Electron Transfer Cross Sections for Highly Charged Ion - Alkali Metal Atom Collisions

H.A.Sakaue, K.Hosaka1), H.Tawara2), I.Yamada, N.Nakamura3), S.Ohtani3), A.Danjo4), M.Kimura5), A.Matumoto6), M.Sakurai7) and M.Yoshino8).

National Institute for Fusion Science, Toki 509-5292, Japan
1) National Physical Laboratory, United Kingdom
2) Max Planck Institute for Nuclear Physics, Heidelberg, Germany
3) The University of Electro-Communications, Chofu 182, Japan
4) Department of Physics, Niigata University, Niigata 950-21, Japan
5) Kochi University of Technology, Kochi 782-8502, Japan
6) Hiroshima Institute of Technology, Hiroshima 731-51, Japan
7) Department of Physics, Kobe University, Kobe 657, Japan
8) Shibaura Institute of Technology, Omiya 330, Japan

We have measured the absolute total electron transfer cross sections in the following processes.Iq++A → I(q-i)++Aj++(j-i)e- q: 6∼30, A: Cs, Rb, K, Na
where q represents the charge of the incident projectile ion, j the number of the electrons initially transferred into the ion from the target atom during the collision, i the final charge change on the incident ion after stabilization. The total cross sections from alkali metal atoms (Cs, Rb, K, Na) in collision with low energy highly charged ions (HCI) have been measured by the initial growth-rate methods. It is shown that the observed total cross sections increase as the charge of the projectile highly charged ion increases and increase up to 10-13cm2. We have already measured the total electron transfer cross sections in HCI-rare gas atom collisions[1] and generalized a scaling law[2] for the electron transfer cross sections in slow collisions of HCI and rare gas atom. This time, we compared the observed alkali metal atom data with rare gas atom data and we found that the cross sections of alkali metal atoms are in proportion to the scaling parameter q/P2 in the same way as cross section of rare gas atom. P is the first ionization potential energy of the target atom. But, the value of the gradient of alkali metal atom targets was different from it of rare gas atom targets. On the other hand, we calculated the cross section of alkali metal atom targets by using the classical-trajectory Monte Carlo (CTMC) method and the data of alkali metal atoms agree with our calculated value. We will explain about the detail in this conference.

References

[1] H.A.Sakaue et al., Fusion Engineering and Design 34-35 (1997) 785-788
[2] M.Kimura et al., J.Phys.B28, L643(1995)