High formation yields of negative ions in multicharged fluorine - collisionsS. 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+( )-C60 collisions at low velocity ( ). 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