摘要:

A new concept for archival electron beam accessed memory has recently been proposed. In the write mode, a high intensity electron beam selectively melts columnar bits in a two‐dimensional lattice which is supported by a thin membrane. The force of surface tension transforms the melted columns into droplets. In the read mode, a low intensity beam interrogates the bits. Transmission contrast is generated by the difference in cross‐sectional area of the columnar and spherical bits. We study the relationship between physical target parameters and system performance of such a memory. Monte‐Carlo simulation of the electron beam‐target interaction has been used to design a target consistent with the following system performance goals: (a) 107bit/sec data rate, (b) 1010bit/cm2data density, and (c) 10−9error rate.

ISSN:0021-8979    

DOI:10.1063/1.330491

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Magnetic leakage fields from nonspherical inclusions in magnetic materials are discussed using classical electromagnetic theory. The model used is that of a prolate or oblate spheroidal inclusion embedded in an infinite medium. Deviations from the leakage field behavior of a spherical inclusion are discussed and procedures are suggested whereby one can test for inclusion shape.

ISSN:0021-8979    

DOI:10.1063/1.330492

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The emission intensity of the 535‐nm line of a thallium‐iodide photodissociation laser excited with 193‐nm ultraviolet radiation is measured as a function of pump energy and vapor pressure. Pressure was varied between 4×10−5and 0.13 Torr. No threshold for positive gain has been found experimentally. The measurements and computer simulation indicate a possibility of constructing lasers with extremely low excitation energy.

ISSN:0021-8979    

DOI:10.1063/1.330493

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Hydrogen has been implanted into an SiO2film grown on a Si trapezoid substrate to form SiH and SiOH bonds. Utilizing internal reflection spectroscopy in the near infrared spectral region, we have directly observed the vibration bands of these ‘‘molecules.’’ With the application of a large electric field across this metal‐oxide‐semiconductor structure, the Stark effect of these vibration bands has been observed. The dependence of line intensity and line shape on the applied voltage has been studied. The sharing of voltage between the oxide film and the depletion layer in the Si is seen by its effect on the Stark intensity. These results suggest the feasibility of seeing natural hydrogen molecularly bonded in thermal oxides.

ISSN:0021-8979    

DOI:10.1063/1.330404

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Focused, pulsed, tunable dye lasers have been used to deposit chromium films by multiphoton dissociation of Cr(CO)6. The multiphoton dissociation of Cr(CO)6is strongly wavelength dependent. Large increases in deposition rate occur below 350 nm, where the threshold between initial 1 and 2 photon absorption to the lowest lying dissociative state are reached in Cr(CO)6. Lack of correlation of deposition rate with multiphoton ionization (MPI) resonances, and polarity of a biased electrode in the cell, suggests multiphoton absorption leads to decomposition to Cr atoms followed by ionization. Power dependence of the deposition rates and MPI signals indicate saturation in the focal region for wavelengths 280<&lgr;<340, for pulse energies 0.02–0.2 mJ. Deposition on cell windows not in the focal region also appears saturated at the shorter wavelengths. Films deposited on silicon and quartz substrates appear uniform, with visible evidence of melting and regrowth in the center of the deposits due to heating by subsequent pulses. Isotropic deposition of Cr atoms on the substrate from the gas phase, away from the irradiated spot, was also observed. Auger analysis of films deposited in the focal region suggest that significant quantities of carbon are present in the film. Alloying of the Cr with the underlying Si by laser heating of the substrate is also suggested.

ISSN:0021-8979    

DOI:10.1063/1.330494

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

This paper shows, analytically and numerically, that the capacitance is a slowly changing function of the conductor shape. This slow change can be monitored by a ‘‘shape factor’’ which is independent of the conductor size. Because of this slow change, from the tabulation of the shape factor, the capacitance of many conductors of arbitrary sizes and shapes with both convex and concave surfaces, can be estimated to an error of 5% or less.

ISSN:0021-8979    

DOI:10.1063/1.330495

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

New formulas are derived for the electromagnetic field of a vertical electric dipole in a conducting or dielectric half‐space. These continuously approximate in accuracy the general complex integrals over the entire practical range, yet are quite simple. They supplement similar formulas for the horizontal electric dipole with which they are compared, and provide the means for studying the interference patterns between the direct and lateral components of the waves and the reflection and transmission of lateral waves at boundaries.

ISSN:0021-8979    

DOI:10.1063/1.330496

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Properties of the electromagnetic waves propagating through a helix‐loaded waveguide are investigated, including the important influence of the outer conducting wall on the dispersion properties. A closed algebraic dispersion relation for the eigenfrequency &ohgr; and the axial wave numberkis obtained for arbitrary azimuthal harmonic number. It is shown that in the limiting case, where the outer conducting wall approaches close to the helix, this dispersion relation is reduced to three distinctive modes. These are the transverse electric mode, the transverse magnetic mode, and the helix mode, which can be further simplified to straight lines in the (&ohgr;,k) parameter space. Numerical investigation of the dispersion relation is also presented.

ISSN:0021-8979    

DOI:10.1063/1.330497

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Collisionless single particle trajectories are modeled for a single plasma channel having one section curved in a circular arc. The magnetic field is developed by superposition of straight and curved channel segments. The plasma density gives charge and beam‐current neutralization. High transport efficiencies are found for turning a relativistic electron beam 90° under reasonable conditions of plasma current, beam energy, arc radius, channel radius, and injection distributions in velocity and in position at the channel entrance. Channel exit distributions in velocity and position are found consistent with those for a straight plasma channel of equivalent length. Such transport problems are important in any charged particle‐beam application constrained by large diode‐to‐target distance or by requirements of maximum power deposition in a confined area.

ISSN:0021-8979    

DOI:10.1063/1.330498

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Suboxide thin films of SbOx, TeOx, MoOx, and GeOx(xis smaller than the stoichiometric value for each component) were found to have the property of showing a critical change in their absorption coefficients and refractive indices at elevated temperatures. The thin‐film samples were prepared by evaporating a mixture of the stoichiometric oxide powder and a deoxidization metal powder such as tungsten. The critical temperatures of these thin films are 150, 120, 150, and 280 °C, respectively. The absorption coefficients before and after the heat treatment are 2.5×104(before) and 6.1×104(after), 8×104and 1.0×105, 5.6×103and 1.1×104, and 4.9×104and 1.8×105cm−1, respectively. Their refractive indices are 1.8 (before) and 1.9 (after), 3.1 and 3.5, 1.8 and 2.1, and 2.5 and 2.8, respectively. As determined by x‐ray diffraction analysis, these thin films are composed of very small metal grains and stoichiometric oxide grains. The thermal changes accompanied by the optical constant changes are mainly due to structural changes in the metal grains. These thin films are concluded to have the feasibility of application to optical disk memories of the laser heat‐mode type.

ISSN:0021-8979    

DOI:10.1063/1.330483

出版商:AIP    

年代:1982

数据来源: AIP