Electron Loss from Highly Excited States ofH0in Collisions withN3+

Cross sections for electron loss from excited hydrogen atoms in collision with a ${\mathrm{N}}^{3+}$ beam at 40-keV/amu collision energy were determined by use of a crossed-beams experiment. The value of the principal quantum number, $n$, of the excited atoms investigated ranged from 9 to 24. In this range the electron-loss cross section increases as $\sim n^3$, in contrast to the $n^2$ increase predicted by a number of theories.