Hot Plasma Composition Analyzer for the Magnetospheric Multiscale Mission

This paper describes the science motivation, measurement objectives, performance requirements, detailed design, approach and implementation, and calibration of the four Hot Plasma Composition Analyzers (HPCA) for the Magnetospheric Multiscale mission. The HPCA is based entirely on electrostatic optics combining an electrostatic energy analyzer with a carbon-foil based time-of-flight analyzer. In order to fulfill mission requirements, the HPCA incorporates three unique technologies that give it very wide dynamic range capabilities essential to measuring minor ion species in the presence of extremely high proton fluxes found in the region of magnetopause reconnection. Dynamic range is controlled primarily by a novel radio frequency system analogous to an RF mass spectrometer. The RF, in combination with capabilities for high TOF event processing rates and high current micro-channel plates, ensures the dynamic range and sensitivity needed for accurate measurements of ion fluxes between 1 eV and 40 keV that are expected in the region of