First Light from the IMAP-Hi Energetic Neutral Atom (ENA) Imager on the IMAP Mission

The IMAP-Hi Imager is one of three advanced imagers on the Interstellar Mapping and Acceleration Probe (IMAP) designed to remotely measure and detect energetic neutral atoms (ENAs) from the outer heliosphere. These ENAs are formed by charge exchange of ions in a hot plasma with cold ambient neutral atoms, travel in ballistic trajectories from the source plasma, and thus carry crucial information about their source plasma population, enabling observation of the global structure and dynamics of plasma domains across the outer heliosphere and beyond. IMAP-Hi was optimized to measure neutral Hydrogen over the energy range (500 eV – 15 keV) of core and suprathermal solar wind ion populations. IMAP-Hi is significantly more capable than its predecessor IBEX-Hi, with substantially improved energy range, energy resolution, imaging resolution, sensitivity, and background rejection. IMAP-Hi is comprised of two identical ENA imagers, enabling larger combined geometric factor, enhanced viewing near the ecliptic plane (heliospheric nose, tail, low-latitude ribbon, and flanks), and higher temporal cadence of viewing. Hi45 observes a 45° half-angle cone centered on the spin axis in an antisunward direction, whereas Hi90 views perpendicular to the spin axis. Observations from IMAP-Hi, IMAP-Lo and IMAP-Ultra will allow for a transformational advance in our understanding of the interaction between the heliosphere and the local interstellar medium (LISM), and the particle processes occurring in these regions.  We give an overview of IMAP-Hi performance status on early flight operations of IMAP-Hi and present an initial look at the first IMAP-Hi ENA sky maps.