Ion Electron Spectrometer (IES) observes Solar WindPlasma. IES combines two toroidal top-hat electrostatic analyzers(ESAs) – one for ions, and the other for electrons – in a back-to-back configuration. IES enables STORM to determine solar wind plasma parameters (density, pressure,and velocity) that affect the magnetosphere. Top-hat analyzers have flown on numerous missions for over 25 years and are a well-established technology.
The IES electro-optics are identical to the Rosetta IES sensor; the electronics are modified from MMS HPCA and include a low-voltage power supply board (LVPS). The LVPS has heritage from SwRI-built LVPS boards for the WISE and Kepler avionics subsystems.