Radiative and predissociation probabilities for the OH A /2/sigma/plus/ state
Weak predissociation effects of hydroxyl compounds electron state on radiative lifetime via phase shift method
Smith, W. H.↗
SEARCH · Engineering Papers
Results for “Phase shift”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Laser vibration analyzer
Instrument system uses laser and optical heterodyne receiver to measure Doppler phase shifts produced on a laser beam by the deflection of the vibrating surface of a structure under test or in operation.
Foster, J. V.↗
Vibration testing and analysis using holography
Time average holography is useful in recording steady state vibrational mode patterns. Phase relationships under steady state conditions are measured with real time holography and special phase shifting techniques. Data from Michelson interferometer verify vibration amplitudes from holographic data.
Source record↗
Molecular collisions. 16: Comparison of GPS with classical trajectory calculations of rotational inelasticity for the Ar-N2 system
Comparison of generalized phase shift treatment with classical trajectory calculations of rotational inelasticity cross sections of Ar-N2 scattering
Pattengill, M. D.↗
Radiative lifetimes of u.v. multiplets in atomic carbon, nitrogen, and oxygen
Radiative lifetimes of UV multiplets in atomic C, N and O, using modified phase shift technique
Hutchison, R. B.↗
Generalized Hylleraas calculation of positron-hydrogen scattering
Positron-hydrogen scattering below positronium pickup threshold by Hylleraas bound technique, discussing phase shifts and linear parameters
Bhatia, A. K.↗
Molecular collisions. XIV
Atom rigid rotor problem, applying generalized phase shift rotational excitation treatment in lowest approximation
Bernstein, R. B.↗
Differential input preamplifier
Preamplifier chops and amplifies very low level output of thermopile infrared detectors that will be used to measure thermal energy flux of Jupiter and its departure from a blackbody spectrum. Output signal has negligible phase shift. AC signal is RC-coupled to input stage of other amplifiers.
Callaway, P. W.↗
Advanced microelectronics research for space applications, phase 2
Negative-resistance circuits with possible space flight applications are discussed. The basic design approach is to use impedance rotation, i.e., the conversion from capacitance to negative resistance, and from resistance to inductance by the phase shift of the transistor current gain at high frequencies. The subjects discussed in detail are the following: hybrid fabrication of VHF and UHF negative-resistance stages with lumped passive elements; formulation of measurement techniques to characterize transistors and to extend the frequency of negative-resistance transistor amplifiers to higher microwave frequencies; and derivation of transistor characteristics required to increase the frequency range of negative-resistance transistor stages.
Gaertner, W. W.↗
Ionosphere total electron measurements as extracted from satellite tracking data
The Goddard Range and Range Rate System (GRARR) determines the range of a spacecraft by measuring the group delay of a modulated wave and the range rate by measuring the Doppler phase shift of the carrier. An analytical technique is presented for obtaining corrections and equivalent total electron content along the vertical, using VHF GRARR data and a radial model of the ionosphere. The results of computation for a representative pass are given, and estimated accuracy is discussed from a statistical view point. Using VHF GRARR data and a radial model of the ionosphere. The results of computation for a representative pass are given, and estimated accuracy is discussed from a statistical view point. Using GRARR range, range rate, and angle tracking data from Explorer 41, values of total electron content on the order of 10 to the 17th to 10 to the 18th power (electrons/sq m) were obtained. These values agree with estimates of the total electron content from ionospheric profiles using f sub o F sub 2 predict data.
Murray, C. W., Jr.↗
Heuristic theory of positron-helium scattering.
An error in a previous modified adiabatic approximation (Drachman, 1966), due to a lack of generality in the form of the short-range correlation part of the wave function for L greater than zero, is corrected heuristically by allowing the monopole suppression parameter to depend on L. An L-dependent local potential is constructed to fit the well-known positron-hydrogen s, p, and d wave phase shifts below the rearrangement threshold. The same form of potential yields a positron-helium cross-section in agreement with a recent experimental measurement near threshold.
Drachman, R. J.↗
Biochronometry; Proceedings of the Symposium, Friday Harbor, Wash., September 4-6, 1969.
