ENERGETIC NEUTRAL ATOMS

Energetic neutral atoms are generated through charge exchange in the radiation belts and in the ring current region, where the trapped ion populations interact with the gas of the geocorona, and subsequently travel along straight line trajectories to the satellite. By measuring precipitating and escaping energetis neutral atoms (ENA), we thus image the energetic particle fluxes in those areas of the enviroment where the neutral atoms are created. This is a major step forward in the understanding of the global energety balance of the Magnetosphere, and how it interacts with the Solar Wind. At RAL we are involved in a number of instruments designed to detect ENA.

We provided detectors and ultraviolet rejection calibration for ISENA on SAC-B.

We are involved in the MENA Medium Energy Neutral Imager on the both the NASA IMAGE/MIDEX mission and TWINS, a Stereo Neutral Imaging mission using Molniya orbits. See below for a simulated image from IMAGE/HENA

RAPID on Cluster II will also be able to detetect ENA

We will supply the detectors on ASPERA, the Swedish led Neutral Imager on Mars Express, the new ESA mission to Mars.

Space Plasma and Planetary Science at RAL are part of our Solar System Scienceprogram.

This work is funded by

the UK Particle Physics and Astronomy Research Council.