Ionization states of the anomalous cosmic rays

Ionization states of individual N, O, and Ne ions in the low energy (10-30 MeV/n) anomalous cosmic rays (ACR) are determined in the Anuradha experiment conducted onboard Space Shuttle Spacelab-3 mission during 1985 April-May. The geomagnetic field is utilized as a momentum filter in this experiment to obtain upper limits on the ionization states of individual ACR ions. A combination of an extremely sensitive passive plastic detector and an active electromechanical system allow us to obtain accurate information on the arrival locations and directions of individual ACR ions and hence the threshold rigidity needed by each of these ions to reach the point of their detection in the Spacelab-3 orbit.