A. Narmann et P. Sigmund, STATISTICS OF ENERGY-LOSS AND CHARGE-EXCHANGE OF PENETRATING PARTICLES - HIGHER MOMENTS AND TRANSIENTS, Physical review. A, 49(6), 1994, pp. 4709-4715
Recent work on mean energy loss and straggling of ions in the presence
of charge exchange has been extended to higher moments. rhe transient
behavior of charge-exchange straggling has been determined as well as
the skewness of the energy-loss profile. Formulas have been found for
the two- and three-state cases where terms that have been well known
in principle could also be written in a way that illustrates their res
pective origin. In addition to the frequently analyzed case of negligi
ble energy loss in charge-changing events, we also mention explicitly
the opposite situation where all energy loss is associated with charge
exchange. The role of transients and skewness is very different in th
e two extremes. As in a previous paper by one of us, the notation has
been kept general such as to allow for both collisional and spontaneou
s events, and no distinction needs to be made between charge exchange
and change of excitation state. Finally we compare our calculations to
recently obtained experimental results.