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Effective Collision Strengths for Fine-Structure Transitions from the 3s23p5 2P Ground State of Chlorine-like Ni XII
Keenan, F. P.; Bell, K. L.; Matthews, A. +1 more
The R-matrix method is used to compute electron impact collision strengths for transitions in Ni XII from its ground-state fine-structure levels. Sophisticated configuration-interaction wave functions are used to represent the 14 lowest LS target states employed in the R-matrix expansion. By transforming the LS-coupled reactance matrices, and by a…
Electron Gyro Time Measurement Technique for Determining Electric and Magnetic Fields
Paschmann, G.; Vaith, H.; Frenzel, R. +1 more
The paper describes the technique the Electron Drift Instrument (EDI) on CLUSTER employs to measure the flight times of the electrons between the time they are emitted and the time they return after having completed a gyration in the ambient magnetic field. In the presence of an electric field two different trajectories exist which return to the d…
Spectroscopic binary orbits from ultraviolet radial velocities. Paper 28: Omicron Persei
Stickland, D. J.; Lloyd, C.
Measuring Magnetic Field Gradients From Four Point Vector Measurements in Space
Khurana, Krishan K.; Kivelson, Margaret G.; Kepko, Larry
The determination of all nine first order spatial gradients requires the knowledge of differences between the magnetic field measurements made simultaneously at (at least) four different points in space. As the first order differences between measurements are typically very small compared to the background field, even small errors resulting from a…
The ISO-Spectrum of the Young Star HD 100546
Vandenbussche, B.; Waelkens, C.; Malfait, K.
An Italian tracking station for Cassini
Ambrosini, R.; Grueff, G.
We present a feasibility study for a 64 m fully steerable parabolic radiotelescope capable of high efficiency operation at frequencies up to 100 GHz. If funds are made available, and construction rapidly started, the antenna would be available in time to be used as a tracking station for the Cassini radio science experiments.
Observations of galactic cosmic ray modulation during Earth-directed coronal mass ejections
Valtonen, E.; Riihonen, E.; Teittinen, M. +3 more
We describe three cosmic-ray decreases observed by the energetic particle telescope ERNE on board SOHO spacecraft during the period January-May, 1997. The decreases in cosmic-ray proton intensities in the energy range above 50 MeV were observed after the passage of interplanetary shocks on February 9, April 10, and May 15. All the shocks were prod…
The Use of Numerical Simulation in the Design of the Cluster/PEACE "Top Hat" Analyzer Electron Optics
Johnstone, A. D.; Woodliffe, R. D.
The four-spacecraft Cluster mission was to be the first to attempt to measure space plasma gradients in three dimensions. The required accuracy of these gradient measurements poses a unique challenge to the accuracy with which the individual measurements must be carried out. In designing the electron analyzers of the PEACE(Plasma Electron And Curr…
Crystalline Dust Features: A Simple Model
Waters, L. B. F. M.; Bouwman, Jeroen
Infrared, submillimeter, and millimeter observations of the soft gamma-ray repeaters
Waters, L. B. F. M.; Hurley, K.; Kouveliotou, C. +9 more
The Soft Gamma-Ray Repeaters appear to be a completely new manifestation of neutron stars. SGR 1806-20 and SGR 1900+14 may have highly unusual stellar counterparts, whose spectra peak in the far infrared. They have not been detected at submillimeter or millimeter wavelengths. Their infrared spectra appear to contain several components: the photosp…