
IMAP-Ultra Instrument
IMAP-Ultra is the third instrument, along with IMAP-Lo and IMAP-HI, that is imaging the energies and composition of energetic neutral atoms, or ENAs that traveled from the boundary region of our Solar System toward the Sun. IMAP-Ultra measures ENAs whose energies range from 3-300 kiloelectronvolts (keV.) IMAP-Ultra consists of two identical instruments that are positioned on opposite sides of the spacecraft at different angles. The field of view for IMAP-Ultra90 faces 90 degrees to the spin-axis of the spacecraft and IMAP-Ultra45 at a 45 degree angle to the spin-axis. Together, the IMAP-Ultra pair image the entire celestial sphere.
How It Works
IMAP-Ultra’s unique golden fans form a deflection system that allows only ENAs to enter its aperture, like IMAP-Lo and Hi’s ring structures. The fan blades are biased with a high-voltage to prevent charged solar particles from entering the instrument. ENAs are unaffected by this high voltage and can pass through the fan blades.
As those ENAs pass through the fan blades, they enter the instrument through a slit aperture. Inside they pass through a series of foils that act like a stop watch, by measuring each ENA's time of flight, and therefore its speed. IMAP-Ultra's electronics know when to start the clock, based on the detection of secondary electrons generated off the start foil, when the ENA passes through. The clock stops when the ENA hits the large microchannel plate detector at the back plane of the sensor.
By recording where the ENA hits the back plane microchannel plate, the scientists are also able to determine the direction it came from in the sky. IMAP-Ultra records this information for each ENA that make it through, so that it can build up a precise image of the invisible boundary between our solar system and interstellar space. This information is useful later in helping IMAP scientists to determine the range of energies and types of particles that the Heliosphere is composed of and the quantities of these elements.The directionality of the ENAs is used to map the different quantities of different energies that are coming from the outer heliosphere boundary.
Explore the IMAP-Ultra Model
How We Use IMAP-Ultra Data
Scientists, like IMAP-Ultra lead Matina Gkioulidou, use data from IMAP-Ultra to map the origins in the heliosphere of the ENAs whose energies range from 3-300 keV. The data also help scientists determine the energies and amounts of particles like Hydrogen and Oxygen to help determine the nature of the heliosphere.
Meet the Team
The IMAP-Ultra team, led by Matina Gkioulidou at John Hopkins University APL in Laurel, Maryland, is comprised of over 30 engineers and scientists, from electrical and mechanical engineers to space physicists. The team includes a diverse set of early career and veteran personnel who work closely together to achieve the best science possible.
It has been a great adventure working on the IMAP-Ultra instrument with a team of excellent engineers overcoming every challenge that came our way! During IMAP-Ultra environmental testing, while vibrating it at quite severe launch conditions levels, one of the grids failed during multiple tests. The IMAP-Ultra mechanical team, led by the systems engineer Alex Dupont, came up with a new, robust design, without compromising the science outcome, leading to a successful environmental testing and one of the first instrument deliveries to the spacecraft.
- Matina Gkioulidou, Lead, IMAP-Ultra

The IMAP-Ultra Instrument Team.