SWARM STUDY OF DOUBLY CHARGED RARE-GAS IONS IN HELIUM GAS AT VERY LOW
TEMPERATURE
H. Hidaka, H. Tanuma, N. Kobayashi
Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397,
Japan
Helium cluster ions KrHe$_n^{2+}$ (n \leq 39) have been observed when
doubly charged ions Kr$^{2+}$ are injected into a drift tube filled with
helium gas cooled by liquid helium. Charge transfer in Kr$^{2+}$ +He
collisions is observed as a competitive reaction of clustering.
Mobilitiy measurements at very low temperatures and experiments for
another doubly charged rare-gas ions are in progress.