TOWARDS IMPROVEMENT OF ETACHA

E. LAMOUR; J-P. ROZET; K. SHARKAS; D. VERNHET; P.D. FAINSTEIN; M.E. GALASSI; C.A. RAMIREZ; R.D. RIVAROLA

Shangai

Conferencia; 15th International Conference on the Physics of Highly Charged Ions (HCI 2010); 2010

Ab initio calculations of charge state distributions of fast ions at the exit of solid targets are useful in many circumstances, as in the context of energy loss in matter and for the design or analysis of atomic or nuclear physics experiments. The ETACHA code was initially developed to calculate charge state distributions of fast few-electrons ions with at most 28 electrons, and based on the calculation of cross sections for monoelectronic atomic collision processes in the independent electron approximation [1]. However, in the present days, many experiments take place in the intermediate velocity regime, where the stopping power is maximum and where there is an active research prospective either on exotic nuclei, atomic physics, etc...(within the SPIRAL2 foreseen facility for instance). In this case, previously used Born1 type calculations break down, and more sophisticated theories are needed. Moreover, more states have to be included. Several improvements have already been made, and at present the model allows to deal with ions carrying up to 60 electrons (n = 4 shell), and more sophisticated theories are used for ionization and excitation cross sections. Forthcoming improvements will concern capture processes in the low velocity regime and possible break-down of the independent electron approximation for many-electron configurations. [1] J.P. Rozet, C. Stéphan and D. Vernhet, Nucl.Inst. and Meth. B 107, 67-70 (1996)