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Lin, R. P.

Publications and source records attributed to Lin, R. P..

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Observation of 38-334-keV interplanetary protons during solar quiet times

The observations were from the particle experiment aboard the Apollo 16 subsatellite which was ejected April 24, 1972 into an approximately equatorial lunar orbit from the Apollo 16 lunar science module. The proton fluxes vary by a factor of about 5 over a six-month period. The proton measurements were made with a pair of surface barrier semiconductor telescopes. The accuracy of the proton flux measurements during times when electrons are present is highly dependent on the accuracy of the electronic channel matching.

Lin, R. P.↗
NASA NTRS1973

The relationship of solar flare electrons to the flare flash phase and type 3 radio bursts

The energy spectrum and temporal behavior of the 10 to 100 keV solar flare electrons observed at 1 AU are interpreted in terms of: (1) the location of the acceleration region, (2) the time of acceleration and duration of the injection into the interplanetary medium, and (3) type 3 radio burst origin at the sun and at 1 AU. For at least some and possibly the majority of electron flare events the density of the acceleration region is approximately 2 X 10 to the 9th power cu/cm, the time of acceleration and release coincides to within minutes of the flash phase as indicated by the type 3 radio burst, and the duration of the release less than or approximately 3 minutes. Evidence for the origin of type 3 radio bursts in 10 to 100 keV electron streams is shown and discussed.

Lin, R. P.↗
NASA NTRS1973

The position and size of radio sources associated with solar electron events

The positions and sizes of the sources of type 3 bursts which are associated with interplanetary electron events ( 45 keV) are observed by the 80-MHz Culgoora radioheliograph. The sizes of the responsible electron streams at 0.6 solar radius in the corona are much smaller than the cones of propagation of the electrons in interplanetary space. Many of the type 3 bursts are shown to be accompanied by a type 5 continuum, and it is argued that the observation of a type 3 to 5 radio burst implies an increased spreading of electrons at heights 0.6 solar radius, consistent with the extent of the propagation cone of the electrons in interplanetary space.

Palmer, I. D.↗
NASA NTRS1973

Acceleration of electrons in solar flares

Observations pertaining to the acceleration and emission of 10 to 100 keV electrons in small solar flares are reviewed. The energy spectrum of the accelerated electrons is obtained from observations of X-rays and escaping electrons. The loss of the electrons through various processes, such as collisions with the ambient medium, escape to the interplanetary medium, and emission of X-rays and radio waves, is considered, and quantitative energy loss estimates obtained for each process. The role of the accelerated electrons in the overall flare mechanism is examined and an attempt is made to develop a consistent picture of a small electron flare.

Lin, R. P.↗
NASA NTRS1972

Detection of interplanetary electrons from 18 keV to 1.8 MeV during solar quiet times.

Observation of a quiet-time component of interplanetary electrons having energies above solar-wind energies and below those characterized as cosmic radiation. The energy spectrum of this component generally falls with energy from 18 keV to 1.8 MeV, but shows a feature in the 100 to 300-keV range. The observed temporal variations of the intensity suggest that the 18 to 100-keV portion is solar and that the 0.3 to 1.8-MeV portion is galactic in origin. Solar and terrestrial neutron-decay electrons appear inadequate to explain the 100 to 300-keV feature.

Lin, R. P.↗
NASA NTRS1972

Evidence for electron excitation of type III radio burst emission.

Type III radio bursts observed at kilometric wavelengths (less than or about equal to 0.35 MHz) by the Ogo-5 spacecraft are compared with greater than 45 keV solar electron events observed near 1 AU by the IMP-5 and Explorer 35 spacecraft for the period from March 1968 to November 1969. Fifty-six distinct type III bursts extending to less than or about equal to 0.35 MHz were observed above the threshold of the Ogo-5 detector; all but two were associated with solar flares. Twenty-six of the bursts were followed less than or about equal to 40 min later by greater than 45 keV solar electron events observed at 1 AU. All of these 26 bursts were identified with flares located west of W09 solar longitude. Of the bursts not associated with electron events only three were identified with flares west of W09, 18 were located east of W09, and seven occurred during times when electron events would be obscured by high background particle fluxes.

