Field emission in high magnetic fields
Strong magnetic fields effect on field emission currents in Bi, Zn, Ta and W
Flood, D. J.↗
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Comparison of the mean photospheric magnetic field and the interplanetary magnetic field
Polarity comparison of solar magnetic field and interplanetary magnetic field
Colburn, D. S.↗
Field-ion, field emission microscopy and related topics, Proceedings of the Seminar, University of Florida, Gainesville, Fla., March 23-27, 1970
Field-ion, field emission microscopy - Conference, University of Florida, March 1970
Source record↗
Near-field far-field transformations using spherical-wave expansions
Spherical wave expansion theory application to near field and far field patterns, using analytical, experimental and numerical data
Ludwig, A. C.↗
Magnetic field measurements by Pioneer 7. 1: Hourly averages of the field elements from 17 August 1966 to 29 October 1967 (Bartel's Solar Rotation 1820 to 1836)
The magnetic observations of Pioneer 7, located in the aftward portion of the disturbed solar plasma caused by interaction with the geomagnetic field, are summarized in graphical form. Hourly averages of the magnetic field elements for Bartel's solar rotation number are shown for each month from August 1966 to October 1967.
Ness, N. F.↗
Magnetic field measurements by Pioneer 6. 1: Hourly averages of the field elements from 17 December 1965 to 5 September 1967 (Bartels solar rotation 1811 to 1834)
Magnetic field data obtained on Pioneer 6 flights are presented in graph form as hourly averages. The spacecraft and magnetic field detector are described. The standard data analysis procedures are also given.
Ness, N. F.↗
Polar-cap electric field distributions related to the interplanetary magnetic field direction.
Data from successive Ogo-6 passes over southern and northern high latitudes are presented to illustrate how grossly asymmetric the distribution of electric field magnitudes can sometimes be. They are also shown to provide an example of the anticorrelation between southern and northern polar-cap magnitude distributions. Signature classification, correlations, and possible relations with interplanetary magnetic fields are discussed.
Heppner, J. P.↗
The relation between the azimuthal component of the interplanetary magnetic field and the geomagnetic field in the polar caps
The recently discovered relation between the azimuthal component of the interplanetary magnetic field and magnetic variations in the earth's polar caps is reviewed. When the IMF azimuthal component is positive (typical of an interplanetary sector with magnetic field directed away from the sun) geomagnetic perturbations directed away from the earth are observed within 8 deg from the corrected geomagnetic pole. When the IMF azimuthal component is negative (typically within toward sectors) the geomagnetic perturbations are directed towards the earth at both poles. These perturbations can also be described by an equivalent current flowing at a constant magnetic latitude of 80 - 82 deg clockwise around the magnetic poles during toward sectors and counterclockwise during away sectors. This current fluctuates in magnitude and direction with the azimuthal component of the IMF, with a delay time of the order of 20 minutes. The importance of this effect for understanding of both solar magnetism and magnetospheric physics is stressed in view of the possibility for investigating the solar sector structure during the last five sunspot cycles.
Svalgaard, L.↗
The relativistic dynamics of a point charge in the field of a plane electromagnetic wave traveling in the direction of a uniform static magnetic field
The motion of a charged particle in electromagnetic fields of various geometric configurations and arising from a variety of sources is of intrinsic interest in electromagnetic theory. The particular configuration consisting of a plane wave propagating in the presence of a static uniform magnetic field whose direction is parallel to the wave normal is examined. The analysis presented here is treated within the context of classical electromagnetic theory. A numerical solution - at least to the approximate Lorentz-Dirac equation - is obtained.
Mitchell, T. P.↗
The relation of variations in total magnetic field at high latitude with the parameters of the interplanetary magnetic field and with DP2 fluctuations
The maximum disturbances from the positive and negative regions of delta B (Bp and Bn, respectively) are investigated with respect to their correlation with (1) the average N-S component, Bz, (2) the average angle with respect to the solar magnetospheric equatorial plane, theta (3) the variance, sigma sub i, and (4) the magnitude, Bi, of the interplanetary magnetic field. These quantities were averaged over a period, T, ranging from 20 min. to 8 hours prior to the measurement of Bp or Bn. Variations (i.e., disturbances) in total magnetic field magnitude were studied utilizing data from the Polar Orbiting Geophysical Observatory satellites (OGO 2, 4, and 6), unofficially referred to as POGO.
Langel, R. A.↗
Optical cross beam field tests at ESSA Haswell Field site, October 1969
A series of tests with both the visible and IR optical cross beam systems was made at the Haswell, Colorado, Field Site of ESSA. This memorandum covers only the details of the test setup and runs. A joint field test program was undertaken by ESSA at a 164 meter (500 foot) meteorological tower. The tower was instrumented with wind sensors, temperature sensors, temperature sensors, fluctuating wind and temperature sensors and humidity sensors. The sensors were located at three elevations: 42, 192 and 162 meters. A movable elevator was also instrumented and could be positioned at any desired location along the tower height. The main object of the cross beam studies was to compare the visible and IR systems. The instruments were also arranged so that direct comparison with the sensors on the tower can be made.
