Title: A SCALING LAW FOR IONIZATION OF RARE GASES IN FAST FULLY STRIPPED ION IMPACT Authors: Takashi Matsuo*, Toshiyuki Kohno#, Hiroshi Sugawara#, Tadao Tonuma$ and Hiroyuki Tawara** Affiliations: *Tokyo Medical and Dental University, Tokyo, Japan. #Tokyo Institute of Technology, Yokohama, Japan. $RIKEN, Wako, Japan. **National Institute for Fusion Science, Toki, Japan. Summary: We have measured gross, total and partial cross sections for the production of recoil ions in collisions of 6 MeV/amu fully stripped ions with rare gases. A new scaling for the ionization cross sections of rare gases in bare projectile ion impact is proposed.