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At least 55 records · Page 3

Research in particles and fields

Investigations, by particle-detectors flown on spacecraft, of the astrophysical aspects of cosmic radiation and the radiation environment of the earth are reported along with the research of the interplanetary medium, and planetary magnetic fields. The cosmic ray interactions with the interplanetary and interstellar medium, and radio scintillation theory were also studied.

Vogt, R. E.↗

Particles and fields subsatellite program

Developments in the Particles and Fields Lunar Subsatellite Program are reported. The basic purpose of the program is to provide three subsatellites with one for launch with Apollo 15, and one for launch with Apollo 16. At this time all three subsatellites have been completed except for a few minor changes, and the Flight 1 subsatellite has been successfully placed in orbit for the Apollo 15 CSM with all systems performing satisfactorily. The Flight 2 subsatellite is scheduled for launch on March 17, 1972. The Qualification Unit subsatellite has successfully completed its qualification testing.

Horn, H. J.↗

Particle and flow field holography: A critical survey

A brief background is provided for the fields of particle and flow visualization holography. A summary of methods currently in use is given, followed by a discussion of more recent and unique applications. The problem of data reduction is discussed. A state of the art summary is then provided with a prognosis of the future of the field. Particle and flow visualization holography are characterized as powerful tools currently in wide use and with significant untapped potential.

Trolinger, James D.↗

Magnetic field and particle pressure in the plasma sheet of Jupiter

The results of an analysis of the energetic particle and magnetic field data acquired by the Voyager 2 spacecraft at distances of about 40-70 Jupiter radii on the nightside of the planet are reported. As in a previous study of similar data at distances of greater than about 80 Jupiter radii, the energy densities of ions (primarily protons) is found to be sufficient to provide the diamagnetic depressions measured in the magnetic field intensity as the spacecraft made successive encounters with the nightside plasma sheet. There is some evidence that the percent contribution of the protons to the energy balance decreases with increasing distance from the planet over this radial interval, although this conclusion is dependent upon the assumption that the proton and heavier ion (oxygen) energy spectra are similar.

Lanzerotti, L. J.↗

Particle and field characteristics of the high-latitude plasma sheet boundary layer

Particle and field data obtained by eight ISEE spacecraft experiments are used to define more precisely the characteristics of the high-latitude boundary region of the plasma sheet. A region immediately adjacent to the high-latitude plasma sheet boundary has particle and field characteristics distinctly different from those observed in the lobe and deeper in the central plasma sheet. Electrons over a broad energy interval are 'field-aligned' and bidirectional, whereas in the plasma sheet the distributions are more isotropic. The region supports intense ion flows, large-amplitude electric fields, and enhanced broad-band electrostatic noise.

Parks, G. K.↗

High-latitude dayside electric field and particle measurements

Two rockets carrying electric field and low energy particle instrumentation were launched near noon at 80 deg magnetic latitude. One flight encountered polar cap conditions only while the other traversed part of the polar cusp. Although weak particle precipitation was measured on both flights, bursts of intense magnetosheath-type electron fluxes were detected on the latter. Strong electric fields such as would result from anti-sunward convection were observed during both flights. The measurements are compared with results obtained by other types of space craft and interpreted in the light of those data.

Maynard, N. C.↗

High-latitude day side electric field and particle measurements

Two rockets carrying electric field and low-energy particle instrumentation were launched near noon at 80 deg magnetic latitude. One flight encountered polar cap conditions only, whereas the other traversed part of the polar cusp. Although weak particle precipitation was measured on both flights, bursts of intense magnetosheath-type electron fluxes were detected on the latter. Strong electric fields such as would result from antisunward convection were observed during both flights. The measurements are compared with results obtained by other types of spacecraft and are interpreted in the light of those data. It is concluded that direct access of magnetosheath electrons is very variable and occurs in small regions within a larger overall region.-

Maynard, N. C.↗

A review of electron bombardment thruster systems/spacecraft field and particle interfaces

This paper collates and summarizes information on the field and particle interfaces of electron bombardment ion thruster systems. Major areas discussed are the nonpropellant particles, neutral propellant, ion beam, low energy plasma, and fields. Spacecraft functions and subsystems reviewed are solar arrays, thermal control systems, optical sensors, communications, science, structures and materials, and potential control. An appendix is included to facilitate identification of specific interaction areas.

Byers, D. C.↗

The Apollo 15 and 16 Particles and Fields Subsatellites, 1969-1975

A historical account of how the Particles and Field Subsatellites came to be carried on the Apollo 15 and 16 lunar missions written by one of the principal investigators of the project Kinsey Anderson. Topics covered include: A discussion of general scientific issues surrounding the mission, A summary of research being carried out in the mid to late 1960s regarding lunar particle shadows and magnetotail electric fields, and The development of the subsatellites and their successful releases on the Apollo 15 and 16 missions.

Anderson, Kinsey A.↗

Boundary-Layer Gradients in New Particle Formation Field Campaign Report

Atmospheric new particle formation (NPF) followed by growth of the particles to ~50-150 nm is estimated to account for over 50% of the particles that can activate cloud droplets. As such, NPF and the subsequent growth plays a critical role in our ability to understand how aerosols affect cloud life cycle, properties, and processes and more generally the Earth’s radiative balance. NPF and growth is known to occur throughout the troposphere including in both the boundary layer and the free troposphere. The majority of NPF and growth observations, however, come from surface-based measurements within the boundary layer. Measurements of the vertical distribution of NPF and growth are sparse and thus insufficient to test many of the hypotheses that attempt to explain connections between NPF and boundary-layer transport and meteorology. The purpose of this campaign was to investigate the vertical distribution of NPF and growth at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility’s Southern Great Plains (SGP) observatory.

54 ENVIRONMENTAL SCIENCES↗

Particles and fields subsatellite program

The development and characteristics of the Particles and Fields Lunar Subsatellite are discussed. The basic mission is to investigate two problems in space physics: (1) the formation and dynamics of the earth's magnetosphere and (2) the boundary layer of the solar wind as it flows over the lunar surface. Illustrations of the subsatellites and the mission concepts are included.

Horn, H. J.↗