Alvarez, H.↗
NASA NTRS1972

Solar-wind and interplanetary electron measurements on the Apollo 15 subsatellite.

Measurements of high-energy solar-wind electrons have been made from a low orbit around the moon. Solar-wind electrons can be identified up to energies of about 3000 eV, at which an electron population of entirely different characteristics becomes dominant. The solar-wind cavity on the moon's antisolar side shows evidence of being filled by plasma coming from the downstream direction. When the direction of the interplanetary field corresponds to solar ecliptic azimuth angles of about 90 deg, a partial solar-wind cavity extends across most of the eastern sunlit side of the moon within 20 deg of the moon meridian. There are localized increases in the 500-eV electron flux over much of the sunlit hemisphere. These increases are interpreted to be the result of an interaction between the solar wind and the moon that deflects some of the solar-wind flow and results in limb shocks.

Anderson, K. A.↗
NASA NTRS1972

Detection of interplanetary electrons from 18 keV to 1.8 MeV during solar quiet times, 1. On the origin of 200 KeV interplanetary electrons, 2.

A quiet time component of interplanetary electrons having energies above solar wind energies and below those characterized as cosmic radiation was observed. Its energy spectrum falls with energy from 18 keV to 1.8 MeV, but it shows a feature in the 100 to 300 keV range. The observed temporal variations of the intensity suggest that the 18 to 100 keV portion is solar and the 0.3 to 1.8 MeV portion is galactic in origin. Solar and terrestrial neutron decay electrons appear inadequate to explain the 100 to 300 keV feature.

Lin, R. P.↗
NASA NTRS1972

Location of the electron acceleration region in solar flares.

Observations of impulsive solar flare X rays (energy greater than 10 keV) by the OGO-5 satellite and the measurements of energetic solar electrons made with the Explorer-35 and Explorer-41 (IMP-5) satellites during the period March 1968-September 1969 have been analyzed in order to determine the ion density in the X-ray source region as well as the location of the electron acceleration region in the solar atmosphere. The ion density in the X-ray source region varies from event to event and lies between 1 and 100 billion ions per cu cm for those events in which the impulsive X-ray emission could be detected; for those events in which no impulsive emission was detected above threshold, the ion density in the X-ray source was less than one billion ions per cu cm. At least in some small solar flares, the region where the electrons are accelerated during the flash phase is located in the lower corona.

Kane, S. R.↗
NASA NTRS1972

Subsatellite measurements of plasmas and solar particles

The experiment with the small scientific subsatellite which was launched into lunar orbit from Apollo 15 is described. The subsatellite was designed to measure plasma and energetic-particle fluxes, vector magnetic fields, and velocity of the subsatellite for determining lunar gravitational anomalies. The theory of particle-shadow formation by the moon solar wind electrons, and energetic-electron fluxes in interplanetary space are discussed along with an analysis of the initial data.

Anderson, K. A.↗
NASA NTRS1972

Subsatellite measurements of plasma and energetic particles

The Apollo 16 particles and fields subsatellite is instrumented to measure (1) plasma and energetic-particle fluxes, (2) vector magnetic fields, and (3) velocity of the subsatellite to a high precision for the purpose of determining lunar gravitational anomalies. Results from the magnetic-field and gravitational-field experiments are discussed. The results obtained from the plasma and energetic-particle detectors are discussed briefly. The plasma and energetic-particles experiment describes the various plasma regimes in which the moon moves, and determines how the moon interacts with the plasma and magnetic fields in the environment.

Anderson, K. A.↗
NASA NTRS1971

Observations of the scatter-free solar-flare electrons in the energy range 20-1000 keV

Observations of the scatter-free electron events from solar active region McMath No. 8905 are presented. The measurements were made on Explorer 33 satellite. The data show that more than 80% of the electrons from these events undergo no or little scattering and that these electrons travel only approximately 1.5 a.u. between the sun and the earth. The duration of these events cannot be accounted fully by velocity dispersion alone. It is suggested that these electrons could be continuously injected into interplanetary medium for a time interval of approximately 2 to 3 minutes. Energy spectra of these electrons are discussed.

Wang, J. R.↗