Topics discussed include circadian activity rhythms in birds and man, variation of circadian rhythms in monkeys, resetting of circadian eclosion rhythm in fruitflies, the effectiveness of mathematical models of circadian rhythms, the influence of ac electric fields on circadian rhythms in man, the relation between changes in the metabolic rate and circadian periodicity of the resistance of pocket mice to ionizing radiation, the relation between circadian organization and the photoperiodic time measurement in moths, the circadian rhythm of optic nerve potentials in the isolated eye of the sea hare, phasing of circadian temperature rhythms in the pocket mouse by specific spectral regions, the phase-shifting effect of light on circadian rhymicity in the fruifly, hormonal control of circadian rhythms in the fruitfly, metabolically controlled temperature compensation in the circadian rhythm of algae, and circadian rhythms in the chloroplasts of algae. Individual items are abstracted in this issue.
Menaker, M.↗
Time dependent Hartree-Fock treatment of elastic scattering of electrons by H and He/+/.
Time dependent Hartree-Fock theory, in its coupled and uncoupled forms, is used to calculate the elastic singlet p-wave phase shifts for the scattering of electrons by H and He/+/. On comparison with the best available results it is concluded that the coupled scheme, which contains correlation to at least first order, is superior. Levinson's theorem is confirmed.
Jamieson, M. J.↗
Effect of velocity-changing collisions on the output of a gas laser.
A theoretical model for the pressure dependence of the intensity of a gas laser is presented in which only velocity-changing collisions with foreign-gas atoms are included. This is a special case where the phase shifts are the same for the two atomic-laser levels or are so small that deflections are the dominant effect of collisions. A collision model for hard-sphere repulsive interactions is derived and the collision parameters, persistence of velocity and collision frequency, are assumed to be independent of velocity. The collision theory is applied to a third-order expansion of the polarization in powers of the cavity electric field (weak-signal theory). The resulting expression for the intensity shows strong pressure dependence. The collisions reduce the amount of saturation and the laser intensity increases with pressure in a characteristic fashion.
Borenstein, M.↗
Optimum frame synchronization.
This paper considers the optimum method for locating a sync word periodically imbedded in binary data and received over the additive white Gaussian noise channel. It is shown that the optimum rule is to select the location that maximizes the sum of the correlation and a correction term. Simulations are reported that show approximately a 3-dB improvement at interesting signal-to-noise ratios compared to a pure correlation rule. Extensions are given to the phase-shift keyed sync case where the detector output has a binary ambiguity and to the case of Gaussian data.
Massey, J. L.↗
Generalized pseudopotential approach for electron-atom scattering.
A generalized many-electron pseudopotential approach is presented for electron-neutral-atom scattering problems. A calculation based on this formulation is carried out for the singlet s-wave and p-wave electron-hydrogen phase shifts with excellent results. We compare the method with other approaches as well as discuss its applications for inelastic and rearrangement collision problems.
Zarlingo, D. G.↗
Elastic scattering of 600-MeV protons from H, D, He-3, and He-4.
Study of the elastic scattering of 600-MeV protons from light nuclei. Differential cross sections have been obtained for the scattering of protons from hydrogen, deuterium, helium-3, and helium-4. Polarization was measured for deuterium and He-4 nuclei. The p-p cross-section data are in excellent agreement with the predictions from the Livermore phase shifts. Small-angle p-D, p-He-3 elastic scattering data are compared with calculations based on the multiple-scattering theories of Watson and Glauber.
Boschitz, E. T.↗
The oscillator strengths of the SO /A 3Pi/-/X 3Sigma-/ band systems.
The oscillator strengths for these SO transition band systems are calculated using RKR Franck-Condon factors and the radiative lifetime previously derived from electron-beam phase-shift measurements by Smith (1971). The SO transition concerned is of considerable astrophysical importance in the search for SO in the interstellar medium by means of space-based telescopes with monochromators since the transition probability is concentrated, as shown, in relatively few transitions from the ground state.
Smith, W. H.↗