Dr. Robert F. Benson NASA/GSFC, Code 673 Greenbelt, MD 20771 Phone: (301) 286-4037 Fax: (301) 286-1433 Email: Robert.F.Benson@nasa.gov

PRESENT POSITION:

Astrophysicist, Geospace Physics Laboratory
Heliophysics Science Division
NASA/Goddard Space Flight Center

EDUCATION:

B.S., Geophysics, Univ. of Minnesota, 1956
M.S., Physics, Univ. of Minnesota, 1959
Ph.D., Geophysics, Univ. of Alaska, 1963

RESEARCH INTERESTS:

Dr. Benson's main research interests are in linear and nonlinear plasma wave phenomena, ionospheric and magnetospheric physics, and planetary radio emissions. His approach has been to use the terrestrial ionosphere and magnetosphere as a space plasma laboratory. This system is the most readily accessible space plasma for cost-effective high-resolution in situ and remote investigations and some of the processes operating there have similar counterparts elsewhere in astrophysical plasmas. A prime example is the stimulus provided by investigations of auroral kilometric radiation (AKR) to research into the cyclotron maser instability as an important astrophysical radiation mechanism. Another is the application of knowledge gained from the analysis of stimulated plasma emissions in the Earth's ionosphere to the understanding of natural emissions in the Earth's magnetosphere and Jupiter's Io plasma torus and using this knowledge to deduce electron number densities and magnetic field strengths. This research has been mainly based on the analysis of data from ionospheric topside sounders on the Alouette and ISIS satellites, passive receivers on ISSE 3, the low-power sounder (relaxation sounder) on the Ulysses spacecraft, and the bi-static sounder on the joint Canadian/US OEDIPUS C sounding-rocket experiment. Dr. Benson is leading an effort to produce digital records from a selected portion of the original Alouette/ISIS analog telemetry tapes see http://nssdc.gsfc.nasa.gov/space/isis/isis-status.htm. Since some of these data were never processed earlier, the project is essentially providing the unique opportunity of a new satellite mission with old data. He is also a participating scientist on the IMAGE mission (Imager for Magnetopause-to-Aurora Global Exploration) which has been selected for flight on the first Medium-class Explorer (MIDEX) where he is involved in the planning for the Radio Plasma Imager (RPI) to be flown as part of the IMAGE payload which is scheduled for launch on February 15, 2000 http://image.gsfc.nasa.gov/.

EXPERIENCE:

1990 - 1993 -- Chair, International URSI Commission H (Waves in Plasmas)
1988 - 1993 -- NASA member of NATO/AGARD Electromagnetic Wave Propagation Panel
1984 - 1986 -- International URSI Comm. H Editor for Review of Radio Science
1982 - 1984 -- Chair, US National Committee for URSI Commission H
1965 - present -- NASA/GSFC Space Scientist
1964 - 1965 -- NASA/NRC Postdoctoral Research Associate, GSFC
1963 - 1964 -- Asst. Prof., Astronomy Dept., Univ. of Minnesota
1963 -- Asst. Geophysicist, Geophysical Inst. Univ. of Alaska
1959 - 1963 -- Research Associate, Geophysical Inst., Univ. of Alaska
1958 - 1959 -- Teaching Asst. (Phys.); T & R Asst. (Astronomy), Univ. of Minn.
1956 - 1958 -- IGY Scientist in Antarctica, Arctic Inst. of North America
1955 - 1956 -- Research & Teaching Asst., Univ. of Minnesota

SELECTED PUBLICATIONS:

1. Benson R. F., J. L. Green, S. F. Fung, B. W. Reinisch, W. Calvert, D. M. Haines, J. L. Bougeret, R. Manning, D. L. Carpenter, D. L. Gallagher, P. H. Reiff and W. W. L. Taylor, Magnetospheric radio sounding on the IMAGE mission, Radio Sci. Bull., 285, 9-20, 1998; also available from: http://image.gsfc.nasa.gov/ .
2. Benson, R. F., Evidence for the stimulation of field-aligned electron density irregularities on a short time scale by ionospheric topside sounders, J. Atm. and Solar-Terr. Phys., 59, 2281-2293, 1997.
3. Benson, R. F., J. Fainberg, R. A. Hess, V. A. Osherovich and R. G. Stone, An explanation for the absence of sounder-stimulated gyroharmonic resonances in the Io plasma torus by the Ulysses relaxation sounder, Radio Sci., 32, 1127-1134, 1997.
4. Benson, R. F., Ionospheric investigations using digital Alouette/ISIS topside ionograms, in 1996 Ionospheric Effects Symposium , edited by J. M. Goodman, pp. 202-209, Alexandria, Virginia, 1996.
5. Benson, R. F., Comment on "The auroral radiating plasma cavities" by A. Hilgers, Geophys. Res. Lett., 22, 3005-3007, 1995.
6. Osherovich, V. A., R. F. Benson, J. Fainberg, R. G. Stone and R. J. MacDowall, Sounder stimulated Dn resonances in Jupiter's Io plasma torus, J. Geophy. Res., 98, 18751-18754, 1993.
7. Benson, R. F., Elusive upper hybrid waves in the auroral topside ionosphere, in Auroral Plasma Dynamics, Geophysical Monograph 80, edited by R. L. Lysak, pp. 267-274, American Geophysical Union, Washington, DC, 1993.
8. Benson, R. F. and V. A. Osherovich, High-order stimulated ionospheric diffuse plasma resonances : significance for magnetospheric emissions, J. Geophys. Res., 97, 19,413-19,419, 1992.
9. Benson, R. F., Stimulated plasma instability and nonlinear phenomena in the ionosphere, Radio Sci., 17, 1637-1659, 1982.
10. Benson, R. F., and W. Calvert, ISIS 1 observations at the source of auroral kilometric radiation, Geophys. Res. Lett., 6, 479-482, 1979.