Progress Report on the Turbotrap Development

Dr. John Keller
NASA Goddard Space Flight Center

Energetic neutral atom imaging has proven to be a valuable method for the remote observation of space plasmas. In this technique, plasma ions neutralized by charge-exchange collisions with ambient neutral atoms, are released from the local magnetic and electric fields that constrain them. These atoms travel in straight-line trajectories where they can be observed by remote spacecraft. However because of the low intensity of the sources, neutral atoms, particularly those below a few keV in energy, are difficult to detect. Despite recent successes highlighted by the three neutral atom imagers on the IMAGE spacecraft, improvements are needed to make fainter sources accessible as well as to improve the time, energy, and spatial resolution of the detectors. I will discuss in this talk our work exploring a new concept for detecting and imaging neutral atoms with energies between 10 eV to 10 keV. The proposed technique uses an alkali-vapor charge exchange cell for high neutral to ion conversion. Neutral atoms are ionized by extracting loosely bound electrons from the metal atoms on collision. To date our work has been on the containment of the alkali conversion atoms in the cell using high speed rotating vanes. Incident neutral atoms and converted ions above a few eV in energy pass into and out of the cell with high efficiency. As the title suggests this work is incomplete, therefore the talk will focus on design issues, our computer simulations, and very preliminary results.