimum detectable displacement 10−2A˚/(Hz)1/2is obtained. To examine this setup, we have performed a simulated experiment. And also, we have succeeded in imaging the subsurface flaw in a copper block. The preliminary results demonstrate that this new method is very promising for nondestructive evaluation and other applications.

ISSN:0003-6951    

DOI:10.1063/1.97852

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The potential distribution across the cleaved end face of a forward‐biased GaAs double heterojunction laser diode was mapped using scanning tunneling potentiometry. Space‐charge regions next to the heterojunction interface as well as the electron‐hole recombination region within the active layer are outlined with nanometer resolution. The carrier injection zone in the active layer is observed as a function of junction voltage.

ISSN:0003-6951    

DOI:10.1063/1.97853

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Wafers of float zone Si grown in hydrogen (Si[H]) were annealed at various temperatures in the range of 300–750 °C before irradiation with 5 MeV electrons. It was found that hydrogen‐related deep levels were no longer observed, when the preannealing temperature was above 500 °C (450 °C) in the case of irradiatedn‐type Si[H] (p‐type Si[H]) samples. Similarly, the convergence of annealing temperatures of different irradiation defects towards a common temperature normally observed in Si[H] was no longer observed, if the Si[H] sample had been annealed at or above 550 °C. A dynamic model is proposed to explain the experimental results.

ISSN:0003-6951    

DOI:10.1063/1.97854

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Interfacial reactions between cobalt thin films and single‐crystal GaAs substrates have been studied by means of Auger electron spectroscopy, transmission electron microscopy, and x‐ray diffraction. The interaction starts at ∼325 °C by the formation of a ternary phase, most probably Co2GaAs, which grows highly oriented with respect to the (001) substrate, with a lattice mismatch of ∼−10%. The reaction kinetics has been studied and found to be diffusion controlled with an activation energy of 0.7±0.1 eV. Cobalt was determined as the dominant diffusion species. The oriented ternary phase co‐exists with randomly oriented CoGa and CoAs at the temperature range of 325–500 °C, while at higher temperatures only the binary compounds prevail.

ISSN:0003-6951    

DOI:10.1063/1.97855

出版商:AIP    

年代:1987

数据来源: AIP