摘要:

Fission recoil fragments have been observed to produce tracks in AgCl crystals by a process of self-decoration.The decorated regions were studied with transmission optical microscopy and found to havediameters ranging in size up to 5000 Å. Correlation studies indicate that all of the fragments that enteredthe crystal produced observable regions. Fission tracks have been followed for about 11 &mgr;.

ISSN:0021-8979    

DOI:10.1063/1.1931147

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

With an improved grating and instrumentation it has been possible to reinvestigate the 13- to 44 Å regionof the spectrum and obtain cosiderably improved intensities and peak-to-backgroud ratio (P/B). TheK&agr;emission bands of oxygen, nitrogen, and carbon were obtained with extremely good intensities and P/B.The peak intensity for the carbonKband was 24 000 counts/sec with a P/B of 150 for a 1-mA beam currentand a potential of 3500 V. The investigation of theLemission spectra of Cr through Cu has revealed thatthe transition probability for a (d-p) transition is not always greater than that of a (s-p) transition, whenthese transitions involve energy band electrons. It was also found that theLIII/LIIratio is much closer tothe predicted value of 2 than Skinner found. TheMIIMIIIemission bands, and theMINII, III,MIINIlinesof Nb and Mo have been observed for the first time.

ISSN:0021-8979    

DOI:10.1063/1.1931148

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The adiabatic elastic moduli of lead have been measured from 4.2° to 300°K using the ultrasonic pulseecho method. The Debye&thgr;nobtained from the 4.2° K modulus values is 105.3° K and is to be compared withthe&thgr;nof 108° K obtained from specified heat measurements.

ISSN:0021-8979    

DOI:10.1063/1.1931149

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A 15 at. % germanium-tellurium alloy was quenched from the melt at a rate that prevented the formationof a crystalline phase or phases. The transformation of this amorphous alloy to a crystalline state was studiedby transmission electron microscopy. It was observed that the initial crystalline phase precipitates out ofthe amorphous matrix in the form of dendrities. The later stages of crystallization are characterized bygrowth of the dendrites.

ISSN:0021-8979    

DOI:10.1063/1.1931150

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The effect of both electron and proton irradiation of silicon photovoltaic cells is given in terms of the lossof photovoltaic response and the decrease in the lifetime. Analysis of the spectral response shows that asimple carrier diffusion model provides an adequate description of the behavior of the shallow-diffusedjunctions that were investigated, and yields values for the minority carrier diffusion length before and afterirradiation. Most of the photovoltaic response is shown to occur in the base region of the cells, rather thanin the surface layer, and virtually all of the loss of response is caused by defects introduced in the base. Thereciprocal of the lifetime is linear with the cumulative irradiation flux, and is consistent with the loss ofphotovoltaic response. There are significant differences betweenponnandnonpcells under electronbombardment; the former damaging roughly 100 times as rapidly as the latter. Under proton bombardmentthe difference is roughly a factor of three. A comparison of electron, proton, and neutron irradiation suggeststhat the individual lattice displacements produced in electron irradiation are no more effective in producingrecombination than the displacements produced in high concentration in neutron and proton irradiation.

ISSN:0021-8979    

DOI:10.1063/1.1931151

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Epitaxial Si layers grown on (111) Si substrates by vapor decomposition methods often exhibit a triangleand/or line type of surface defect. An investigation of such defects by optical microscopy and particularlytransmission electron microscopy has shown the defects to be stacking faults. The stacking faults usuallycommence at certain points lying in or close to the substrate/layer interface, and develop in a regular manneralong one or more of the three inclined {111} planes. As growth proceeds the stacking faults rapidly increasein area, spread laterally and eventually interact with one another. A simple growth mechanism is proposedbased on the assumption that nucleation centers occasionally go down in incorrect sequence, i.e., small areasof stacking fault form on the (111) plane parallel to the substrate/layer interface. Many of the experimentalobservations can be explained using this model.

ISSN:0021-8979    

DOI:10.1063/1.1931152

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Convenient formulas are deduced, which relate electron densities and collision frequencies of uniformdense plasmas to two standing wave signals of a probing microwave reflected at a plane boundary of theplasma. In an experiment with a uniform afterglow plasma produced in a waveguide, the electron densityfrom2×1013 cm−3to3×1011 cm−3is measured with reasonable value of the collision frequency by using aX-band microwave. The technique provides a mean for detecting an electron density as high as1×1016 cm−3with the X-band microwave.

ISSN:0021-8979    

DOI:10.1063/1.1931153

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The performance characteristics of the parallel pumped magnetostatic amplifier are experimentally determined.The gain bandwidth product and noise figure are measured as a function of pump power and comparedwith the usual parametric amplifier theory. Deviations occur which originate from a broadening of thesignal and idle magnetostatic modes. This linewidth broadening increases with pump power and is due topump saturation effects. When the usual theory for the gain bandwidth and noise figure is corrected, closeagreement is obtained with the experimental data.

ISSN:0021-8979    

DOI:10.1063/1.1931154

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The fusion energies of several oxide mixtures were obtained by measuring the total radiant energy emittedduring the solidification period. Values obtained for 60BeO-40CaO,48CaO-52Al2O3,75CaO-25B2O3, and80BeO-20Li2O(mole %) were, respectively, 200, 85, 160, and 110 cal/g.

ISSN:0021-8979    

DOI:10.1063/1.1931155

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The paper discusses the potential, space-charge and current density distribution in a “magnetic diode,”i.e., in a linear, smooth anode magnetron. The results of the investigations show that when the initial electronvelocities are taken into account, the electron cloud extends much further into the interelectrode space thancould be expected on the basis of a simple Brillouin flow. Furthermore, the density of the electron clouddecreases monotonically as we move away from the cathode. At the same time, the current flowing parallelto the electrodes has a pronounced peak which is situated half way between the edge of the cloud and thecathode. These results are not only of interest in the steady-state theory of linear magnetrons, but they alsothrow new light on the mode of operation of some thermionic power converters.

ISSN:0021-8979    

DOI:10.1063/1.1931156

出版商:AIP    

年代:1962

数据来源: AIP