Sandborn, V. A.↗
The relation between the polarity of the interplanetary magnetic field and the polar geomagnetic field
The relation between the azimuthal component of the interplanetary magnetic field and the polar cap geomagnetic field is discussed. The geomagnetic effects can be described as produced by an ionospheric current system encircling the magnetic pole. The sense of the current is clockwise during toward-sectors and reversed during away-sectors. The importance of this very direct solar-terrestrial relation is stressed. A recent magnetic sunspot cycle model is discussed as inferred from this relationship, the basic feature being that the sun reproduces the same sector pattern during every sunspot cycle.
Svalgaard, L.↗
Static and wind tunnel near-field/far-field jet noise measurements from model scale single-flow baseline and suppressor nozzles. Volume 1: Noise source locations and extrapolation of static free-field jet noise data
A test was conducted in the Boeing Large Anechoic Chamber to determine static jet noise source locations of six baseline and suppressor nozzle models, and establish a technique for extrapolating near field data into the far field. The test covered nozzle pressure ratios from 1.44 to 2.25 and jet velocities from 412 to 594 m/s at a total temperature of 844 K.
Jaeck, C. L.↗
On frozen-in field lines and field-line reconnection
The concepts of 'frozen-in magnetic field lines' and 'field-line reconnection', which are frequently used in discussions of the theory of the magnetosphere, have been criticized by Alfven and Falthammar (1971), by Heikkila (1973), and by Alfven (1975). In the present paper, it is demonstrated that both concepts are unnecessary and often misleading. The frozen-in concept is shown to belong to the pseudo-plasma formalism which is useful only in special cases.
Alfven, H.↗
Stellar magnetic fields. 1: The role of a magnetic field in the peculiar M giant, HD 4174
Coronal heating by resonant absorption of Alfvenic surface waves (quiescent), and magnetic tearing instabilities (impulsive), is discussed with emphasis on three principles which may have application to late-type evolved stars. (1) If sq B/8 pi greater than sq. rho V is observed 2 in a stellar atmosphere, then the observed magnetic field must originate in an interior dynamo. (2) Low mass loss rates could imply the presence of closed magnetic flux loops within the outer atmosphere which constrain hydrodynamic flows when the magnetic body forces exceed the driving forces. (3) given that such magnetic loops effect an enhancement of the local heating rate, a positive correlation is predicted between the existence of a corona and low mass loss rates. These principles are applied to the M giant star HD 4174, which is purported to have a kilogauss magnetic field. Several of its spectroscopic peculiarities are shown to be consistent with the above principles, and further observational checks are suggested.
Stencel, R. E.↗
Stellar magnetic fields - The role of a magnetic field in the peculiar M giant, HD 4174
Principles of coronal heating via basic electrodynamic effects, viz., resonant absorption of Alfven surface waves (quiescent) and magnetic tearing instabilities (impulsive), are detailed to argue three principles which may have application to late-type evolved stars. First, if one observes that B-squared/8 pi is much greater than rho times v-squared in a stellar atmosphere, then the observed magnetic field must originate in an interior dynamo. Second, low mass-loss rates could imply the presence of closed magnetic flux loops within the outer atmosphere, which constrain hydrodynamic flows when the magnetic body forces exceed the driving forces. Third, given that such magnetic loops effect an enhancement of the local heating rate, a positive correlation is predicted between the existence of a corona and low mass-loss rates. Application of these principles is made in the case of the peculiar M giant star HD 4174, which is purported to have a kilogauss magnetic field. Several of its spectroscopic peculiarities are shown to be consistent with the above principles, and further observational checks are suggested. Possible application to dMe and RS CVn objects is sketched.
Stencel, R. E.↗
Radar imaging of volcanic fields and sand dune fields: Implications for VOIR
A number of volcanic fields and sand dune fields in the western part of North America were studied using aircraft and Seasat synthetic aperture radar images and LANDSAT images. The capability of radars with different characteristics (i.e., frequency, polarization and look angles was assessed to identify and map different volcanic features, lava flows and sand dune types. It was concluded that: (1) volcanic features which have a relatively large topographic expression (i.e., cinder cones, collapse craters, calderas, etc.) are easily identified; (2) lava flows of different ages can be identified, particularly on the L-band images; and (3) sand dunes are clearly observed and their extent and large scale geometric characteristics determined, provided the proper imaging geometry exists.
Elachi, C.↗
The dynamics of fibril magnetic fields. I - Effect of flux tubes on convection. II - The mean field equations
Observations have established the general fibril state of the magnetic field at the visible surface of the sun. This extraordinary state of the field, in separate intense flux tubes, implies that the convection has a relatively permanent, closed topology, in spite of the large Reynolds number. This paper explores some of the effects of the separate flux tubes on the convective motions, generally pushing the convective cells toward aligning their downdrafts with the flux tubes so as to minimize the dissipation.
Parker, E. N.↗