PbK-shell ionization probability in high-energy Xe+Pb collisions

Probabilities for PbK-shell ionization in 5.9-, 7.2-, and 8.5-MeV/a.m.u. Xe+Pb collisions for impact parameters between 10 and 60 fm are reported. The measured probabilities are compared with theories of 1sσ-vacancy production.     

Operator algebras and a theorem of Dieudonne

LetA be aC*-algebra with second dualA″. Let (φ _n)(n=1,...) be a sequence in the dual ofA such that limφ _n(a) exists for eacha εA. In general, this does not imply that limφ _n(x) exists for eachx εA″. But if limφ _n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ _n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem.     

K-shell ionization in 7.5- and 8.6-MeV/a.m.u. U+U collisions at very small impact parameters

K-vacancy production probabilities in elastic 7.5- and 8.6-MeV/a.m.u. U+U collisions are reported for impact parameters less than 15 fm. In 7.5-MeV/a.m.u. U+U collisions the ionization probability rises above the trend indicated by larger impact parameter measurements, increasing to 1.8 vacancies per collision at the smallest impact parameter. The measured probabilities for 8.6-MeV/a.m.u. collisions increase to a maximum value of slightly less than 2 vacancies per collision at the smallest impact parameters. The data is compared to previous results and existing theory.