Sweep Velocity Research Articles

Analysis and Design of Ion-Beam Deposition Apparatus

In order to establish an upper limit on the practicality and usefulness of ion-beam deposition of thin films, an experimental beam-deposition system was assembled which was capable of producing an ideally focused ion beam. The system was designed under the assumptions that the final beam diameter is limited by the thermal velocity spread of the ions and the spherical aberration of the final lens of the optical column. Theoretically, this apparatus is capable of producing a 0.01-cm-diam 6×10−8-A indium ion beam at 100-eV energy. Under these conditions, the predicted deposition sweep velocity would be 0.016 cm/min to produce a 2×10−6-cm-thick indium film. Chromatic aberration was the factor that limited the actual measured spot diameter to 0.075 cm for a beam current of 10−8 A and ion energy of 100 eV. Indium films were deposited in this apparatus with ion energies ranging from 100 to 500 eV (total dose of 7×1017 atom/cm2). Interferometric measurements indicated that these films retained, to some extent, the shapes of the ion distributions across the beam. Sputtering, however, inhibited the complete vertical growth of the deposits. Measurements of the sputtering yield indicated that unity sputtering yield occured at an ion energy of 550 eV, as compared with the predicted energy of 200 eV.

Stored-Energy Retrieval in Ultrasonic Image Converter

The electron beam employed to scan the conversion plate of an ultrasonic image converter serves as a switching device, which momentarily connects individual elements of the plate to the termination. If sufficient time has lapsed since their previous interrogation, these elements possess a considerable amount of stored energy due to resonant vibration. With continuous-wave illumination of uniform intensity, and with constant sweep velocity, the energy flowing to the termination consists of a constant-amplitude component of the same frequency as the driving source, and transient components due to switching from one element to the next. The constant-amplitude component may be associated with the impinging ultrasonic signal and the others associated with release of energy stored in the plate. Calculations show that the signal due to release of stored energy increases with beam sweep velocity, and may exceed the amplitude of the steady-state signal obtained by holding the beam in a stationary position.

On the Bridicka Catalytic Wave of Hydrogen(As a subject of panel discussion of protein wave)

Reviw of the author's researches, with his private opinions, is presented. The problems are claimed to be classified into two groups ; i.e. that of electrode reaction and that of polarographic active pathological substance. Confining to the former, 23 questions are taken out. Along the potential axis, the three regions are coined to facilitate discussion ; capillarity region 0--1.0V., cobalt region -1.0--1.4V., and catalytic region -1.4--2.0V. The sweep velocity of applied voltage for any kind of polarographic methods is requested to be defined and controlled caring for adsorption, dcsorption, change of orientation, transformation, transformation of complex, reformation of different metal complex, and other kind of kinetic factors. The involvement of faradaic current and capacity current are discussed. The complicated behaviors of CoIII the capillarity region which were originally pointed out by Kalous is discussed contrasting the results of A.C. polarographic and oscil-lographic polarographic methods. Current in the catalytic region is understood being much involved accompaning with generation and adhesion of hydrogen gas on the electrode surface and the desorpion of surface active substance, no matter what itself is the depolarizer at the same time or not. From tensammetric consideration, desorption of a surface active substance seems to play a great roll for the doubling of the catalytic wave of hydrogen. The “crossing” of the double peaks was discussed from this point. Redioactivity-potential curve discriminates faradaie current from capacity current, ion-ion redox current, or other kind of current which does not accompany cobalt amalgamation on the electrode surface. It's results (1) show the no disturbance of cobalt reduction even at the potential of the catalytic phenomena, and (2) suggest the reduction of CoII→Co I corresponding the first wave of the splitted cobalt wave at cobalt region. The 3d orbital hydrid complex of CoIII is reduced to the outer orbital (N-shell) CoII complex, after passing through the several transient steps ; disturbance of coordination field by electric field near the working electrode, ligand field theoretical transformation of an activated electron and final acception of reducive electron, followed by reformation of ligand arrangement. The affairs of such complex chemical phenoma is still more complicated by possible mercury complex, π bonded cobalt complex, and desorption from the electrode surface etc.. Morphology of the catalytic wave has been considered in several ways, to explain the mechanism involved. “Chemical differential mechanism” has been taken out for the explanation of the catalytic wave of hydrogenhaving symmetric peak form. The positive current, due to sum of cobalt reduction and catalytic hydrogen reduction, may compensated by the one of following negative current or factors. (1) Atomic hydrogen on the electrode surface is oxidized and the produced H+ is fed to CoSR reforming CoSHR. (2) Hydrogen gas accumulated on the electrode surface protects a part of mass transfer of CoSHR. (3) Due to the desorption and molecular up-set reorientation of CoSHR the chance of H+ reduction is decreased.

Resistance to Rolling and Sliding

Abstract In general a single “coefficient of friction” is inadequate to define the fractional resistance between contacting bodies. It is necessary to know both the inclination of the resultant force line and the offset of this line from the theoretical point of contact. This paper presents results of experiments, which were made to determine the effects of velocity on the inclination, and the offset of the line of action of the resultant force between two disks in peripheral contact. The results indicate that the sliding velocity is of primary importance in determining the inclination of the line of action of the resultant force. It is the sum of the sweep velocities that is of primary importance in determining the offset of the resultant force line. The nature of the relationship between the angle of inclination and the offset of the line of action of the resultant force, and the proximity of the contact conditions to those existing for pure rolling, was investigated but no conclusive results were obtained.

The Radar Display as a Linear Filter

When an intensity-modulated cathode ray tube is fed by an electronic gamma-correction circuit to compensate for the tube power law, the over-all system may be interpreted as a linear filter. It is shown that if the electron distribution within the beam is Gaussian, then (for at least some applications) the corresponding equivalent filter has a Gaussian amplitude characteristic and zero phase shift. Thus, a recent radar tube, the 5FP14A, has a frequency response given by exp [-7.07f <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ] when used on a range of 30 nautical miles. (Here f is expressed in megacycles.) A similar result applies to this tube when used as a flying-spot scanner. If the radar video amplifier is to produce no degradation of this display it must be flat to a frequency 1.2v/w, where v is the sweep velocity and w the spot size. The desirable pulse duration is equal to the time required to sweep past a spot. Simple modifications of these relations are necessary if ground-range sweeps are used.

An automatic field plotter

Solutions of field problems can often be approximately obtained by constructing a 2-dimensional model of the field to be studied in an electrolytic tank. A servomechanism is described which is arranged to follow the equipotential lines that exist in such a model and to plot them automatically. A rotating co-ordinate system is employed to enable the device to trace out closed curves and other multivalued functions. This co-ordinate system is automatically aligned with the equipotential lines to be followed so that the sweep velocity is constant and parallel to the desired curve and correction velocity is normal to this curve. The system is analyzed with particular emphasis on stability and accuracy. The prototype plotter was able to follow curves with a minimum radius of 1/2 inch and maintain an accuracy of 0.5 per cent of maximum travel.