Strong influence of electron capture on the characteristic X-ray emission following close heavy-ion-atom collisions

Unexpected structures have been observed in the Sn K and Ag K X-ray yields in 1.4 MeV N-1 U+Sn and Pb+Ag collisions at impact parameters below 200 fm. Related gas target measurements suggests that these effects are mainly due to electron capture following strong ejection of outer-shell electrons in such close collisions. At larger impact parameters, the K-vacancy production is established to be dependent on target density and thickness.