Europhys. Lett.
Volume 74, Number 6, June 2006
Page(s) 985 - 991
Section Atomic and molecular physics
Published online 24 May 2006
Europhys. Lett., 74 (6), pp. 985-991 (2006)
DOI: 10.1209/epl/i2006-10055-3

High formation yields of negative ions in multicharged fluorine $\chem{F^{{\it
q}+}}$ $\mth{(q=1\tx{--}3)}$- $\chem{C_{60}}$ collisions

S. Martin1, L. Chen1, J. Bernard1, R. Brédy1, M. C. Buchet-Poulizac1, X. Ma2 and B. Wei1, 2

1  Laboratoire de Spectrométrie Ionique et Moléculaire, Université Claude Bernard Lyon 1, UMR CNRS no. 5579 - 43 boulevard du 11 Novembre 1918 69622 Villeurbanne Cedex, France
2  Institute of Modern Physics, Chinese Academy of Sciences - Lanzhou 730000, PRC

received 9 March 2006; accepted in final form 24 April 2006
published online 24 May 2006

We have measured the yield of negative fluorine ions in Fq+( $q=1\tx{--}3$)-C60 collisions at low velocity ( $v
\approx 0.18\un{a.u.}$). These yields are found surprisingly high, up to 7.1% for F+ and 1.1% for F3+, much higher than the yields measured with atomic targets, typically 0.1%. From the measured kinetic energy loss of scattered F- ions we have estimated the impact parameter of the collision. A direct population of the ground state of the negatively charged projectile by a collective electron transfer is proposed as a possible mechanism to account for the high negative ion formation yields.

34.70.+e - Charge transfer.

© EDP Sciences 2006