The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the polar mission

The science objectives of the Toroidal Imaging Mass-Angle Spectrograph (TIMAS) are to investigate the transfer of solar wind energy and momentum to the magnetosphere, the interaction between the magnetosphere and the ionosphere, the transport processes that distribute plasma and energy throughout the magnetosphere, and the interactions that occur as plasmas of different origins and histories mix and interact. The TIMAS instrument addresses these objectives by providing essentially the full 3D velocity distribution function of all ion species within 1/2 of a satellite spin period. The TIMAS is a first-order double focusing (angle and energy), imaging spectrograph that simultaneously measures all mass per charge components from 1 AMU/e to greater than 32 AMU/e over a nearly 360 by 10 deg instantaneous field-of-view. Versatile control of both data acquisition and onboard data compression permit optimal operation in all regions of the magnetosphere to be surveyed by the POLAR spacecraft. (AIAA)