RESONANCE STRUCTURE IN ELECTRON-COLLISION INDUCED ALIGNMENT OF CORE-EXCITED ATOMIC STATES\raise1.2ex\hbox{$\,*$}

A.N. Grum-Grzhimailo,$^\star$ K.~Bartschat,$^\sharp$ B. Feuerstein$^\dagger$ and W. Mehlhorn$^\dagger$

$^\star$~Institute of Nuclear Physics, Moscow State University, Moscow 119899, Russia
$^\sharp$~Department of Physics and Astronomy, Drake University, Des Moines, IA 50311, U.S.A.
$^\dagger$~Fakult{\"a}t f{\"u}r Physik, Universit{\"a}t Freiburg, D-79104 Freiburg, Germany 

The electron-collision-induced alignment of the Na$\rm ^*(2p^53s^2)^2P_{3/2}$ autoionizing state was determined 
experimentally via the anisotropic emission of the autoionization electrons in the impact energy range from 
threshold to 100~eV. Negative-ion resonance structures in the alignment of an autoionizing state near threshold 
were observed for the first time. For impact energies up to 80~eV, predictions from $R$-matrix calculations 
successfully reproduce the broad-scale energy dependence of the alignment.