Projectile Structure Effects on Neon K X-Ray Production by Fast, Highly Ionized Argon Beams

An already large yield of neon K x-rays produced by a high-energy (60-80 MeV) stripped argon beam has been observed to undergo a tenfold increase when the projectile charge state is changed from +6 ($2p$ shell full) to {~} + 14 ($2p$ shell empty). This increase may be understood qualitatively in terms of a transfer of $1s$ neon electrons to the empty $2p$ shell of the more highly stripped ions during collisions. Other possible interpretations are also discussed.