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Storm‐Time Configuration Of The Inner Magnetosphere: Lyon‐Fedder‐Mobarry Mhd Code, Tsyganenko Model, And Goes Observations, Chia-Lin L. Huang, Harlan E. Spence, J. G. Lyon, F. R. Toffoletto, H. J. Singer, S. Sazykin Nov 2006

Storm‐Time Configuration Of The Inner Magnetosphere: Lyon‐Fedder‐Mobarry Mhd Code, Tsyganenko Model, And Goes Observations, Chia-Lin L. Huang, Harlan E. Spence, J. G. Lyon, F. R. Toffoletto, H. J. Singer, S. Sazykin

Physics Scholarship

[1] We compare global magnetohydrodynamic (MHD) simulation results with an empirical model and observations to understand the magnetic field configuration and plasma distribution in the inner magnetosphere, especially during geomagnetic storms. The physics-based Lyon-Fedder-Mobarry (LFM) code simulates Earth's magnetospheric topology and dynamics by solving the equations of ideal MHD. Quantitative comparisons of simulated events with observations reveal strengths and possible limitations and suggest ways to improve the LFM code. Here we present a case study that compares the LFM code to both a semiempirical magnetic field model and to geosynchronous measurements from GOES satellites. During a magnetic cloud event ...


Magnetospheric Influence On The Moon's Exosphere, Jody K. Wilson, M. Mendillo, Harlan E. Spence Jul 2006

Magnetospheric Influence On The Moon's Exosphere, Jody K. Wilson, M. Mendillo, Harlan E. Spence

Physics Scholarship

[1] Atoms in the thin lunar exosphere are liberated from the Moon's regolith by some combination of sunlight, plasma, and meteorite impact. We have observed exospheric sodium, a useful tracer species, on five nights of full Moon in order to test the effect of shielding the lunar surface from the solar wind plasma by the Earth's magnetosphere. These observations, conducted under the dark sky conditions of lunar eclipses, have turned out to be tests of the differential effects of energetic particle populations that strike the Moon's surface when it is in the magnetotail. We find that the ...


Lifetimes Of C-60(2-) And C-70(2-) Dianions In A Storage Ring, S. Tomita, J. U. Andersen, H. Cederquist, B. Concina, Olof E. Echt, J. S. Forster, K. Hansen, B. A. Huber, P. Hvelplund, J. Jensen, B. Liu, B. Manil, L. Maunoury Jan 2006

Lifetimes Of C-60(2-) And C-70(2-) Dianions In A Storage Ring, S. Tomita, J. U. Andersen, H. Cederquist, B. Concina, Olof E. Echt, J. S. Forster, K. Hansen, B. A. Huber, P. Hvelplund, J. Jensen, B. Liu, B. Manil, L. Maunoury

Physics Scholarship

C-60(2-) and C-70(2-) dianions have been produced by electrospray of the monoanions and subsequent electron pickup in a Na vapor cell. The dianions were stored in an electrostatic ring and their decay by electron emission was measured up to 1 s after injection. While C-70(2-) ions are stable on this time scale, except for a small fraction of the ions which have been excited by gas collisions, most of the C-60(2-) ions decay on a millisecond time scale, with a lifetime depending strongly on their internal temperature. The results can be modeled as decay by electron ...


Thermal Expansion And Magnetostriction Of The Ising Antiferromagnet Tbni2ge2, G M. Schmiedeshoff, Shawna M. Hollen, S L. Budko, P C. Canfield Jan 2006

Thermal Expansion And Magnetostriction Of The Ising Antiferromagnet Tbni2ge2, G M. Schmiedeshoff, Shawna M. Hollen, S L. Budko, P C. Canfield

Physics Scholarship

We have measured the linear thermal expansion and magnetostriction of the Ising antiferromagnet TbNi2Ge2 along its c-axis from room temperature to 2 K and in magnetic fields to 14 T. We find a magnetic phase diagram that agrees with earlier work and estimate aspects of its uniaxial pressure dependence. We also find a new high field feature near 10 T which may signal the onset of an additional field-induced phase.