Donor behavior in indium-alloyed silicon

The anomalous doping behavior of Si regrown from In solution was studied by (1) Schottky barrier evaluation of conductivity type, (2) electron microprobe analysis for phosphorus, and (3) channeling effect measurements for interstitial In. The latter showed In present at ~ 10^19 cm^–3, but not occupying a regular substitutional or interstitial position. A correlation was found in the first two measurements between phosphorus contamination and n-type conductivity. When the In was contacted only by quartz freshly etched in HF, the n-type behavior and phosphorus contamination disappeared. The anomalous doping behavior is most likely due to phosphorus inpurity picked up by the In

A method for reducing sampling jitter in digital control systems

Digital phase lock loop system is designed by smoothing the proportional control with a low pass filter. This method does not significantly affect the loop dynamics when the smoothing filter bandwidth is wide compared to loop bandwidth

Comment on ``Bethe Ansatz Results for the 4f-Electron Spectra of a Degenerate Anderson Model ''

In a recent letter, Zvyagin calculates the density of states for 4f electrons coupled to a conduction band in the framework of the Bethe ansatz (BA) solution for the degenerate Anderson model. It is claimed that the results qualitatively disagree with the results obtained for the same model but using a variational approach. Even the high energy feature in the f-spectral function near the 4f-level energy ef, i.e. the ``normal'' ionization peak (NIP), is argued to be qualitatively different in the two approaches. In the following we point out that this is not the case.Comment: 1 page, RevTeX, no figur

Final state interaction contribution to the response of confined relativistic particles

We report studies of the response of a massless particle confined by a potential. At large momentum transfer q it exhibits \tilde{y} or equivalently Nachtmann \xi scaling, and acquires a constant width independent of q. This width has a contribution from the final state interactions of the struck particle, which persists in the q->\infty limit. The width of the response predicted using plane wave impulse approximation is smaller because of the neglect of final state interactions in that approximation. However, the exact response may be obtained by folding the approximate response with a function representing final state interaction effects. We also study the response obtained from the momentum distribution assuming that the particle is on the energy shell both before and after being struck. Quantitative results are presented for the special case of a linear confining potential. In this case the response predicted with the on-shell approximation has correct values for the total strength, mean energy and width, however its shape is wrong.Comment: 11 pages, 3 figures, submitted to Phys. Rev.

On the explicit finite element formulation of the dynamic contact problem of hyperelastic membranes

Contact-impact problems involving finite deformation axisymmetric membranes are solved by the finite element method with explicit time integration. The formulation of the membrane element and the contact constraint conditions are discussed. The hyperelastic, compressible Blatz and Ko material is used to model the material properties of the membrane. Two example problems are presented

Burst diaphragm flow initiator Patent

Burst diaphragm flow initiator for installation in short duration wind tunnel

Simple quasi-exponential slope generator

Circuitry for digitally generating an exponentially decaying wave function permits discrete values to be sampled from the exponential waveform for comparison with a binary number of specified accuracy. This exponential-decay generator employs a simple binary counter to count in the sequence of exponential decay

Technique minimizes the effects of dropouts on telemetry records

Recorder deficiencies are minimized by using two-channel system to prepare two tapes, each having noise, wow and flutter, and dropout characteristics of channel on which it was made. Processing tapes by computer and combining signals from two channels produce single tape free of dropouts caused by recording process

Short-duration, transonic flow, variable-porosity test section

Short-duration test facility obtains extremely high Reynolds number flows in subsonic, transonic, and supersonic speed ranges, and aids in solving Reynolds number-dependent aerodynamic and thermodynamic problems in design and testing of large, high speed vehicles. The modified blowdown wind tunnel avoids data confusion and aerodynamic noise

Digital data transition tracking loop improves data reception

Transition tracking loop eliminates drifts, leakages, and instabilities inherent in analog filters. Major components are the phase detector, loop filter, voltage-controlled oscillator and timing logic