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Winckler, J. R.

Publications and source records attributed to Winckler, J. R..

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Echo 2 - Observations at Fort Churchill of a 4-keV peak in low-level electron precipitation

The Echo 2 rocket flight launched from Fort Churchill, Manitoba, offered the opportunity to observe high-latitude low-level electron precipitation during quiet magnetic conditions. Although no visual aurora was evident at the time of the flight, an auroral spectrum sharply peaked at a few keV was observed to have intensities from 1 to 2 orders of magnitude lower than peaked spectra typically associated with bright auroral forms. There is a growing body of evidence that relates peaked electron spectra to discrete aurora. The Echo 2 observations show that whatever the mechanism for peaking the electron spectrum in and above discrete forms, it operates over a range of precipitation intensities covering nearly 3 orders of magnitude down to subvisual or near subvisual events.

Arnoldy, R. L.↗
NASA NTRS1975

Investigation of electron dynamics in the magnetosphere with electron beams injected from sounding rockets

The Electron Echo experiments are described which were conducted with three sounding rockets to study the basic mechanisms by which electrons precipitate from the geomagnetic field to produce auroral X-rays during periods of geomagnetic activity. Echo I (1970) injected electron pulses at low latitude and successfully measured the returning pulses from the conjugate region. Echo II (1972) was launched from high latitude, studied the interaction of electron beams with background radiation as well as beam motion near the rocket, and obtained evidence for a beam plasma instability. Echo III (1974) detected a series of conjugate echoes during the presence of a strong convective field in the magnetosphere and conducted an unsuccessful search for beam bunching at the local plasma frequency. It is shown that the electric field measurement in the ionosphere, using incoherent backscatter radar and detectors on the rocket, was transferred to the equatorial plane as though field lines were equipotentials.

Winckler, J. R.↗
NASA NTRS1974

An investigation of wave-particle interactions and particle dynamics using electron beams injected from sounding rockets

Electrons with energy up to 40 kV have been injected into semi-trapped orbits from sounding rockets at Wallops Island, Virginia, and at Fort Churchill, Manitoba, Canada. By directing the rocket trajectory to have a horizontal component which in direction and speed matched the bounce displacement of the injected electrons, it was possible to detect conjugate echoes at Wallops and possibly at Churchill, and to study the distribution of the echoes in space, time and energy. By combining observations of many echoes, a composite picture can be obtained of the beam patterns. Atmospheric scattering at the conjugate point of Wallops Island has been extensively studied, and the process produces a scale width of 5-10 m, but with an echo intensity which is only 10% of theoretical estimates.

Winckler, J. R.↗
NASA NTRS1974

Investigation of electron dynamics in the magnetosphere with electron beams injected from sounding rockets

This paper describes an empirical study of the basic mechanisms by which electrons precipitate from the geomagnetic field to produce 'auroral X rays' during periods of geomagnetic activity. The study was based on data obtained by the Echo satellites. Echo I, launched in 1970, injected 40 keV, 0.1 amp electron pulses at low latitude (L ? 2.6) and successfully measured the returning pulses from the conjugate region. Electric fields and multiple Coulomb scattering were studied. Echo II, launched in 1972 from high latitude (L ? 8) studied the interaction of the beams with background radiation and the detailed motion of the beams near the rocket. Evidence for a beam plasma instability was obtained. Echo III launched in April 1974, (L ? 5.5) detected a series of conjugate echoes during the presence of a strong convective field in the magnetosphere. It was shown that the electric field measurement in the ionosphere using the incoherent backscatter radar and detectors on the rocket was transferred to the equatorial plane as though field lines were equipotentials.

Winckler, J. R.↗
NASA NTRS1973

Auroral electrojets and evening sector electron dropouts at synchronous orbit

Evidence is presented in support of the concept that, during magnetospheric substorms, ionospheric auroral electrojet currents are directly coupled to the proton partial ring current in the outer magnetosphere. It has been found that for sufficiently isolated substorms the timing of the start of the electron dropout and of its maximum depression is in good agreement with the start and maximum of electrojet activity as indicated by the auroral electrojet index. This correlation suggests a direct coupling between the electrojet currents and the proton partial ring current.

Erickson, K. N.↗
NASA NTRS1973

Electron-proton spectrometer

An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

Winckler, J. R.↗