(a).One of the critical unsolved instrumentation problems in experimental ionospheric physics is the measurement of the transport properties of the thermal component of low temperature (T< 1 eV) ionized gas or plasma. Present instruments can only measure the density, the temperature and the bulk flow velocity of thermal plasma. Right now, there are no in situ instruments that are capable of measureing more detailed parameters of a low temperature thermal plasma such as pitch angle distribution, electric current density, pressure anisotropy or heat flow. Measurements of these parameters is vitally needed to stimulate further progress in answering several scientific questions. These questions include verifying and improving models of the thermodynamics of the ionosphere, understanding the electrodynamic interaction of auroral arcs with the E-region, evaluating the dispersion relation of plasma wave modes in the ionosphere, and understanding how downward Birkeland currents are carried and driven. Based on the work of and in conjunction with Dr. T.~S.~Huang from the Physics Department of Prairie View A&M University, we have begun designing an instrument that will be capable of making these measurements. The measurements are directly related to particles' guiding center motion, instead of the trajectory motion as is usually done. This instrument exploits the unique properties of particle guiding center motion in a 2-D or line dipole magnetic field. Particles that enter a region of large 2-D field and applied orthogonal electric field will retain their initial pitch angles and will arrive at an interior detection surface at a location that is a unique function of initial pitch angle, energy, and charge sign.
(b.) New Task
(c.) This proposal requests support for development of a detailed design, constuction of a prototype, and testing of the prototype in the lab. The activity plan calls for year one to be devoted to design, with magnet and mechanical design of the cryostat as the first tasks. Electrcical design of the detector and encoding systems will follow. Construction will be concentrated in year 2. Bench testing in locally available plasma chambers will take place in year 3.
(d.) The scientific questions that can be addressed by the proposed instrument, when built and flown, are directly relevant to the overall scientific objectives of UARS, GGS/ISTP, FAST, and TIMED.
Full Text of Proposal